1669OIMMUNOSARC: A collaborative Spanish (GEIS) and Italian (ISG) sarcoma groups phase I/II trial of sunitinib plus nivolumab in advanced soft tissue and bone sarcomas: Results of the phase II- soft-tissue sarcoma cohort

Abstract Background The combination of sunitinib (SU) and nivolumab (NI) showed to be safe in the previous phase I of IMMUNOSARC study. We present the results of the phase II of the combination of SU-NI in the advanced STS (pts) cohort. Methods Pretreated progressing pts, ECOG 0-1, with UPS, synovial (SS), clear cell (CCS), angio(AS)/epithelioid hemangioendothelioma (EH), solitary fibrous tumor (SFT), epithelioid sarcoma (ES), extraskeletal myxoid chondrosarcoma (ECM) or alveolar soft part sarcoma (ASPS) were eligible. SU 37.5 mg/d as induction was given days 1-14 and then reduced to 25mg/d continuously. NI was administered at 3 mg/Kg every 2 weeks from week 3. SU-NI was maintained up to progression or intolerance. Primary end-point was progression-free survival rate (PFSR) at 6 months (m) by RECIST. Secondary end-points: overall survival (OS), objective response rate (ORR) by RECIST and CHOI and toxicity. Results From Nov 2017 to Dec 2018, 50 eligible pts were included in 8 centres: (M/F 30/20), median age 45y (19-77). Diagnosis was: SS in 9 (18%), CCS in 7 (14%), SFT in 7 (14%), UPS in 6 (12%), ES in 6 (12%), AS in 5 (10%), ECM in 4 (8%), ASPS in 3 (6%) and other in 3 (6%). With a median FU of 6.1 m (0-13), 23 pts (46%) progressed based on RECIST with a median PFS of 5.9 m (95% IC 2.7-9.1) and 9 pts (18%) died, with median OS not reached yet. PFSR at 3 and 6 m based on local evaluation were 69% and 50% respectively and OS at 3 and 6 m were 86% and 77%. Based on central radiological review (RECIST, 43 evaluable pts), there were 1 CR (2.3%), 3 PR (7%), 26 SD (60%, 12 pts showing shrinkage) and 13 PD (30%). By CHOI (31 evaluable), there were 19 PR (61.3%), 8 SD (25.8%) and 4 PD (13%). Most relevant G3/4 toxicities were: AST increase 6 (11.8%), ALT increase 5 (9.8%), neutropenia 5 (9.8%), fatigue 3 (5,9%), thrombocytopenia 2 (3.9%), diarrhea 2 (3.9%), renal function impairment 2 (3.9%), without toxic deaths. Conclusions The trial met its primary endpoint. SU-NI is an active combination for the treatment of advanced selected STS patients, with 50% of patients free of progression at 6m. Further exploration of immunomodulatory strategies is warranted in selected sarcoma subtypes. Clinical trial identification NCT03277924. Legal entity responsible for the study Grupo Espanol de Investigacion en Sarcomas (GEIS). Funding Pfizer and BMS. Disclosure J. Martin Broto: Honoraria (self), Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: PharmaMar; Honoraria (self), Speaker Bureau / Expert testimony, Research grant / Funding (institution): Novartis; Honoraria (self): Bayer; Honoraria (self): Amgen; Travel / Accommodation / Expenses: Pfizer; Honoraria (self), Research grant / Funding (institution): Lilly; Research grant / Funding (institution): Eisai; Research grant / Funding (self): GlaxoSmithKline . N. Hindi: Honoraria (self), Research grant / Funding (institution), Travel / Accommodation / Expenses: PharmaMar; Research grant / Funding (institution): Eisai; Research grant / Funding (institution): Novartis. G.E. Grignani: Travel / Accommodation / Expenses: PharmaMar; Travel / Accommodation / Expenses: Lilly; Travel / Accommodation / Expenses: Novartis. A. Redondo: Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Advisory / Consultancy, Travel / Accommodation / Expenses: AstraZeneca; Advisory / Consultancy: Tesaro; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: PharmaMar; Advisory / Consultancy: Clovis; Research grant / Funding (institution): Eisai. C. Valverde: Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: PharmaMar; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Lilly; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Novartis; Advisory / Consultancy, Travel / Accommodation / Expenses: Bayer; Advisory / Consultancy, Research grant / Funding (institution): Bluprint; Travel / Accommodation / Expenses: Pfizer; Research grant / Funding (institution): Karyopharm; Research grant / Funding (institution): Decyphera; Research grant / Funding (institution): Incyte. A. Lopez Pousa: Travel / Accommodation / Expenses: PharmaMar. S. Stacchiotti: Research grant / Funding (institution): Pfizer . E. Palmerini: Advisory / Consultancy, Research grant / Funding (institution): Daiichi Sankyo; Advisory / Consultancy: Amgen; Advisory / Consultancy, Travel / Accommodation / Expenses: Lilly; Research grant / Funding (institution): Bristol-Myers Squibb (BMS); Research grant / Funding (institution): Pfizer; Research grant / Funding (institution), Travel / Accommodation / Expenses: PharmaMar; Travel / Accommodation / Expenses: Takeda. D.S. Moura: Research grant / Funding (institution), Travel / Accommodation / Expenses: PharmaMar; Research grant / Funding (institution), Travel / Accommodation / Expenses: Eisai; Research grant / Funding (institution): Novartis. L. D’Ambrosio: Travel / Accommodation / Expenses: PharmaMar; Travel / Accommodation / Expenses: Lilly; Advisory / Consultancy: PSI. J.A. Lopez Martin: Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: MSD; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Advisory / Consultancy: Pierre Fabre; Advisory / Consultancy: Celgene; Advisory / Consultancy: Novartis; Advisory / Consultancy: Amgen; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Lilly; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses, Shareholder / Stockholder / Stock options, Licensing / Royalties: PharmaMar; Advisory / Consultancy: Chobani; Advisory / Consultancy: Pfizer. All other authors have declared no conflicts of interest.