Oña, Raquel de

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.

Background Tipifarnib is a potent and selective inhibitor of the enzyme farnesyltransferase (FT). FT catalyzes post-translational attachment of farnesyl groups required for localization of signaling molecules to the inner cell membrane. CXCL12 is a ligand for CXCR4 that is essential for T cell homing to lymphoid organs and the bone marrow, and for the maintenance of immune cell progenitors. We have previously shown that FT inhibition by tipifarnib downregulates CXCL12 secretion. Herein we report preliminary efficacy, safety and biomarker data from a Phase 2 study of tipifarnib in angioimmunoblastic T-cell lymphoma (AITL) and CXCL12+ peripheral T-cell lymphoma (PTCL) patients (pts). Methods This Phase 2 study (NCT02464228) is a multi-institutional, single-arm, open-label trial initially designed as a two-stage (11+7 pts) design to determine the efficacy, safety and biomarkers of tipifarnib in pts with relapsed/refractory (R/R) PTCL age >/=18 years and a performance status of 0-2. Based on initial findings, the study was amended to include a cohort of AITL (n=12) and PTCL (n=12) pts with the CXCL12 rs2839695 A/A genotype (wt CXCL12 3'UTR cohort). Pts received tipifarnib 300 mg administered orally twice daily on days 1-21 of 28-day treatment cycles until progression of disease (PD) or unacceptable toxicity. The primary endpoint of the study is overall response rate (ORR). Tumor Whole Exon Sequencing (WES) was generated by NGS and gene expression data generated by RNA Seq. Ancillary studies also investigated the prognostic value of CXCL12 expression in pts who received standard of care treatment. Results As of 24 May 2019, 50 PTCL pts (23 AITL, 25 PTCL-NOS, 1 ALK- ALCL, 1 gamma-delta TCL) have been treated with tipifarnib, 19 pts in stages 1 and 2, and 31 pts in the ongoing AITL histology and wt CXCL12 3'UTR cohorts. Median number of prior treatment regimens was 3; 19 pts had a prior stem cell transplant. All pts (n=48 with available safety data) had at least one treatment-emergent adverse event (TEAE); 42 (88%) had at least 1 study drug-related TEAE and 13 (27%) at least 1 drug related SAE. The most frequently observed drug-related TEAEs of Grade >3 occurring in 10% or more of pts were blood and lymphatic system disorders, including neutropenia (40%), thrombocytopenia (33%), leukopenia (25%), anemia and febrile neutropenia (19% each). There have been 14 deaths on study; one related to study drug (lung infection). Of 18 evaluable pts enrolled in Stages 1 and 2 of the trial, 3 partial responses (PR), 2 of them in pts with AITL histology, and 5 best responses of stable disease (SD) were observed. In the AITL cohort (11 evaluable of 16 pts enrolled), a 45% ORR and 73% clinical benefit rate (CBR; 3 CR, 2 PR and 3 SD) was observed. In the wt CXCL12 3'UTR cohort (n=12 evaluable pts), a 42% ORR was observed (3 CR, 2 PR), with 2 of the 3 CRs observed in patients of AITL histology (n=4). A total of 23 AITL subjects were enrolled in the overall study of whom 16 had WES data. A strong association with the activity of tipifarnib was observed in 8 of the 16 (50%) carrying KIR3DL2 gene variants C336R/Q386E: 50% CR rate, 75% ORR, 100% clinical benefit rate. These tumors expressed also very low levels of CXCL5, a ligand for CXCR2, that may mediate resistance to tipifarnib. High Allele Frequency of KIR3DL2 variants predicted CR to tipifarnib treatment (ROC AUC=0.94, p<0.0001) and AITL patients carrying KIR3DL2 gene variants experienced a better outcome with tipifarnib treatment than with prior SOC treatment. While AITL tumors expressed high levels of CXCL12 and responded to tipifarnib, a trend for poor prognosis (22 vs 40 months median OS from diagnosis, HR=1.8, p=0.09) was observed in a series of 50 PTCL subjects treated with SOC therapy. Fifty percent of AITL and 35% of non-AITL samples overexpressed CXCL12. Conclusion The AITL and wt CXCL12 3'UTR cohorts met pre-specified statistical hypotheses supporting proof-of-concept for tipifarnib in PTCL. AITL histology, KIR3DL2 and CXCL12 genotype provided robust tools for the selection/stratification of PTCL subjects treated with tipifarnib. Extended enrollment of AITL patients continues and an update on enrollment and outcomes will be provided at the time of the presentation. Disclosures Sokol: EUSA: Consultancy. Foss:Mallinckrodt: Consultancy; Eisai: Consultancy; Spectrum: Other: fees for non-CME/CE services ; Acrotech: Consultancy; Seattle Genetics: Consultancy, Other: fees for non-CME/CE services ; miRagen: Consultancy. Kim:Donga: Research Funding; Celltrion: Research Funding; J&J: Research Funding; Roche: Research Funding; Kyowa-Kirin: Research Funding; Novartis: Research Funding; Mundipharma: Research Funding. Jacobsen:Kura Oncology: Research Funding. Advani:Kyowa Kirin Pharmaceutical Developments, Inc.: Consultancy; Kura: Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Research Funding; Agensys: Research Funding; Stanford University: Employment, Equity Ownership; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Celmed: Consultancy, Membership on an entity's Board of Directors or advisory committees; Forty-Seven: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cell Medica, Ltd: Consultancy; Gilead Sciences, Inc./Kite Pharma, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Infinity Pharma: Research Funding; Millennium: Research Funding. Roncero:Kura Oncology: Research Funding. Terol:Janssen: Consultancy, Research Funding; Roche: Consultancy; Gilead: Research Funding; Astra Zeneca: Consultancy; Abbvie: Consultancy. Domingo-Domenech:Bristol-Myers Squibb: Other: Travel expenses; Roche: Other: Travel expenses; Seattle Genetics: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses. Piris:Millenium/Takeda: Membership on an entity's Board of Directors or advisory committees, Other: Lecture Fees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jansen: Membership on an entity's Board of Directors or advisory committees, Other: Lecture Fees; Nanostring: Membership on an entity's Board of Directors or advisory committees; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees; Kura: Research Funding. Rodriguez:Kura Oncology: Research Funding. Bolognese:Kura Oncology: Consultancy. Kessler:Kura Oncology: Employment. Mishra:Kura Oncology: Employment. Curry:Kura Oncology: Employment. Kurman:Kura Oncology: Employment. Scholz:Kura Oncology: Employment, Equity Ownership, Patents & Royalties. Gualberto:Kura Oncology: Employment, Equity Ownership, Patents & Royalties.