A Long Term Extension Study of Ixekizumab (LY2439821) in Participants With Axial Spondyloarthritis

• ClinicalTrials.gov Identifier: NCT03129100
• Recruitment Status: Completed
• First Posted: April 26, 2017
• Results First Posted: June 18, 2021
• Last Update Posted: June 13, 2022
• Sponsor: Eli Lilly and Company
• Information provided by (Responsible Party): Eli Lilly and Company

• Study Type: Interventional
• Study Design: Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: Triple (Participant, Care Provider, Investigator); Primary Purpose: Treatment
• Condition: Axial Spondyloarthritis
• Interventions: Drug: Ixekizumab; Drug: Placebo
• Enrollment: 773

Participant Flow

Recruitment Details

Lead-In (Period 1): 24 weeks (Week 0 to Week 24); Extension Period including Double-Blind, Placebo-Controlled, Randomized Withdrawal-Retreatment (RWR) (Period 2): 40 weeks (Week 24 to Week 64); Long-Term Extension Period (Period 3): 40 weeks (Week 64 to Week 104); Post-Treatment Follow-Up (Period 4): at least 12 weeks and up to 24 weeks after the date of the participant's ETV or last regularly scheduled visit.

Pre-assignment Details

In Period 2, participants who did not achieve sustained remission were assigned to Group A and continued to receive the ixekizumab(IXE) dose regimen that they were receiving during Period 1. Participants who did achieve sustained remission were assigned to Group B (Randomized Withdrawal Extension(RWE) period) and were randomized 2:1 to either continue their IXE dose or to withdraw to placebo. Participants who experienced a flare in group B were retreated with IXE in Retreatment Extension Period.

