A phase Ib trial of lenvatinib (LEN) plus pembrolizumab (PEMBRO) in unresectable hepatocellular carcinoma (uHCC): Updated results

Background LEN is a multikinase inhibitor of VEGFR 1–3, FGFR 1–4, PDGFRα, RET, and KIT. PEMBRO is an anti-PD-1 monoclonal antibody. LEN monotherapy is approved for first-line treatment of uHCC. PEMBRO monotherapy has shown significant efficacy in the second-line treatment of HCC. We report updated results from a phase 1b trial of LEN + PEMBRO in uHCC. Methods In this open-label, phase 1b study of LEN + PEMBRO in uHCC, 104 patients (pts) with BCLC stage B (not amenable for transarterial chemoembolization) or C, Child-Pugh class A, and ECOG PS≤1 received LEN (body wt≥60kg: 12mg/day; <60kg: 8mg/day QD) and PEMBRO (200mg IV Q3W). Primary endpoints were safety (DLT part) and efficacy (expansion part; objective response rate [ORR] and duration of response [DOR]). Investigators performed tumor assessments using modified RECIST for HCC. No dose-limiting toxicities (DLTs) were reported in the DLT part (n=6). Enrollment was expanded to approximately 100 pts (expansion part). Recruitment (N=104) was completed April 2019. We present results for the first 67 pts enrolled by December 31, 2018. Results Pts received LEN + PEMBRO (DLT-evaluation part, n=6; expansion part, n=61). At data cutoff (June 30, 2019), 34 (50.7%) pts remained on study treatment; median duration of follow-up was 11.7 months (95% CI, 7.8-17.6). Serious adverse events occurred in 42 (62.7%) pts; no new safety signals emerged. Updated safety data will be provided. ORR (including unconfirmed responses) was 44.8% (Table) and compared favorably with LEN arm of REFLECT trial (24.1%; Kudo M. Lancet. 2018). Median DOR was 18.7 months (95% CI, 6.9-NE). Conclusions LEN + PEMBRO showed promising antitumor activity and an acceptable safety profile in pts with uHCC. Blinded independent central review is in progress. A phase 3 trial (LEAP-002; NCT03713593) is ongoing to assess LEN + PEMBRO vs LEN alone as first-line therapy for pts with uHCC. Table 747P Table Response Parameter, n (%) LEN + PEMBRO (n=67) mRECIST Per Investigator ORR (CR + PR + unconfirmed PR or CR) a Best Overall Response CR. PR a Stable disease Progressive disease Unknown/not evaluable 30 (44.8) 4 (6.0) 26 (38.8) 25 (37.3) 6 (9.0) 6 (9.0) a Includes unconfirmed partial responses (2 patients). CR, complete response; (m)RECIST, (modified) Response Evaluation Criteria In Solid Tumors [Lencioni et al. Semin Liver Dis. 2010;30:52-60]; ORR, objective response rate; PR, partial response. Clinical trial identification NCT03006926; Release date: December 30, 2016. Editorial acknowledgement Medical writing support was provided by April Suriano, PhD, of Oxford PharmaGenesis, Newtown, PA, USA and was funded by Eisai Inc. Legal entity responsible for the study Eisai Inc. Funding Eisai Inc. and Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. Disclosure J. Llovet: Advisory / Consultancy, Research grant / Funding (self): Bayer; Advisory / Consultancy, Research grant / Funding (self): Eisai; Advisory / Consultancy, Research grant / Funding (self): Bristol-Myers Squibb; Advisory / Consultancy, Research grant / Funding (self): Ipsen; Advisory / Consultancy: Eli Lilly; Advisory / Consultancy: Celsion Corporation; Advisory / Consultancy: Exelixis; Advisory / Consultancy: Merck; Advisory / Consultancy: Glycotest; Advisory / Consultancy: Navigant; Advisory / Consultancy: Leerink Swann LLC; Advisory / Consultancy: Midatech Ltd; Advisory / Consultancy: Fortess Biotech; Advisory / Consultancy: Sprink Pharmaceuticals; Advisory / Consultancy: Nucleix; Advisory / Consultancy: Can-Fite Biopharma. K.V. Shepard: Full / Part-time employment: Eisai Inc. R.S. Finn: Advisory / Consultancy, Research grant / Funding (institution): Bayer; Advisory / Consultancy, Research grant / Funding (institution): Bristol-Myers Squibb; Advisory / Consultancy, Research grant / Funding (institution): Eisai; Advisory / Consultancy: Genentech/Roche; Advisory / Consultancy, Research grant / Funding (institution): Lilly; Advisory / Consultancy, Research grant / Funding (institution): Merck; Advisory / Consultancy, Research grant / Funding (institution): Novartis; Advisory / Consultancy, Research grant / Funding (institution): Pfizer. M. Ikeda: