A Multi-Center, Open Label, Phase I/II Study to Assess the Safety and Efficacy of Tenalisib Given in Combination with Romidepsin in Patients with Relapsed/Refractory T-Cell Lymphoma
Authors: Iyer Swami P. , Huen Auris , Haverkos Bradley , Ai Weiyun Z. , Okada Craig , Kuzel Timothy M. , Lechowicz Mary Jo , Alderuccio Juan Pablo , Mohrbacher Ann , Stevens Don A. , Wilcox Ryan A. , Feldman Tatyana A. , Sundaram Suchitra , Jagadeesh Deepa , Reddy Nishitha , Routhu Kasi Viswanath , Barde Prajak , Nair Ajit Mohanchandran 
Published: November 2020

Background: T cell lymphomas (TCL) have been known to exhibit epigenetic dysregulation and aberrant cell signaling. Tenalisib (RP6530), a highly selective PI3K δ/γ+SIK3 inhibitor has shown clinically promising activity as a single agent in TCL with a differentiated and favorable safety profile. In vitro studies in TCL cell lines showed increased apoptosis when tenalisib was combined with romidepsin (Rhizen data on file). A Phase I/II study of tenalisib in combination with romidepsin was designed to assess safety, pharmacokinetics and efficacy in relapsed/refractory TCL (NCT03770000).
Methods: This is a multi-center, open label, Phase I/II study in patients with T cell lymphoma (PTCL and CTCL). The Phase I is a 3+3 dose escalation study to determine the MTD/optimal dose. The Phase II is an expansion cohort at the MTD/optimal dose of the combination.
Tenalisib was administered orally at doses of 400, 600 and 800 mg BID in combination with romidepsin (12 &14 mg/m2, Q3W). The objectives of the study are to establish safety, MTD/optimal dose, pharmacokinetics and anti-tumor activity of the combination. We report the dose escalation results and preliminary data from the expansion cohorts.
Results: A total 15 patients were enrolled between July 24, 2019 and July 20, 2020. Baseline demographics are presented in Table 1. Patients had a median of 3 (range; 1-17) prior treatments and 11 (73%) were refractory to their last therapy. About 67% (6/9) of CTCL patients had prior mogamulizumab therapy. No DLT was reported in the dose escalation phase and Tenalisib 800 mg BID+ Romidepsin 14 mg/m2, Q3W was considered as the optimal dose for expansion cohorts. PK analysis showed linear and dose-dependent kinetics for tenalisib. Co-administration of romidepsin along with tenalisib did not significantly alter the mutual PK of either agents.
Fifteen patients were assessed for safety. Most common treatment emergent adverse events of any grade were nausea (33%), thrombocytopenia (33%) and fatigue (27%). Related ≥ Grade 3 AEs were seen in 5 (33%) patients. These included thrombocytopenia (7%), atrial fibrillation (7%) and pyrexia (7%) which were related to romidepsin while anemia (7%) neutropenia (7%) and rash (7%) were considered related to the combination. There were no instances of transaminitis or colitis. None of the TEAEs led to study discontinuation.
Patients from the dose escalation cohorts (n=9) were evaluated for response. Three patients (3/9) showed complete response (CR), 4 patients (4/9) showed stable disease (SD) while 2 patients (2/9) had progressive disease (PD). Out of the three responders, two were PTCL (AITL) patients, one of which is planned for transplantation, while the third patient was a CTCL (Sezary syndrome) patient who had progressed on prior mogamulizumab therapy. This patient showed rapid reduction of Sezary cell count after 2 cycles of treatment.
Three patients (2 CR, 1 SD) are currently ongoing with a median duration of response being 9.0 (range; 7.6-10.5+) months. The expansion cohort has 6 patients and is currently enrolling.
Conclusions: The combination of tenalisib and romidepsin demonstrates a favorable safety profile and promising indicators of combined anti-tumour activity in patients with R/R TCL. The expansion cohort in CTCL and PTCL is currently underway to validate these encouraging early results. Updated results will be presented during the ASH meeting.

Disclosures
Iyer: Afffimed: Research Funding; Rhizen: Research Funding; Seattle Genetics, Inc.: Research Funding; Curio Biosciences: Honoraria; Trillium: Research Funding; Daiichi Sankyo: Consultancy; Legend Biotech: Consultancy; Target Oncology: Honoraria; Spectrum: Research Funding; Merck: Research Funding; CRISPR: Research Funding. Huen:Seattle Genetics: Consultancy, Research Funding; Kyowa Kirin: Consultancy, Research Funding; Rhizen: Research Funding; Glaxo Smith Kline: Research Funding; Galderma: Research Funding; Miragen: Research Funding; Helsinn: Consultancy; Medivir: Research Funding. Haverkos:Viracta THerapeutics: Consultancy. Ai:ADC Therapeutics, Kymera: Membership on an entity's Board of Directors or advisory committees; Nurix Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kuzel:Eselixis, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genomic Health: Honoraria; Sanofi/Genzyme: Honoraria; Bioarray: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Marck: Membership on an entity's Board of Directors or advisory committees; Tyme: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cardinal Health: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Alderuccio:ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Inovio Pharmaceuticals: Other: Family member; Foundation Medicine: Other: Family member; Puma Biotechnology: Other: Family member; Forma Therapeutics: Other: Family member; Agios Pharmaceuticals: Other: Family member; Oncinfo: Honoraria; OncLive: Honoraria. Stevens:Amgen, MorphoSys: Consultancy. Feldman:Viracta: Research Funding; Portola: Research Funding; Janssen: Speakers Bureau; AstraZeneca: Consultancy; Trillium: Research Funding; Amgen: Research Funding; Pfizer: Research Funding; Kyowa Kirin: Consultancy, Research Funding; Cell Medica: Research Funding; Rhizen: Research Funding; Corvus: Research Funding; BMS: Consultancy, Honoraria, Research Funding; Kite: Honoraria, Other: Travel expenses, Speakers Bureau; Celgene: Honoraria, Research Funding; Seattle Genetics, Inc.: Consultancy, Honoraria, Other: Travel expenses, Research Funding, Speakers Bureau; Takeda: Honoraria, Other: Travel expenses; Pharmacyclics: Honoraria, Other, Speakers Bureau; Abbvie: Honoraria; Bayer: Consultancy, Honoraria; Eisai: Research Funding. Jagadeesh:Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Regeneron: Research Funding; Verastem: Membership on an entity's Board of Directors or advisory committees; Debiopharm Group: Research Funding; MEI Pharma: Research Funding. Reddy:KITE Pharma, Abbvie, BMS, Celgene: Consultancy; Genentech, BMS: Research Funding. Routhu:Rhizen Pharmaceuticals S.A&gt;.: Current Employment. Barde:Rhizen Pharmaceuticals S.A: Current Employment. Nair:Rhizen Pharmaceuticals S.A.: Current Employment.