Arm/Group Title	IXE 80Q4W-Lead-in Period	IXE80Q2W-Lead-in Period	IXE80Q4W-Group A Extension Period	IXE80Q2W-Group A Extension Period	IXE80Q4W-Group B-Randomized Withdrawal Extension Period	IXE80Q2W-Group B-Randomized Withdrawal Extension Period	Placebo-Group B-Randomized Withdrawal Extension Period	IXE80Q2W/IXE80Q2W-Retreatment Extension Period	IXE80Q4W/IXE80Q4W-Retreatment Extension Period	PBO/IXE80Q2W-Retreatment Extension Period	PBO/IXE80Q4W-Retreatment Extension Period	IXE80Q2W-group A Long-term Extension Period	IXE80Q4W-group A Long-term Extension Period	IXE80Q2W-Group B-Randomized Withdrawal Long-term Extension Period	IXE80Q4W-Group B-Randomized Withdrawal Long-term Extension Period	PBO-Group B-Randomized Withdrawal Long-term Extension Period	IXE80Q2W/IXE80Q2W-Retreatment Long-term Extension Period	IXE80Q4W/IXE80Q4W-Retreatment Long-term Extension Period	PBO/IXE80Q2W-Retreatment Long-term Extension Period	PBO/IXE80Q4W-Retreatment Long-term Extension Period	IXE80Q4W-Group A-Escalation Period	IXE80Q4W-Randomized Withdrawal Escalation Period	PBO-Randomized Withdrawal Escalation Period	PBO-follow-up Period	IXE80Q4W-follow-up Period	IXE80Q2W-follow-up Period
Arm/Group Description	Participants received 80 milligram (mg) of Ixekizumab subcutaneously (SC) every four weeks (Q4W) for up to week 24.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) for up to week 24.	Participants continued to receive uninterrupted Ixekizumab 80 mg Q4W subcutaneous dose during the extension period.	Participants continued to receive uninterrupted Ixekizumab 80 mg Q2W subcutaneous dose during the extension period.	Participants in the Ixekizumab 80 mg Q4W treatment group (Lead-in) were re randomized to receive Ixekizumab 80 mg Q4W subcutaneous dose at Week 24 in the randomized withdrawal extension period.	Participants in the Ixekizumab 80 mg Q2W treatment group (Lead-in) were re randomized to receive subcutaneous dose of Ixekizumab 80 mg Q2W at Week 24 in the randomized withdrawal extension period.	Participants were re-randomized to receive subcutaneous dose of placebo at Week 24 in the randomized withdrawal extension period.	Participants in Group B who received Ixekizumab 80 mg Q2W in Period 2 and experienced a flare were retreated with subcutaneous dose of Ixekizumab 80 mg Q2W during the retreatment long-term extension period.	Participants in Group B who received Ixekizumab 80 mg Q4W in Period 2 and experienced a flare were retreated with subcutaneous dose of Ixekizumab 80 mg Q4W during the retreatment long term extension period.	Participants in Group B who received placebo in Period 2 and experienced a flare were retreated with subcutaneous dose of Ixekizumab 80 mg Q2W during the retreatment long term extension period.	Participants in Group B who received placebo in Period 2 and experienced a flare were retreated with subcutaneous dose of Ixekizumab 80 mg Q4W during the retreatment long term extension period.	Participants from "IXE80Q2W group A extension period" continued to receive same treatment that they were receiving at the end of Period 2.	Participants from "IXE80Q4W group A extension period" continued to receive same treatment that they were receiving at the end of Period 2.	Participants from "IXE80Q2W-Group B-Randomized Withdrawal Extension Period" continued to receive same treatment that they were receiving at the end of Period 2.	Participants from "IXE80Q4W-Group B-Randomized Withdrawal Extension Period" continued to receive same treatment that they were receiving at the end of Period 2.	Participants from "Placebo-Group B-Randomized Withdrawal Extension Period" continued to receive same treatment that they were receiving at the end of Period 2.	Participants in Group B who received Ixekizumab 80 mg Q2W in Period 3 and experienced a flare were retreated with subcutaneous dose of Ixekizumab 80 mg Q2W during the retreatment long-term extension period.	Participants in Group B who received Ixekizumab 80 mg Q4W in Period 3 and experienced a flare were retreated with subcutaneous dose of Ixekizumab 80 mg Q4W during the retreatment long term extension period.	Participants in Group B who received placebo in Period 3 and experienced a flare were retreated with subcutaneous dose of Ixekizumab 80 mg Q2W during the retreatment long term extension period.	Participants in Group B who received placebo in Period 3 and experienced a flare were retreated with subcutaneous dose of Ixekizumab 80 mg Q4W during the retreatment long term extension period.	Participants in Group A receiving ixekizumab 80 mg Q4W escalated to ixekizumab 80 mg Q2W in Period 3.	Participants in Group B receiving Ixekizumab 80 mg Q4W escalated to ixekizumab 80 mg Q2W.	Participants in Group B, who received PBO, experienced a flare and retreated with Ixekizumab 80 mg Q4W, escalated to ixekizumab 80 mg Q2W.	Participants did not receive any intervention during Follow-up period.	Participants did not receive any intervention during Follow-up period.	Participants did not receive any intervention during Follow-up period.
Period Title: Lead-In Period (Period 1)
Started	350	423	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Received at Least One Dose of Study Drug	348	423	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Completed	335	406	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Not Completed	15	17	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Reason Not Completed
Adverse Event	2	6	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Lost to Follow-up	2	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Withdrawal by Subject	8	8	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Lack of Efficacy	3	2	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Surgery Programmed	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Period Title: Period2 Extension Period (Group A and B)
Started	0 [1]	0 [1]	255 [2]	318 [2]	48 [3]	54 [3]	53 [3]	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Received at Least One Dose of Study Drug	0	0	255	318	47	54	53	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Completed	0	0	234	312	42	45	32	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Not Completed	0	0	21	6	6	9	21	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Reason Not Completed
Adverse Event	0	0	2	1	0	2	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Death	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Withdrawal by Subject	0	0	13	5	1	1	2	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Physician Decision	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Lack of Efficacy	0	0	2	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Lost to Follow-up	0	0	2	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Experienced Flare	0	0	0	0	5	6	19	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
[1] Only Extension Period participants were included.; [2] Participants who entered extension period (Group A).; [3] Participants who entered extension period (Group B).
Period Title: Period 2 (Retreatment Extension Period)
Started	0	0	0	0	0	0	0	6 [1]	5 [1]	9 [1]	10 [1]	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Completed	0	0	0	0	0	0	0	6	5	8	10	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Not Completed	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Reason Not Completed
Withdrawal by Subject	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
[1] Participants who experienced flare in Group B Extension period.
Period Title: Period3-Long-Term Extension Period A & B
Started	0	0	0	0	0	0	0	0 [1]	0 [1]	0 [1]	0 [1]	306 [1]	177 [1]	45 [1]	42 [1]	30 [1]	0	0	0	0	0	0	0	0	0	0
Completed	0	0	0	0	0	0	0	0	0	0	0	287	146	40	37	21	0	0	0	0	0	0	0	0	0	0
Not Completed	0	0	0	0	0	0	0	0	0	0	0	19	31	5	5	9	0	0	0	0	0	0	0	0	0	0
Reason Not Completed
Adverse Event	0	0	0	0	0	0	0	0	0	0	0	6	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Withdrawal by Subject	0	0	0	0	0	0	0	0	0	0	0	12	7	4	2	0	0	0	0	0	0	0	0	0	0	0
Lost to Follow-up	0	0	0	0	0	0	0	0	0	0	0	1	0	1	1	0	0	0	0	0	0	0	0	0	0	0
Lack of Efficacy	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0
Escalated to IXE80Q2W	0	0	0	0	0	0	0	0	0	0	0	0	24	0	2	8	0	0	0	0	0	0	0	0	0	0
[1] This period is to report Long-Term Extension Period participants
Period Title: Period 3 (Flare)
Started	0	0	0	0	0	0	0	0	0	0	0	0 [1]	0 [1]	0 [1]	0 [1]	0 [1]	6 [1]	4 [1]	11 [1]	15 [1]	0	0	0	0	0	0
Completed	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	6	2	11	12	0	0	0	0	0	0
Not Completed	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	2	0	3	0	0	0	0	0	0
Reason Not Completed
Escalated to IXE80Q2W	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	2	0	3	0	0	0	0	0	0
[1] This period is to report participants who experienced a flare in Period 3.
Period Title: Period 3 (Dose Escalation)
Started	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0 [1]	0 [1]	0 [1]	0 [1]	77 [1]	5 [1]	4 [1]	0	0	0
Completed	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	73	5	4	0	0	0
Not Completed	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	4	0	0	0	0	0
Reason Not Completed
Withdrawal by Subject	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	2	0	0	0	0	0
Physician Decision	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0
Lack of Efficacy	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0
[1] Participants who are eligible for dose escalations.
Period Title: Period 4 (Post Treatment Follow-up)
Started	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0 [1]	0 [1]	0 [1]	25 [1]	223 [1]	453 [1]
Completed	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	22	198	411
Not Completed	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	3	25	42
Reason Not Completed
Death	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0
Lost to Follow-up	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	2	2
Withdrawal by Subject	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	3	20	37
COVID 19 Restrictions	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	2	0
Missed follow-up	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1
Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	2
[1] This period is to report Follow-Up period participants.

