Abstract 149P
Background
Surufatinib (S, a small-molecule inhibitor of VEGFR1-3, FGFR1 and CSF-1R) plus toripalimab (T, an anti-PD-1 antibody) has exhibited encouraging efficacy in an SCLC cohort in a trial evaluating S + T in pts with selected solid tumors. This study is assessing the safety, tolerability, and preliminary efficacy of S+ T+ chemotherapy (EP) as first-line regimen for SCLC pts. Here, we report the preliminary efficacy results.
Methods
This study is a phase Ⅰb/Ⅱ, single-arm study(NCT04996771). Eligible pts were≥18 years old with histologically confirmed SCLC, ECOG PS 0-1, with at least one measurable lesion. Pts with treated, stable, and asymptomatic brain metastases(BMs) are allowed. A 3+3 dose-escalation was done to determine the recommended RP2D of S+T+EP. S was dosed at 150mg, 200mg, and 250mg qd, po, Q3W in the dose level(DL)1, 2, and 3, respectively, in combination with a fixed dose of T(200mg, iv, d1, Q3W) and EP(Q3W). After 4 cycles followed by maintenance therapy with S plus T every 3 weeks. This study started escalation in the DL2. DLT was observed for 1 cycle. The primary objective of phase Ⅰb is to assess the safety and confirm the RP2D of S. The primary objective of phase Ⅱ is to estimate the PFS and the secondary endpoints including ORR, DCR, OS, and safety.
Results
At cutoff date (Sep 20, 2022), 24 pts (phase Ⅰb DL2, n=6; phase Ⅱ, n=18) were enrolled and received treatment(median age 59 years, male 70.8% , ECOG PS 1 62.5%, BMs 8.3%). Two DLTs occurred in the DL2, The RP2D was identified as S(200mg, po, qd, Q3W). Among pts with at least one post-baseline tumor assessment (evaluable pts, n=17), the confirmed ORR was 88.2%, and DCR(15 PRs, 2 SDs) was 100%. Median PFS was not reached yet. The most common treatment-emergent adverse events (TEAEs) (Total; Grade ≥3) were alopecia(66.7%; 0), white blood cell count decreased (57.1%; 28.6%), anemia(57.1%; 0), decreased appetite(52.4%; 0) and constipation(47.6%; 0).
Conclusions
Surufatinib plus toripalimab and etoposide combined with cisplatin showed promising anti-tumor activity and acceptable toxicity for the 1L treatment of SCLC. The combination of the 4 agents might be a novel 1L therapeutic option for SCLC.
Clinical trial identification
NCT04996771 Release date: November 9, 2021.
Legal entity responsible for the study
Sun Yat-sen University Cancer Center.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.