Inclusion Criteria:

1. Patients must have histologically or cytologically confirmed newly diagnosed systemic anaplastic large cell lymphoma. Tissue should be available for the determination of ALK status prior to study entry (t2;5, ALK-NPM translocation).
2. Patients must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded) as >/= 20 mm with conventional techniques or as >/= 10 mm with spiral CT scan.
3. Prior steroids or topical treatments are allowed. Patients who are on chronic steroid therapy may receive concomitant steroids provided they have been on a stable dosage for at least 3 months prior to enrollment.
4. Age >/= 18 years. Because no dosing or adverse event data are currently available on the use of SGN-30 in patients <18 years of age, children are excluded from this study, but may be eligible for future pediatric phase 2 combination trials.
5. Eastern Cooperative Oncology Group (ECOG) performance status </= 1 (Karnofsky >/= 70%).
6. Patients must have normal organ and marrow function as defined below: leukocytes >/= 3,000/mcL; Absolute neutrophile count >/= 1,500/mcL; platelets >/= 100,000/mcL unless due to lymphoma (i.e. splenomegaly and/or bone marrow involvement); total bilirubin </= 1.5 times Upper limit of normal; AST(SGOT)/ALT(SGPT) </= 2.5 x institutional upper limit of normal; creatinine </=1.5 times upper limit of normal unless due to lymphoma OR creatinine clearance >/= 60 mL/min for patients with creatinine levels above institutional normal.
7. Cardiac ejection fraction of 50% or higher.
8. The effects of SGN-30 and CHOP on the developing human fetus at the recommended therapeutic dose are unknown. For this reason women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
9. Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

1. Prior chemotherapy for ALCL.
2. Patients may not be receiving any other investigational agents.
3. Patients with known brain metastases should be excluded from this clinical trial because of their poor prognosis. Patients with brain metastases often develop progressive neurologic dysfunction that may confound the evaluation of neurologic toxicities and other adverse events.
4. History of allergic reactions attributed to compounds of similar chemical or biologic composition to SGN-30.
5. Patients with rapidly progressing disease or bulky disease defined as a mass of > 7 cm in largest diameter.
6. Uncontrolled intercurrent illness including but not limited to: ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
7. Pregnant women are excluded from this study because SGN-30 is an agent with the potential for teratogenic or abortifacient effects. Because there is an unknown, but potential risk for adverse events in nursing infants secondary to treatment of the mother with SGN-30, breastfeeding should be discontinued if the mother is treated with SGN-30. These potential risks may also apply to other agents used in this study.
8. HIV-positive patients on combination antiretroviral therapy are ineligible because of the potential for pharmacokinetic interactions with SGN-30. In addition, these patients are at increased risk of lethal infections when treated with marrow-suppressive therapy. Appropriate studies will be undertaken in patients receiving combination antiretroviral therapy when indicated.
9. Concurrent or previous malignancy with <90% probability of survival at 5 years.
10. Patients with primary cutaneous ALCL (only skin involvement).