Baseline Characteristics

Arm/Group Title		IXE80Q4W-Group A Extension Period	IXE80Q2W-Group A Extension Period	IXE80Q4W-Group B-Randomized Withdrawal Extension Period	IXE80Q2W-Group B-Randomized Withdrawal Extension Period	Placebo-Group B-Randomized Withdrawal Extension Period	Total
Arm/Group Description		Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) for up to week 24.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) for up to week 24.	Participants in the Ixekizumab 80 mg Q4W treatment group (Lead-in) were re randomized to receive Ixekizumab 80 mg Q4W subcutaneous dose at Week 24 in the randomized withdrawal extension period.	Participants in the Ixekizumab 80 mg Q2W treatment group (Lead-in) were re randomized to receive subcutaneous dose of Ixekizumab 80 mg Q2W at Week 24 in the randomized withdrawal extension period.	Participants were re-randomized to receive subcutaneous dose of placebo at Week 24 in the randomized withdrawal extension period.	Total of all reporting groups
Overall Number of Baseline Participants		255	318	48	54	53	728
Baseline Analysis Population Description		All randomized participants from extension period (period 2).
Age, Categorical; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	255 participants	318 participants	48 participants	54 participants	53 participants	728 participants
	<=18 years	0	0	0	0	0	0
	Between 18 and 65 years	240	302	48	53	52	695
	>=65 years	15	16	0	1	1	33
Sex: Female, Male; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	255 participants	318 participants	48 participants	54 participants	53 participants	728 participants
	Female	68	95	10	14	15	202
	Male	187	223	38	40	38	526
Ethnicity (NIH/OMB); Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	255 participants	318 participants	48 participants	54 participants	53 participants	728 participants
	Hispanic or Latino	61	86	7	14	11	179
	Not Hispanic or Latino	166	204	31	35	39	475
	Unknown or Not Reported	28	28	10	5	3	74
Race (NIH/OMB); Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	255 participants	318 participants	48 participants	54 participants	53 participants	728 participants
	American Indian or Alaska Native	14	11	2	5	4	36
	Asian	54	50	15	15	13	147
	Native Hawaiian or Other Pacific Islander	0	0	0	0	0	0
	Black or African American	0	2	0	0	0	2
	White	183	247	31	31	35	527
	More than one race	3	8	0	3	1	15
	Unknown or Not Reported	1	0	0	0	0	1
Region of Enrollment; Measure Type: Count of Participants; Unit of measure: Participants	Number Analyzed	255 participants	318 participants	48 participants	54 participants	53 participants	728 participants
Argentina		11	18	1	1	2	33
Romania		1	3	0	1	0	5
Hungary		3	2	1	1	0	7
United States		14	30	1	3	2	50
Czechia		37	35	5	4	4	85
Japan		7	9	1	3	1	21
United Kingdom		4	6	0	1	0	11
Spain		5	4	0	1	0	10
Russia		16	30	6	7	6	65
Canada		3	2	1	0	2	8
Netherlands		0	2	0	0	0	2
South Korea		28	23	10	7	8	76
Austria		1	1	0	1	0	3
Taiwan		17	16	3	5	2	43
Finland		0	5	0	1	2	8
Brazil		7	16	0	0	0	23
Poland		50	67	13	7	13	150
Italy		0	1	0	0	0	1
Mexico		40	38	5	11	8	102
Israel		5	3	0	0	1	9
France		4	4	0	0	0	8
Germany		2	3	1	0	2	8

Outcome Measures

1. Primary Outcome

Title	Percentage of Participants Who do Not Experience a Flare (Combined Ixekizumab Treatment)
Description	A flare is defined as Ankylosing Spondylitis Disease Activity Score (ASDAS ≥2.1) at 2 consecutive visits, or ASDAS >3.5 at any visit during Period 2. ASDAS is a composite index to assess disease activity in AS. The parameters used for the ASDAS (with high sensitivity C-reactive protein (CRP) as acute phase reactant) are total back pain, patient global, peripheral pain/swelling, duration of morning stiffness and CRP in mg/L. The ASDAScrp is calculated with the following equation: 0.121×total back pain+0.110×patient global+0.073×peripheral pain/swelling+0.058×duration of morning stiffness+0.579×Ln(CRP+1). (CRP is in mg/liter, the range of other variables is from 0(normal) to 10(very severe); Ln represents the natural logarithm). Data from five variables combined to yield a score (0.6361 to no defined upper limit), where higher the score worse the disease activity.
Time Frame	Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the nonresponder imputation (NRI) method.

