BeiGene Presents Clinical Data from Two Phase 2 Trials of Pamiparib at the 2021 ASCO Annual Meeting

BeiGene, Ltd. (NASDAQ: BGNE; HKEX: 06160), a global biotechnology company focused on developing and commercializing innovative medicines worldwide, today announced that its PARP inhibitor pamiparib showed efficacy in patients with HER2-negative breast cancer and demonstrated numerically higher but not statistically significant progression-free survival in gastric cancer. The results in gastric cancer may have been influenced by the fact that the study did not meet the planned enrollment target. These data were presented in poster sessions at the 2021 American Society of Clinical Oncology Annual Meeting (ASCO 2021) taking place virtually on June 4-8, 2021, and included initial reporting from a Phase 2 trial evaluating pamiparib in locally advanced or metastatic HER2-negative (HER2[-]) breast cancer with germline BRCA1/2 mutation (gBRCA1/2m) and initial reporting of a randomized Phase 2 trial of pamiparib as maintenance therapy in patients with inoperable locally advanced or metastatic gastric cancer who responded to platinum-based first-line chemotherapy.

“We are pleased to share results from our pamiparib clinical development program, focused on diseases with high prevalence, as we work towards our mission of improving outcomes for patients in need,” commented Yong (Ben) Ben, M.D., Chief Medical Officer, Immuno-Oncology at BeiGene. “We are encouraged by the positive results for pamiparib in HER2-negative breast cancer, a devastating disease and leading cause of cancer death among women, and while it did not achieve statistical significance in gastric cancer, we hope these findings can improve understanding among the scientific community and reinforce the tolerability of pamiparib as we advance its global development.”

Results from Phase 2 Trial of Pamiparib in Locally Advanced or Metastatic HER2-Negative Breast Cancer with gBRCAm

Poster No. 1087

This single-arm, open label, multi-center Phase 2 trial (NCT03575065) was designed to evaluate the safety and efficacy of pamiparib in patients with locally advanced or metastatic HER2-negative breast cancer, with deleterious or suspected deleterious gBRCA1/2m, who received no more than two prior lines of chemotherapy. A total of 88 patients were enrolled, including 62 patients with triple-negative breast cancer (TNBC cohort) and 26 patients with hormone receptor-positive (HR[+]) and HER2(-) breast cancer (HR[+] cohort). Fifty-five patients in the TNBC cohort and 21 patients in the HR(+) cohort had measurable disease at baseline per independent review committee (IRC). The primary endpoint of the trial was objective response rate (ORR) as assessed by IRC per RECIST v1.1; secondary endpoints included investigator-assessed ORR, duration of response (DoR), best overall response (BOR), progression-free survival (PFS), clinical benefit rate (CBR), and disease control rate (DCR) as assessed by IRC and investigator, and overall survival (OS), as well as safety and tolerability.