Bendris, Nawal

Abstract A phase 2, international, open-label, nonrandomized, single-arm trial was conducted to evaluate the efficacy and safety of tipifarnib, a farnesyltransferase inhibitor, as monotherapy for relapsed/refractory peripheral T-cell lymphoma (PTCL) and to evaluate tumor mutation profile as a biomarker of response. Adults with relapsed/refractory PTCL received tipifarnib 300 mg orally twice daily for 21 days in a 28-day cycle. The primary end point was objective response rate (ORR); secondary end points included ORR, progression-free survival (PFS), duration of response (DOR), and adverse events (AEs) in specific subtypes. Sixty-five patients with PTCL were enrolled: n = 38 angioimmunoblastic T-cell lymphoma (AITL), n = 25 PTCL not otherwise specified, and n = 2 other T-cell lymphomas. The ORR was 39.7% (95% confidence interval [CI], 28.1-52.5) in all patients and 56.3% (95% CI, 39.3-71.8) for AITL. Median PFS was 3.5 months overall (954% CI, 2.1-4.4), and 3.6 months (95% CI, 1.9-8.3) for AITL. Median DOR was 3.7 months (95% CI, 2.0-15.3), and greatest in patients with AITL (7.8 months; 95% CI, 2.0-16.3). The median overall survival was 32.8 months (95% CI, 14.4 to not applicable). Tipifarnib-related hematologic AEs were manageable and included neutropenia (43.1%), thrombocytopenia (36.9%), and anemia (30.8%); other tipifarnib-related AEs included nausea (29.2%) and diarrhea (27.7%). One treatment-related death occurred. Mutations in RhoA, DNMT3A, and IDH2 were seen in 60%, 33%, and 27%, respectively, in the AITL tipifarnib responder group vs 36%, 9%, and 9% in the nonresponder group. Tipifarnib monotherapy demonstrated encouraging clinical activity in heavily pretreated relapsed/refractory PTCL, especially in AITL, with a manageable safety profile. This trial was registered at www.ClinicalTrials.gov as #NCT02464228.

Abstract The T-cell non-Hodgkin lymphomas continue to be an area of unmet need for new therapies that offer novel mechanisms of action. Tipifarnib is a potent and selective inhibitor of the enzyme farnesyltransferase (FT). Tipifarnib inhibits farnesylation of key regulatory proteins involved in CXCL12 production (Gualberto et al, EHA 2019). CXCL12 is a chemokine that is essential for T-cell homing to lymphoid organs and bone marrow, and for the maintenance of immune cell progenitors via its receptor CXCR4 (Susek et al, Front Immunology, 2018). Angioimmunoblastic T-cell lymphoma (AITL) is associated with high levels of CXCL12 expression, which is also a negative prognostic factor (Witzig et al, Blood, 2019). Additionally, Peripheral T-Cell lymphoma Not Otherwise Specified (PTCL-NOS) patients with the CXCL12 rs2839695 A/A wildtype genotype (PTCL-CXCL12+) have also been found to have elevated levels of CXCL12. Therefore, there is strong rationale for targeting these subsets of PTCL with tipifarnib. This Phase 2 study (NCT02464228) was a multi-institutional, single-arm, open-label trial determining the efficacy, safety, and potential predictive biomarkers for tipifarnib in adult patients with relapsed or refractory (R/R) PTCL. Patients received tipifarnib 300 mg orally twice daily on Days 1-21 of 28-day treatment cycles until progression of disease or unacceptable toxicity. The primary objective of the study was to determine the antitumor activity by overall response rate (ORR) per Lugano Classification. Secondary objectives included safety, duration of response (DoR) and progression-free survival (PFS), and exploratory analyses included overall survival (OS) and identification of potential biomarkers associated with tipifarnib activity. Sixty-five R/R PTCL patients (38 AITL, 14 PTCL-NOS, 11 PTCL-CXCL12+, 2 other (1 ALCL-ALK negative, 1 PTCL-subtype not specified) were treated with tipifarnib. The population was heavily pretreated with a median of 3 prior regimens (range 1-8). All patients had at least one treatment-emergent adverse event (TEAE); most patients (87.7%) had at least one treatment-related TEAE, and 18 (27.7%) patients had at least one treatment-related serious TEAE. The most frequently observed (≥20%) treatment-related TEAEs (all grades) were hematological (neutropenia, thrombocytopenia, anemia,) and gastrointestinal (nausea, diarrhea), as well as fatigue, which is consistent with the known safety profile of tipifarnib. Fifty-eight patients were efficacy evaluable and had an associated ORR of 39.7% (23/58) with most responses observed in the AITL and PTCL-CXCL12+ cohorts. In the 32 patients with AITL, the ORR was 56.3% (18/32), including 9 complete responses (CR) and 9 partial responses (PR). In the 10 patients with PTCL-CXCL12+, the ORR was 40.0% (4/10), including 1 CR and 3 PR. The median OS for patients with AITL was 32.8 months, and the median OS had not been reached for patients with PTCL-CXCL12+. Previously, a strong association between KIR3DL2 C336R/Q386E mutation and the activity of tipifarnib was observed and reported in AITL patients (Witzig et al, EHA 2020). Extensive gene expression and gene variant analyses of samples from the study population is currently ongoing to evaluate this correlation and explore other potential predictors of response. Final data will be presented at the time of the conference. Overall, the results from this Phase 2 study with tipifarnib demonstrated very encouraging efficacy in patients with CXCL12-expressing subtypes of PTCL (AITL and PTCL-CXCL12+) and showed a tolerable safety profile. Disclosures Witzig: Karyopharm Therapeutics, Abbvie/Genentech, Seattle Genetics, Celgene/BMS, Incyte, Epizyme, Cellectar, Tessa Therapeutics, Portola Pharmaceuticals, MorphoSys, ADC Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene/BMS, Acerta Pharma, Kura Oncology, Acrotech Biopharma, Karyopharm Therapeutics: Research Funding. Sokol: Dren Bio: Membership on an entity's Board of Directors or advisory committees; Kyowa-Kirin: Membership on an entity's Board of Directors or advisory committees. Kim: IGM Biosciences: Research Funding; Kyowa Kirin: Research Funding; Roche: Research Funding; Sanofi: Research Funding; Celltrion: Research Funding; Dong-A Pharmaceutical: Research Funding; Johnson & Johnson: Research Funding; Eisai: Research Funding. de la Cruz Vicente: Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eusapharma: Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Advani: Astellas/Agensys: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Bristol Myer Squibb: Membership on an entity's Board of Directors or advisory committees; Cell Medica: Membership on an entity's Board of Directors or advisory committees; Forty Seven: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genetech Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceutical: Research Funding; Juno: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Kura: Research Funding; Kyowa: Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; Millenium: Research Funding; Pharmacyclics: Consultancy, Research Funding; Portola Pharmaceuticals: Consultancy; Regeneron: Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees. Marin Niebla: Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kiowa Kirin: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BeiGene: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Speakers Bureau; Amgen: Speakers Bureau. Terol: BMS: Consultancy; Takeda: Membership on an entity's Board of Directors or advisory committees, Other: Travel; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel; Hospital Clinico Valencia: Current Employment; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Research Funding; Roche: Consultancy; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: Travel, Research Funding. Eva: Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Bendris: Kura Oncology: Current Employment, Current equity holder in publicly-traded company. Ahsan: Gilead: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Kura Oncology: Current Employment, Current equity holder in publicly-traded company. Leoni: Kura Oncology: Current Employment. Foss: Daiichi Sankyo: Honoraria; Mallinckrodt: Honoraria; Acrotech: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Speakers Bureau; Kyowa: Honoraria; Kura: Honoraria.