Arm/Group Title	Combined IXE	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) and every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	102	53
Measure Type: Number; Unit of Measure: Percentage of participants
	83.3	54.7

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Combined IXE, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	4.35
	Confidence Interval	(2-Sided) 95%; 2.03 to 9.35
	Estimation Comments	[Not Specified]

2. Secondary Outcome

Title	Percentage of Participants Who do Not Experience a Flare
Description	A flare is defined as Ankylosing Spondylitis Disease Activity Score (ASDAS ≥2.1) at 2 consecutive visits, or ASDAS >3.5 at any visit during Period 2. ASDAS is a composite index to assess disease activity in AS. The parameters used for the ASDAS (with high sensitivity C-reactive protein (CRP) as acute phase reactant) are total back pain, patient global, peripheral pain/swelling, duration of morning stiffness and CRP in mg/L. The ASDAScrp is calculated with the following equation: 0.121×total back pain+0.110×patient global+0.073×peripheral pain/swelling+0.058×duration of morning stiffness+0.579×Ln(CRP+1). (CRP is in mg/liter, the range of other variables is from 0(normal) to 10(very severe); Ln represents the natural logarithm). Data from five variables combined to yield a score (0.6361 to no defined upper limit), where higher the score worse the disease activity.
Time Frame	Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the nonresponder imputation (NRI) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Measure Type: Number; Unit of Measure: Percentage of participants
	83.3	83.3	54.7

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.003
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	4.28
	Confidence Interval	(2-Sided) 95%; 1.66 to 11.03
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	4.42
	Confidence Interval	(2-Sided) 95%; 1.77 to 11.02
	Estimation Comments	[Not Specified]

3. Secondary Outcome

Title	Change From Baseline in Modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS)
Description	The mSASSS is a four-point scoring system for lateral radiographs of the lumbar and cervical spine and has been shown to reliably track disease progression over time, where: 0 = normal; 1 = sclerosis, squaring or erosion; 2 = syndesmophyte; 3 = bony bridge. By the scoring system of mSASSS of the spinal x-rays, a total of 24 sites were scored on the lateral cervical and lumbar spine: the anterior corners of the vertebrae from lower border of C2 to upper border T1 (inclusive), and from lower border of T12 to upper border of S1 (inclusive). Each corner was scored from 0 to 3, resulting in a range from 0 [no change] to 72 [progression].
Time Frame	Baseline, 2 Years

Outcome Measure Data

Analysis Population Description

Ixekizumab structure population who have been treated with ixekizumab for at least 24 months.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Combined IXE
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W).	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W).	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) and two weeks (Q2W).
Overall Number of Participants Analyzed	115	115	230
Mean (Standard Deviation); Unit of Measure: Units on a Scale
	0.41 (2.102)	0.23 (1.387)	0.32 (1.779)

4. Secondary Outcome

Title	Percentage of Participants Achieving an Assessment of Spondyloarthritis International Society (ASAS)20 Response
Description	ASAS20 response is defined as a ≥20% improvement and an absolute improvement from baseline of ≥1 units (range 0 to 10) in ≥3 of 4 domains, and no worsening of ≥20% and ≥1 unit (range 0 to 10) in the remaining domain. The following ASAS domains are used: Patient Global: How active was your spondylitis on average during the last week? score ranges 0 (not active) to 10 (very active). Spinal Pain: How much Pain of your spine due to Ankylosing spondylitis? score ranges 0 (no pain) to 10 (severe pain). Bath Ankylosing Spondylitis Functional Index (BASFI): Participant asked to rate the difficulty associated with 10 individual basic functional activities. Participant response was captured using Numeric Rating Scale (NRS) (range 0 to 10) with a higher score indicating worse function. Inflammation based on mean of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Q5 & Q6 (mean of intensity & duration of stiffness): Score ranges from "0" (none) and "10" (very severe).
Time Frame	Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the nonresponder imputation (NRI) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Measure Type: Number; Unit of Measure: Percentage of participants
	81.3	81.5	50.9

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	4.51
	Confidence Interval	(2-Sided) 95%; 1.78 to 11.41
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	4.61
	Confidence Interval	(2-Sided) 95%; 1.88 to 11.31
	Estimation Comments	[Not Specified]

5. Secondary Outcome

Title	Percentage of Participants Achieving an ASAS40 Response
Description	ASAS40 is defined as a ≥40% improvement and an absolute improvement from baseline of ≥2 units (range of 0 to 10) in at least 3 of the following 4 domains without any worsening in the remaining domain. The following ASAS domains are used: Patient Global: How active was your spondylitis on average during the last week? score ranges 0 (not active) to 10 (very active). Spinal Pain: How much Pain of your spine due to Ankylosing spondylitis? score ranges 0 (no pain) to 10 (severe pain). Bath Ankylosing Spondylitis Functional Index (BASFI): Participant asked to rate the difficulty associated with 10 individual basic functional activities. Participant response was captured using Numeric Rating Scale (NRS) (range 0 to 10) with a higher score indicating worse function. Inflammation based on mean of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) Q5 & Q6 (mean of intensity & duration of stiffness): Score ranges from "0" (none) and "10" (very severe).
Time Frame	Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the nonresponder imputation (NRI) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Measure Type: Number; Unit of Measure: Percentage of Participants
	79.2	79.6	43.4