Honoraria (self): Abbott, Bayer, Bristol-Myers Squibb, Dainippon Sumitomo Pharma, Eisai, Lilly, Nobelpharma, Novartis, Otsuka, Taiho Pharmaceutical, Teijin Pharma, Yakult Honsha; Advisory / Consultancy: Bayer, Daiichi Sankyo, Eisai, Kyowa Hakko Kirin, MSD, NanoCarrier, Novartis, Shire, Teijin Pharma, Lilly; Research grant / Funding (self): ASLAN Pharmaceuticals, AstraZeneca, Baxalta/Shire, Bayer, Bristol-Myers Squibb, Chugai Pharma, Eisai, Kowa, Kyowa Hakko Kirin, Lilly, Merck Serono, MSD, NanoCarrier, Novartis, Ono Pharmaceutical, Taiho Pharmaceutical, Takara Bio, Yakult Honsha. M. Sung: Advisory / Consultancy: Bayer; Advisory / Consultancy: Eisai; Advisory / Consultancy: Exelixis. A.D. Baron: Speaker Bureau / Expert testimony: Amgen; Speaker Bureau / Expert testimony: Bristol-Myers Squibb; Speaker Bureau / Expert testimony: Genentech/Roche; Speaker Bureau / Expert testimony: Lilly; Speaker Bureau / Expert testimony: Merck. M. Kudo: Honoraria (self), Research grant / Funding (self): AbbVie; Honoraria (self), Advisory / Consultancy: Bayer; Honoraria (self), Advisory / Consultancy, Research grant / Funding (self): Bristol-Myers Squibb; Honoraria (self): EA Pharma; Honoraria (self), Advisory / Consultancy: Eisai; Honoraria (self): Gilead Sciences; Honoraria (self): Merck Serono; Honoraria (self), Advisory / Consultancy: MSD; Honoraria (self): Novartis; Honoraria (self): Pfizer; Honoraria (self), Research grant / Funding (self): Taiho Pharmaceutical; Research grant / Funding (self): Astellas Pharma; Research grant / Funding (self): Chugai Pharma; Research grant / Funding (self): Daiichi Sankyo; Research grant / Funding (self): Otsuka. T. Okusaka: Honoraria (self): AstraZeneca, Bayer, Bristol-Myers Squibb, Celgene, Chugai Pharma, Daiichi Sankyo, EA Pharma, Eisai, Fujifilm, Lilly Japan, Nippon Chemiphar, Nobelpharma, Novartis, Ono Pharmaceutical, Pfizer, Sumitomo Dainippon, Taiho Pharmaceutical, Teijin Pharma, Yakult; Advisory / Consultancy: Daiichi Sankyo, Sumitomo Dainippon, Taiho Pharmaceutical, Zeria Pharmaceutical; research funding from AstraZeneca, Baxter, Bayer, Chugai Pharma, Dainippon Sumitomo Pharma, Eisai, Kowa, Kyowa Hakko Kirin, Lilly Japan, Merck Serono, NanoCarrier, Nippon Boeh. M. Kobayashi: Speaker Bureau / Expert testimony: Eisai Inc. H. Kumada: Honoraria (self): AbbVie; Honoraria (self): Bristol-Myers Squibb; Honoraria (self): Gilead Sciences; Honoraria (self): MSD; Honoraria (self): Sumitomo; Honoraria (self): Dainippon. S. Kaneko: Honoraria (self): EA Pharma, MSD, Aska Pharma, Astellas Pharma, AbbVie, Eisai, Eidia, Otsuka, Gilead Sciences, Sysmex Corporation, Daiichi Sankyo, Taisho Toyama, Sumitomo Dainippon, Taiho, Takeda, Chugai, Bayer, Bristol-Myers, Mylan EPD, Miyarisan, Mochida, Kowa, Mitsubis; Research grant / Funding (self): Gilead Sciences, AbbVie, Daiichi Sankyo, Astellas Pharma, Takeda, Nippon Boehringer Ingelheim, MSD, Ono Pharma, Pfizer, Shionogi, Teijin Pharma, Mitsubishi Tanabe, Zeria, Abbott Vascular Japan, Taisho Toyama, Novartis, Terumo Corporation, Taiho, Novo Nord. K. Mamontov: Honoraria (self): Bayer; Honoraria (self): Eisai; Honoraria (self): Merck; Honoraria (self): MSD; Honoraria (self): Medtronic; Honoraria (self): Roche. T. Meyer: Advisory / Consultancy: Bristol-Myers Squibb; Advisory / Consultancy: Bayer; Advisory / Consultancy: Eisai; Advisory / Consultancy: BTG; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: BeiGene; Advisory / Consultancy: Tarveda; Advisory / Consultancy: MSD. K. Mody: Full / Part-time employment: Eisai Inc. T. Kubota: Full / Part-time employment: Eisai Co., Ltd. K. Saito: Full / Part-time employment: Eisai Inc. A.B. Siegel: Full / Part-time employment: Merck. L. Dubrovsky: Full / Part-time employment: Merck. A.X. Zhu: Advisory / Consultancy: AstraZeneca; Advisory / Consultancy, Research grant / Funding (institution): Bayer; Advisory / Consultancy, Research grant / Funding (institution): Bristol-Myers Squibb; Advisory / Consultancy: Eisai; Advisory / Consultancy: Exelixis; Advisory / Consultancy, Research grant / Funding (institution): Merck; Advisory / Consultancy, Research grant / Funding (institution): Lilly; Advisory / Consultancy, Research grant / Funding (institution): Novartis; Advisory / Consultancy: Sanofi. All other authors have declared no conflicts of interest.