BeiGene Presents Clinical Data from Two Phase 2 Trials of Pamiparib at the 2021 ASCO Annual Meeting - Seite 3

• 87 patients (98.9%) experienced at least one treatment-emergent adverse event (TEAE) of any grade and 54 patients (61.4%) experienced at least one Grade ≥3 TEAE;
• 87 patients (98.9%) experienced at least one treatment-related TEAE of any grade, and 53 patients (60.2%) experienced at least one Grade ≥3 treatment-related TEAE, with the most common (≥5%) being anemia (39.8%), neutrophil count decrease (29.5%), white blood cell count decrease (21.6%), platelet count decrease (9.1%), leukopenia (5.7%), and neutropenia (5.7%);
• Serious TEAEs were reported in 19 patients (21.6%) and serious treatment-related TEAEs were reported in 15 patients (17.0%);
• Two patients experienced treatment discontinuation due to TEAEs, both considered treatment-related; and
• TEAEs leading to death occurred in one patient (1.1%) and no treatment-related TEAEs leading to death were reported.

Results from Phase 2 Trial of Pamiparib vs. Placebo in Locally Advanced or Metastatic Gastric Cancer

Poster No. 3109

PARALLEL 303 is a double-blind, randomized, multicenter Phase 2 trial (NCT03427814) comparing the safety and efficacy of pamiparib vs placebo as maintenance therapy in patients with inoperable locally advanced or metastatic gastric cancer that responded to platinum-based first-line chemotherapy. A total of 136 patients were enrolled and due to slow enrollment and a change in the standard of care for this patient population, the trial did not meet the planned target enrollment of approximately 540 patients. Patients were randomized 1:1 to receive pamiparib 60 mg orally twice daily (n = 71) or placebo (n = 65) in 28-day cycles. The primary endpoint was PFS as assessed by investigator per RECIST v1.1; secondary endpoints included time to subsequent treatment (TSST), ORR, DoR, and time to response (TTR) as assessed by investigator, OS, and safety. At the time of data analysis, OS data were immature.

“Many patients with gastric cancer become resistant to currently available therapies in later stages of disease, so continued research is crucial to find medicines that may improve outcomes and survival,” said Fortunato Ciardiello, M.D., Ph.D., Second University of Naples, Italy and a principal investigator of the trial. “Though the PARALLEL 303 study did not achieve statistical significance, these results help us advance understanding of the role that PARP inhibition has in metastatic gastric cancer and reinforces pamiparib’s safety profile and potential clinical benefit for appropriate patients.”