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	5.17
	Confidence Interval	(2-Sided) 95%; 2.11 to 12.69
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	5.23
	Confidence Interval	(2-Sided) 95%; 2.20 to 12.47
	Estimation Comments	[Not Specified]

6. Secondary Outcome

Title	Percentage of Participants With Change of Ankylosing Spondylitis Disease Activity Score (ASDAS) ≥1.1 Units
Description	ASDAS is a composite index to assess disease activity in AS. The parameters used for the ASDAS (with CRP as acute phase reactant) are total back pain, patient global, peripheral pain/swelling, duration of morning stiffness and CRP in mg/L. The ASDAScrp is calculated with the following equation: 0.121×total back pain+0.110×patient global+0.073×peripheral pain/swelling+0.058×duration of morning stiffness +0.579×Ln(CRP+1). (CRP is in mg/liter, the range of other variables is from 0(normal) to 10(very severe); Ln represents the natural logarithm). Data from five variables combined to yield a score (0.6361 to no defined upper limit), where higher the score worse the disease activity.
Time Frame	Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the nonresponder imputation (NRI) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Measure Type: Number; Unit of Measure: Percentage of participants
	79.2	74.1	45.3

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	4.60
	Confidence Interval	(2-Sided) 95%; 1.90 to 11.17
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.003
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	3.55
	Confidence Interval	(2-Sided) 95%; 1.56 to 8.09
	Estimation Comments	[Not Specified]

7. Secondary Outcome

Title	Percentage of Participants With Inactive Disease on the ASDAS (<1.3 Units)
Description	ASDAS is a composite index to assess disease activity in AS. The parameters used for the ASDAS (with CRP as acute phase reactant) are total back pain, patient global, peripheral pain/swelling, duration of morning stiffness and CRP in mg/L. The ASDAScrp is calculated with the following equation: 0.121×total back pain+0.110×patient global+0.073×peripheral pain/swelling+0.058×duration of morning stiffness+0.579×Ln(CRP+1). (CRP is in mg/liter, the range of other variables is from 0(normal) to 10(very severe); Ln represents the natural logarithm). Data from five variables combined to yield a score (0.6361 to no defined upper limit), where higher the score worse the disease activity.
Time Frame	Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the nonresponder imputation (NRI) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Measure Type: Number; Unit of Measure: Percentage of participants
	60.4	53.7	24.5

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	4.92
	Confidence Interval	(2-Sided) 95%; 2.07 to 11.72
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.003
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	3.61
	Confidence Interval	(2-Sided) 95%; 1.57 to 8.32
	Estimation Comments	[Not Specified]

8. Secondary Outcome

Title	Change From Baseline in the Individual Components of the ASAS Criteria
Description	Patient Global: How active was your spondylitis on average during the last week? score ranges 0 (not active) to 10 (very active). Spinal Pain: How much Pain of your spine due to Ankylosing spondylitis? score ranges 0 (no pain) to 10 (severe pain). Bath Ankylosing Spondylitis Functional Index (BASFI): Participant asked to rate the difficulty associated with 10 individual basic functional activities. Participant response was captured using Numeric Rating Scale (NRS) (range 0 to 10) with a higher score indicating worse function. Inflammation based on Q5 & Q6 mean of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (mean of intensity & duration of stiffness): Score ranges from "0" (none) and "10" (very severe). LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Least Squares Mean (Standard Error); Unit of Measure: Units on a scale
Patient Global	-5.1 (0.38)	-5.0 (0.36)	-3.0 (0.36)
Spinal Pain	-5.1 (0.39)	-4.8 (0.37)	-3.0 (0.36)
BASFI	-4.35 (0.316)	-4.19 (0.301)	-2.79 (0.301)
Inflammation	-5.20 (0.336)	-4.83 (0.319)	-3.03 (0.317)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	Patient Global
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-2.1
	Confidence Interval	(2-Sided) 95%; -3.1 to -1.1
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.51
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	Patient Global
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-2.0
	Confidence Interval	(2-Sided) 95%; -2.9 to -1.0
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.49
	Estimation Comments	[Not Specified]

Statistical Analysis 3

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	Spinal Pain
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-2.1
	Confidence Interval	(2-Sided) 95%; -3.1 to -1.0
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.51
	Estimation Comments	[Not Specified]

Statistical Analysis 4

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	Spinal Pain
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-1.8
	Confidence Interval	(2-Sided) 95%; -2.8 to -0.8
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.49
	Estimation Comments	[Not Specified]

Statistical Analysis 5

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	BASFI
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-1.55
	Confidence Interval	(2-Sided) 95%; -2.39 to -0.72
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.421
	Estimation Comments	[Not Specified]

Statistical Analysis 6

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	BASFI
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-1.40
	Confidence Interval	(2-Sided) 95%; -2.20 to -0.59
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.409
	Estimation Comments	[Not Specified]

Statistical Analysis 7

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	Inflammation
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-2.17
	Confidence Interval	(2-Sided) 95%; -3.05 to -1.28
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.448
	Estimation Comments	[Not Specified]

