1584P - Conversion effect of PD-1 antibody camrelizumab (Cam) combined with modified FLOT (mFLOT) regimen in patients(pts) with initially unresectable locally advanced or limited metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma

Background

The AIO-FLOT3 Trial suggested that conversion therapy might improve outcome in pts with metastatic gastric cancer (GC). We conducted this prospective, single-arm, phase II trial to improve conversion efficacy of ICIs combined with mFLOT regimen (fluorouracil, oxaliplatin, and nab-PTX) in pts with initially unresectable locally advanced or limited metastatic GC or GEJ adenocarcinoma.

Methods

Eligible pts received Cam 200mg, oxaliplatin 85 mg/m², nab-PTX 125 mg/m² or with trastuzumab if Her2 positive, each was an IV followed by fluorouracil 2400 mg/m² as a 48-h continuous iv on day 1, every 2 weeks. Pts were assessed for tumor response and surgical feasibility every 3 cycles. The primary endpoint was R0 conversion rate.

Results

35 pts were enrolled up to 04/2023. 30 pts were evaluable. The median age was 50y. Male was 76.7%. The metastatic sites included liver 50.0% (15), retroperitoneal lymph nodes (LNs) 33.0% (10), axillary and supraclavicular LNs 6.7% (2), Krukenberg 3.3% (1), adrenal gland 3.3% (1), and locally advanced unresectable 10% (3). 7(23.3%) pts had two or more unresectable lesions. 4 pts were dMMR/MSI-H and 4 were Her2 positive. ORR was 86.7% and DCR was 96.7%. 25(83.3%) pts were assessed as resectable after conversion therapy. One pt refused surgery and 2 were cCR under observation. 22 pts (73.3%) received operation with R0 resection and no perioperative mortality. With 2 cCR included, R0 conversion rate was 80.0% (24/30). 5 pts (22.7%) achieved pCR and 12(54.5%) achieved MPR. Grade 3 AEs included 2 cases of rash, 1 case of adrenal insufficiency, 1 case each of ALT, AST elevation and febrile neutropenia. 1 pt was Grade 4 Neutrophil count decreased. (Table)

Table: 1584P

Conclusions

Cam combined with mFLOT regimen safely induced a high conversion rate, with very high R0 resection, pCR and MPR. The findings warrant further prospective investigations.

Clinical trial identification

NCT04510064.

Editorial acknowledgement

Legal entity responsible for the study

Fudan University Shanghai Cancer Center.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.