131MO - Tislelizumab (TIS) plus chemotherapy (Chemo) vs placebo (PBO) plus chemo as first-line (1L) treatment of advanced gastric or gastroesophageal junction adenocarcinoma (GC/GEJC): Patient reported outcomes (PRO) in the Asian subgroup of the RATIONALE-305 study

Background

RATIONALE-305 (NCT03777657) demonstrated statistically significant and clinically meaningful improvements in overall survival (OS) with TIS + chemo versus PBO + chemo and better PROs as 1L treatment in patients (pts) with advanced GC/GEJC. Post-hoc analysis examined PROs endpoints in the Asian subgroup of RATIONALE-305.

Methods

Adults with previously untreated, unresectable, or metastatic GC/GEJC were randomized (1:1) to TIS 200 mg or PBO intravenously once every 3 weeks plus investigator-choice of chemo. PROs were a secondary endpoint and were measured using the EORTC QLQ-C30 and the QLQ-STO22. A mixed model for repeated measures using PRO endpoints at Cycles 4 and 6 was performed. Time to deterioration was also examined.

Results

Asian pts in RATIONALE-305 receiving TIS + chemo (n=376) had improved outcomes versus PBO + chemo (n=372), as indicated by differences in least-squares (LS) mean change from baseline to Cycle 6 for QLQ-C30 Global Health Status (GHS)/Quality of Life (QoL) (2.76 [95% CI: 0.24 to 5.28]), physical functioning (fx) (2.10 [-0.07 to 4.27]), fatigue (-2.39 [-5.37 to 0.58]), and the STO22 index score (-1.56 [-3.26 to 0.14]), as well as maintaining upper gastrointestinal (GI) symptoms (-1.59 [-3.57 to 0.39)] and pain (-1.94 [-4.38 to 0.50]). Pts receiving TIS + chemo also had a lower risk for deterioration of physical fx (HR: 0.75 [95% CI: 0.57 to 0.98]), STO22 index score (0.65 [0.43 to 0.98]), and upper GI symptoms (0.72 [0.53 to 0.97]).

Conclusions

Asian pts in RATIONALE-305 treated with TIS + chemo had better PRO outcomes versus pts treated with PBO + chemo. These results corroborating the PRO findings in the intention-to-treat population, along with prolonging of OS, support the benefit of TIS + chemo as a potential 1L treatment option for GC/GEJC Table: 131MO

Summary LS mean (95% CI) of PROs in the Asian subgroup

Clinical trial identification

NCT03777657.

Editorial acknowledgement

Editorial support, under the direction of the authors, was provided by Envision Pharma Inc.

Legal entity responsible for the study

BeiGene, Ltd.

Funding

BeiGene, Ltd.

Disclosure

K. Kato: Financial Interests, Personal, Invited Speaker: Ono Pharmaceutical, Bristol Myers Squibb, Merck and Co; Financial Interests, Personal, Advisory Board: Ono Pharmaceutical, Bristol Myers Squibb, Merck and Co, Bayer, AstraZeneca, Beigene, Taiho, Merck BioPharma, Daiichi Sankyo; Financial Interests, Institutional, Coordinating PI: Ono Pharmaceuticals, Merck & Co; Financial Interests, Institutional, Local PI: Bayer, AstraZeneca, Beigene, Taiho, Oncolys Biopharma, Merck Biopharma. R. Xu: Financial Interests, Personal, Invited Speaker: BMS, MSD, Hutchison Pharm; Financial Interests, Personal, Advisory Board: Henrui, Beigene, Astalas, Merck, Junshi, Innovent, Keymed Biosience. D. Oh: Financial Interests, Personal, Advisory Board: AstraZeneca, Novartis, Genentech/Roche, Merck Serono , Bayer, Taiho, ASLAN, Halozyme, Zymeworks, BMS/Celgene, BeiGene, Basilea, Turning Point, Yuhan, Arcus Biosciences, IQVIA, MSD, LG Chem, Astellas, AbbVie, J-Pharma, Mirati Therapeutics, Eutilex, Moderna, Idience, Alligator Bioscience AB; Financial Interests, Institutional, Research Grant: AstraZeneca, Novartis, Array, Eli Lilly, Servier, BeiGene, MSD, Handok. K. Lee: Financial Interests, Personal, Advisory Board: AbbVie, Astellas, BMS (Korea), Daiichi Sankyo (Korea), Merck Sharp & Dohme (Korea), Metafines; Financial Interests, Personal, Invited Speaker: Bayer (Korea), Merck KCaA (Korea); Financial Interests, Institutional, Local PI, For conducting clinical trials: ALX Oncology, Amgen, Arcus Biosciences, Astellas Pharma, AstraZeneca, BeiGene, Bolt therapeutics, Daiichi Sankyo, Elevar, Erasca, Inc, Exelixis, Genome & Company, GSK, IgM Biosciences, InventisBio, Jazz Pharmaceuticals, Leap therapeutics, Macrogenics, MedPacto, Medicenna, Merck KGaA, Merck Sharp & Dohme, Metafines, Ono Pharmaceutical, Panolos Bioscience, Pfizer, Seagen, TRIO Oncology, Taiho Pharmaceutical, Trishula therapeutics, Wellmarker Bio, Y-BIOLOGICS; Non-Financial Interests, Personal, Leadership Role, SMC chair of ASPEN-06 study: ALX Oncology. H. Hirano: Financial Interests, Personal, Invited Speaker: Taiho Pharmaceutical, Ono Pharmaceutical, Teijin Phama, Novartis, Bristol Myers Squibb; Financial Interests, Institutional, Research Grant: Chugai Pharmaceutical, Daiichi Sankyo, Taiho Pharmaceutical, Ono Pharmaceutical, Janssen Pharmaceutical, Merck Biopharma, Bristol Myers Squibb, Pfizer, Eisai, Amgen, Astellas, Seagen, MSD, Incyte, BeiGene, Novartis, ALX Oncology, PPD, Nippon Boehringer Ingelheim. H. Xu, T. Sheng, G. Barnes: Financial Interests, Institutional, Full or part-time Employment: BeiGene (Beijing) Co., Ltd; Financial Interests, Personal, Stocks/Shares: BeiGene (Beijing) Co., Ltd. All other authors have declared no conflicts of interest.