Statistical Analysis 8

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	Inflammation
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-1.80
	Confidence Interval	(2-Sided) 95%; -2.66 to -0.95
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.433
	Estimation Comments	[Not Specified]

9. Secondary Outcome

Title	Percentage of Participants Achieving Bath Ankylosing Spondylitis Disease Activity Index 50 (BASDAI50) Response
Description	The BASDAI is a participant-reported assessment consisting of 6 questions that relate to 5 major symptoms relevant to radiographic axial spondyloarthritis (rad-axSpA): 1) Fatigue, 2) Spinal pain, 3) Peripheral arthritis, 4) Enthesitis, 5) Intensity, and 6) Duration of morning stiffness. Participants need to score each item with a score from 0 to 10 (NRS). Total score is obtained from the average of symptom scores ranging 0 (no problem) to 10 (worst problem), with a higher score indicating more severe AS symptom. BASDAI50 represents an improvement of ≥50% of the BASDAI score from baseline.
Time Frame	Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the nonresponder imputation (NRI) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Measure Type: Number; Unit of Measure: Percentage of participants
	81.3	75.9	45.3

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	5.34
	Confidence Interval	(2-Sided) 95%; 2.13 to 13.35
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.001
	Comments	[Not Specified]
	Method	Regression, Logistic
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	Odds Ratio (OR)
	Estimated Value	4.07
	Confidence Interval	(2-Sided) 95%; 1.75 to 9.45
	Estimation Comments	[Not Specified]

10. Secondary Outcome

Title	Change From Baseline in the Measure of High Sensitivity C-Reactive Protein (CRP)
Description	High sensitivity CRP is the measure of acute phase reactant. It was measured with a high sensitivity assay at the central laboratory to help assess the effect of ixekizumab on disease activity. High sensitivity CRP is a sensitive laboratory assay for serum levels of C-Reactive Protein, which is a biomarker of inflammation. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Least Squares Mean (Standard Error); Unit of Measure: milligram per liter (mg/L)
	-12.952 (1.4666)	-11.074 (1.3861)	-5.094 (1.3696)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	<0.001
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-7.858
	Confidence Interval	(2-Sided) 95%; -11.729 to -3.987
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 1.9586
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.002
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-5.979
	Confidence Interval	(2-Sided) 95%; -9.655 to -2.304
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 1.8600
	Estimation Comments	[Not Specified]

11. Secondary Outcome

Title	Change From Baseline in Bath Ankylosing Spondylitis Metrology Index (BASMI)
Description	BASMI is a combined index comprising of the following 5 clinical measurements of spinal mobility in participants with radiographic axial spondyloarthritis (rad-axSpA).; Lateral Spinal Flexion; Tragus-to-wall distance; Lumbar Flexion (modified Schober); Maximal intermalleolar distance and; Cervical rotation. The BASMI linear result is the average of the 5 assessments and ranges from 0 to 10. The higher the BASMI score the more severe the participant's limitation of movement due to their AS. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Least Squares Mean (Standard Error); Unit of Measure: Units on a scale
	-0.69 (0.080)	-0.73 (0.075)	-0.50 (0.073)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.062
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.20
	Confidence Interval	(2-Sided) 95%; -0.40 to 0.01
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.104
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.018
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.24
	Confidence Interval	(2-Sided) 95%; -0.43 to -0.04
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.099
	Estimation Comments	[Not Specified]

12. Secondary Outcome

Title	Change From Baseline in Chest Expansion in Centimeters
Description	Chest expansion is the difference, in centimeter (cm), between the circumference of the chest in maximal inspiration and maximal expiration. While participants have their hands resting on or behind the head, the assessor will measure the chest encircled length by centimeter (cm) at the fourth intercostal level anteriorly. Two tries were recorded. The better measurement (larger difference) of 2 tries (in centimeters) was used for analyses. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Least Squares Mean (Standard Error); Unit of Measure: centimeter (cm)
	0.77 (0.256)	0.53 (0.243)	0.67 (0.236)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.757
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	0.10
	Confidence Interval	(2-Sided) 95%; -0.56 to 0.77
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.335
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.670
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.14
	Confidence Interval	(2-Sided) 95%; -0.77 to 0.50
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.322
	Estimation Comments	[Not Specified]

13. Secondary Outcome

Title	Change From Baseline in Occiput to Wall Distance
Description	The participant is to make a maximum effort to touch the head against the wall when standing with heels and back against the wall (occiput). Then the distance from occiput to wall is measured. Two tries will be recorded. The better (smaller) measurement of 2 tries (in centimeters) will be used for analyses. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Least Squares Mean (Standard Error); Unit of Measure: cm
	-0.78 (0.260)	-0.66 (0.239)	-0.38 (0.235)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.236
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.40
	Confidence Interval	(2-Sided) 95%; -1.07 to 0.27
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.338
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.373
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.28
	Confidence Interval	(2-Sided) 95%; -0.92 to 0.35
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.319
	Estimation Comments	[Not Specified]

