Analysis Of Patients With Common Peripheral T-Cell Lymphoma Subtypes From A Phase 2 Study Of Romidepsin In Relapsed Or Refractory Peripheral T-Cell Lymphoma

Abstract Abstract 591FN2 Background: Romidepsin is a potent class 1 selective histone deacetylase inhibitor approved by the US Food and Drug Administration for treatment of patients with cutaneous T-cell lymphoma who have received at least 1 prior systemic therapy and patients with peripheral T-cell lymphoma (PTCL) who have received at least 1 prior therapy. Approval for use in patients with PTCL was based in part on results from the phase 2, single-arm, open-label registration study GPI-06-0002, which demonstrated clinical benefit and tolerability of romidepsin in patients with recurrent or refractory PTCL. The aim of this subanalysis was to evaluate the efficacy and safety of romidepsin on GPI-06-0002 in the three major subtypes of PTCL: PTCL not otherwise specified (NOS), angioimmunoblastic T-cell lymphoma (AITL), and anaplastic lymphoma kinase-1–negative anaplastic large cell lymphoma (ALK-1–negative ALCL). Methods: Patients with histologically confirmed PTCL who failed or were refractory to ≥ 1 prior systemic therapy received romidepsin 14 mg/m2 as a 4-hour intravenous infusion on days 1, 8, and 15 every 28 days for up to 6 cycles; treatment could be extended for patients achieving stable disease (SD) or better. The primary efficacy endpoint was rate of confirmed/unconfirmed complete response (CR/CRu); secondary endpoints were objective response rate (ORR: CR/CRu + partial response [PR]) and duration of response (DOR). Because of the aggressive nature of PTCL, prolonged disease stabilization can provide patient benefit, thus ORR + SD ≥ 90 days was used as an overall measure of disease control. Efficacy assessments were made by an Independent Review Committee (IRC) and consisted of an initial radiographic review of images (CT, MRI) followed by an overall clinical assessment based on the radiology evaluations, photographs, and relevant clinical parameters. Results: Of the 131 enrolled patients, 130 patients had histologically confirmed PTCL by central review, with a median of 2 (range 1–8) prior systemic therapies for PTCL. The majority of patients (117/130) had PTCL-NOS (n = 69), AITL (n = 27), or ALK-1–negative ALCL (n = 21). Responses assessed by the IRC and the most common grade ≥ 3 adverse events (AEs) for the 3 major subtypes are noted in the table. ORR was similar across subtypes, including 30% in patients with AITL, with 19% CR/CRu. With a median duration of follow-up of 10.9 months, the median DOR for all responders was 17 months for patients with PTCL-NOS and 12 months for patients with ALK-1–negative ALCL. Median DOR was not yet evaluable for patients with AITL, who had the longest DOR ongoing at 34 months. Overall, 66% of patients experienced at least 1 grade ≥ 3 AE; 78% in patients with AITL, 67% in patients with PTCL-NOS, and 48% in patients with ALK-1–negative AITL. Eighteen of 117 patients (15%) experienced grade ≥ 3 infection; however infections led to discontinuation in only 4 of 117 patients (3%), 1 with PTCL-NOS and 3 with ALK-1–negative ALCL. Infection rates were higher in patients whose disease had bone marrow involvement or who had received prior monoclonal antibody therapy. Conclusions: Similar CR/CRu rates were observed across the 3 major PTCL subtypes (PTCL-NOS, AITL, and ALK-1–negative ALCL). Romidepsin induced durable responses in patients with the major subtypes of PTCL, with nearly half (46%) of these patients experiencing disease control. These data support the use of single-agent romidepsin to treat relapsed or refractory PTCL-NOS, AITL, and ALK-1–negative ALCL as well as the development of romidepsin-based combination regimens and front-line therapies in these histologies Disclosures: Coiffier: Celgene: Consultancy; Gloucester: Consultancy. Pro:Celgene: Consultancy, Honoraria. Prince:Celgene: Honoraria, Research Funding. Foss:Celgene: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Consultancy. Sokol:Celgene: Consultancy, Speakers Bureau; Gloucester: Research Funding. Caballero:Celgene: Speakers Bureau; Roche: Speakers Bureau; Mundipharma: Speakers Bureau; Pfizer: Speakers Bureau. Morschhauser:Bayer: Honoraria; Roche: Consultancy, Honoraria. Pinter-Brown:Celgene: Consultancy; Allos: Consultancy; Merck: Consultancy; Spectrum: Honoraria; Genetech: Speakers Bureau. Padmanabhan:Celgene: Consultancy, Honoraria. Shustov:Celgene: Research Funding, Speakers Bureau. Nichols:Celgene: Employment, Equity Ownership. Carroll:Celgene: Employment, Equity Ownership. Balser:Celgene: Contracted Consultancy. Horwitz:Celgene: Consultancy, Research Funding; Allos: Consultancy, Research Funding; Seattle Genetics: Consultancy; Novartis: Consultancy; Merck: Honoraria; Millennium: Consultancy; Genzyme: Research Funding.