Study to Investigate the Safety and Tolerability of REGN1979 in Patients With CD20+ B-Cell Malignancies

Key Inclusion Criteria:

1. Have documented CD20+ B-cell malignancy, with active disease not responsive to prior therapy, for whom no standard of care options exists, and for whom treatment with an anti-CD20 antibody may be appropriate.

2. Patients with NHL must have had prior treatment with an anti-CD20 antibody therapy. Patients with CLL are not required to have received prior treatment with an anti-CD20 antibody therapy, provided the patient has failed either a BTK inhibitor or PI3K inhibitor and the treating physician deems it appropriate for the patient to be entered into a phase 1 trial.

   • For inclusion in the FL grade 1-3a expansion cohort, patients must have received at least 2 prior lines of systemic therapy, including an anti-CD20 antibody and an alkylating agent.
   • For the inclusion in the disease-specific expansion cohort enrolling DLBCL patients after failure of CAR-T therapy, the patient must have recovered from the toxicities of the lymphodepletion therapy and CAR-T infusion.
3. Must have at least one bi-dimensionally measurable lesion ≥1.5 cm) documented by CT or MRI scan.
4. Eastern Cooperative Oncology Group (ECOG) performance status ≤1
5. Life expectancy of at least 6 months

6. Adequate bone marrow function documented by:

   1. Platelet counts ≥75 x 10^9/L
   2. Hb level ≥9 g/dL
   3. Absolute neutrophil count (ANC) ≥1 x 10^9/L

7. Adequate organ function documented by:

   1. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5 X ULN
   2. Total bilirubin ≤1.5 X ULN
   3. Calculated creatinine clearance by Cockcroft-Gault ≥50 mL/min (patients with borderline creatinine clearance by Cockcroft-Gault may be considered for enrollment if a measured creatinine clearance (based on 24-hour urine or other reliable method) is ≥50 mL/min)
8. Willing and able to comply with clinic visits and study-related procedures
9. Provide signed informed consent

Key Exclusion Criteria:

1. Primary central nervous system (CNS) lymphoma or known or suspected CNS involvement by non-primary CNS NHL
2. History of or current relevant CNS pathology
3. Allogeneic stem cell transplantation
4. Infection with human immunodeficiency virus (HIV) or chronic infection with hepatitis B virus (HBV) or hepatitis C virus (HCV). Patients with hepatitis B (HepBsAg+) who have controlled infection (serum hepatitis B virus DNA that is below the limit of detection AND receiving anti-viral therapy for hepatitis B) are permitted upon consultation with the physician managing the infection.
5. Known hypersensitivity to both allopurinol and rasburicase
6. History of hypersensitivity to any compound in the tetracycline antibiotics group

The information provided above is not intended to contain all considerations relevant to potential participation in a clinical trial therefore not all inclusion/ exclusion criteria are listed.