14. Secondary Outcome

Title	Change From Baseline in Maastricht Ankylosing Spondylitis Enthesitis Score (MASES)
Description	The MASES is an index used to measure the severity of enthesitis. The MASES assesses 13 sites for enthesitis using a score of "0" for no activity or "1" for activity. Sites assessed include costochondral 1 (right/left), costochondral 7 (right/left), spinal iliaca anterior superior (right/left), crista iliaca (right/left), spina iliaca posterior (right/left), processus spinosus L5, and Achilles tendon proximal insertion (right/left). The MASES is the sum of all site scores (range 0 to 13); higher scores indicate more severe enthesitis. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B), and with Baseline MASES score >0. Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	29	36	35
Least Squares Mean (Standard Error); Unit of Measure: Units on a scale
	-3.55 (0.352)	-3.62 (0.315)	-3.48 (0.302)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.885
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.07
	Confidence Interval	(2-Sided) 95%; -0.98 to 0.85
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.459
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.735
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.14
	Confidence Interval	(2-Sided) 95%; -0.95 to 0.68
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.410
	Estimation Comments	[Not Specified]

15. Secondary Outcome

Title	Change From Baseline in Spondyloarthritis Research Consortium of Canada (SPARCC) Enthesitis Score
Description	The SPARCC enthesitis is an index used to measure the severity of enthesitis. The SPARCC assesses 16 sites for enthesitis using a score of "0" for no activity or "1" for activity. Sites assessed include Medial epicondyle (left/right [L/R]), Lateral epicondyle (L/R), Supraspinatus insertion into greater tuberosity of humerus (L/R), Greater trochanter (L/R), Quadriceps insertion into superior border of patella (L/R), Patellar ligament insertion into inferior pole of patella or tibial tubercle (L/R), Achilles tendon insertion into calcaneum (L/R), and Plantar fascia insertion into calcaneum (L/R). The SPARCC is the sum of all site scores (range 0 to 16). Higher scores indicate more severe enthesitis. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B), and with baseline SPARCC score >0. Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	22	30	30
Least Squares Mean (Standard Error); Unit of Measure: Units on a scale
	-3.23 (0.388)	-3.34 (0.338)	-2.71 (0.335)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.294
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.53
	Confidence Interval	(2-Sided) 95%; -1.53 to 0.47
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.501
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.164
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.64
	Confidence Interval	(2-Sided) 95%; -1.54 to 0.27
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.453
	Estimation Comments	[Not Specified]

16. Secondary Outcome

Title	Change From Baseline in Severity of Peripheral Arthritis by Tender Joint Count (TJC) Score of 46 Joints
Description	The number of tender and painful joints was determined by examination of 46 joints (23 joints on each side of the body). The 46 joints were assessed and classified as tender or not tender. Sum of all joints checked to be tender/painful divided by number of evaluable joints which was multiplied by 46 to obtain TJC score. The scores ranges from 0 (no tender/painful joints) to 46 (all joints tender/painful). LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B), and with baseline TJC >0. Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	27	33	23
Least Squares Mean (Standard Error); Unit of Measure: Units on a scale
	-6.1 (0.76)	-5.3 (0.74)	-4.0 (0.85)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.063
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-2.1
	Confidence Interval	(2-Sided) 95%; -4.3 to 0.1
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 1.10
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.211
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-1.3
	Confidence Interval	(2-Sided) 95%; -3.3 to 0.7
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 1.02
	Estimation Comments	[Not Specified]

17. Secondary Outcome

Title	Change From Baseline in Severity of Peripheral Arthritis by Swollen Joint Count (SJC) Score of 44 Joints
Description	The number of swollen joints was determined by examination of 44 joints (22 joints on each side of the body). The 44 joints were assessed and classified as swollen or not swollen. Sum of all joints checked to be swollen divided by number of evaluable joints which was multiplied by 44 to obtain SJC score. The SJC score ranges from 0 (no swollen joints) to 44 (all joints swollen). LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B), and with baseline SJC >0. Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	16	21	15
Least Squares Mean (Standard Error); Unit of Measure: Units on a scale
	-3.6 (0.67)	-3.9 (0.59)	-2.7 (0.73)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.334
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.9
	Confidence Interval	(2-Sided) 95%; -2.7 to 0.9
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.90
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.168
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-1.2
	Confidence Interval	(2-Sided) 95%; -3.0 to 0.5
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.88
	Estimation Comments	[Not Specified]

18. Secondary Outcome

Title	Percentage of Participants With Anterior Uveitis or Uveitis Flares
Description	Anterior uveitis is an inflammation of the middle layer of the eye. which includes the iris (colored part of the eye) and the adjacent tissue, known as the ciliary body.
Time Frame	Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B), and regardless of history of anterior uveitis.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Measure Type: Number; Unit of Measure: Percentage of Participants
	4.2	5.6	5.7

19. Secondary Outcome

Title	Change From Baseline in the Fatigue Numeric Rating Scale (NRS) Score
Description	The fatigue severity NRS is a participant administered single-item 11-point horizontal scale anchored at 0 and 10, with 0 representing "no fatigue" and 10 representing "as bad as you can imagine". Participants rate their fatigue (feeling tired or worn out) by circling the 1 number that describes their worst level of fatigue during the previous 24 hours. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Least Squares Mean (Standard Error); Unit of Measure: units on a scale
	-4.2 (0.31)	-4.3 (0.29)	-3.5 (0.28)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.100
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.7
	Confidence Interval	(2-Sided) 95%; -1.5 to 0.1
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.40
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.047
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.8
	Confidence Interval	(2-Sided) 95%; -1.5 to -0.0
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.38
	Estimation Comments	[Not Specified]

20. Secondary Outcome

Title	Change From Baseline on the Quick Inventory of Depressive Symptomatology Self-Report-16 (QIDS-SR16)
Description	The 16-item QIDS-SR16 version is a widely used validated scale designed to assess the severity of depressive symptoms. The participant was asked to rate the severity and frequency of specific symptoms present over the last 7 days. The QIDS-SR16 total scores range from 0 to 27, where higher scores indicate higher severity of symptoms. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Least Squares Mean (Standard Error); Unit of Measure: units on a scale
	-3.68 (0.362)	-3.28 (0.344)	-2.80 (0.342)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.068
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.88
	Confidence Interval	(2-Sided) 95%; -1.83 to 0.06
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.479
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.307
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	-0.48
	Confidence Interval	(2-Sided) 95%; -1.40 to 0.44
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 0.465
	Estimation Comments	[Not Specified]

21. Secondary Outcome

Title	Change From Baseline in 36-Item Short Form Health Survey (SF-36) Physical Component Summary (PCS) Score
Description	The SF-36 is a 36-item participant administered measure designed to be a short, multipurpose assessment of health in the areas of physical functioning, role - physical, role - emotional, bodily pain, vitality, social functioning, mental health, and general health. The 2 overarching domains of mental well- being and physical well-being are captured by the Mental Component Summary and Physical Component Summary scores. T-scores are used for analysis. The summary scores range from 0 to 100, with higher scores indicating better levels of function and/or better health. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Least Squares Mean (Standard Error); Unit of Measure: units on a scale
	13.2954 (1.1210)	13.1030 (1.0457)	10.6934 (1.0366)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.079
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	2.6021
	Confidence Interval	(2-Sided) 95%; -0.3011 to 5.5053
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 1.4684
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.087
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	2.4096
	Confidence Interval	(2-Sided) 95%; -0.3541 to 5.1734
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 1.3978
	Estimation Comments	[Not Specified]

22. Secondary Outcome

Title	Change From Baseline in SF-36 Mental Component Summary (MCS) Score
Description	The SF-36 is a 36-item participant administered measure designed to be a short, multipurpose assessment of health in the areas of physical functioning, role - physical, role - emotional, bodily pain, vitality, social functioning, mental health, and general health. The 2 overarching domains of mental well- being and physical well-being are captured by the Mental Component Summary and Physical Component Summary scores. T-scores are used for analysis. The summary scores range from 0 to 100, with higher scores indicating better levels of function and/or better health. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description:	Participants received 80 mg of Ixekizumab subcutaneously every four weeks (Q4W) during the randomized withdrawal extension period.	Participants received 80 mg of Ixekizumab subcutaneously every two weeks (Q2W) during the randomized withdrawal extension period.	Participants received placebo subcutaneously during the randomized withdrawal extension period.
Overall Number of Participants Analyzed	48	54	53
Least Squares Mean (Standard Error); Unit of Measure: units on a scale
	3.1766 (0.8968)	4.6404 (0.8369)	2.3396 (0.8314)

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	IXE80Q4W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.477
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	0.8370
	Confidence Interval	(2-Sided) 95%; -1.4864 to 3.1605
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 1.1752
	Estimation Comments	[Not Specified]

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	IXE80Q2W, Placebo
	Comments	[Not Specified]
	Type of Statistical Test	Superiority
	Comments	[Not Specified]
Statistical Test of Hypothesis	P-Value	0.042
	Comments	[Not Specified]
	Method	ANCOVA
	Comments	[Not Specified]
Method of Estimation	Estimation Parameter	LS Mean Difference
	Estimated Value	2.3009
	Confidence Interval	(2-Sided) 95%; 0.0880 to 4.5138
	Parameter Dispersion	Type: Standard Error of the Mean; Value: 1.1192
	Estimation Comments	[Not Specified]

23. Secondary Outcome

Title	Change From Baseline in ASAS Health Index (ASAS HI)
Description	The ASAS Health Index (ASAS HI) is a disease specific health-index instrument designed to assess the impact of interventions for SpA, including axSpA. The 17 item instrument has scores ranging from 0 (good Health) to 17 (poor Health). Each item consists of 1 question that the participant needs to respond to with either "I agree" (score 1) or "I do not agree (score 0)." A score of "1" is given where the item is affirmed, indicating adverse health. All item scores are summed to give a total score or index. LS mean was determined by ANCOVA with treatment, geographic region, originating study, baseline value and Week 24 value as fixed factors.
Time Frame	Baseline, Week 64

Outcome Measure Data

Analysis Population Description

Participants who achieved a state of sustained remission and were randomized to 40-week double-blind placebo controlled RWR period (Group B). Missing data was imputed using the modified baseline observation carried forward (mBOCF) method.

Arm/Group Title	IXE80Q4W	IXE80Q2W	Placebo
Arm/Group Description: