お知らせ • Jun 02
BeOne Medicines Ltd. Presents New Data from Solid Tumor Pipeline At ASCO 2026
BeOne Medicines Ltd. announced new data from its solid tumor pipeline being presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting (May 29–June 2, Chicago). Data from three differentiated BeOne pipeline assets will be presented, including: CDK4 inhibitor (BGB-43395) (poster presentation): First disclosure of anti-tumor activity in first-line (1L) HR+/HER2- metastatic breast cancer. B7-H4 ADC (BG-C9074) (rapid oral presentation): Phase 1 dose-escalation and safety expansion data in advanced solid tumors. GPC3x4-1BB (BGB-B2033) bispecific antibody (rapid oral presentation): First clinical data in advanced solid tumors, including hepatocellular carcinoma (HCC), the most common type of liver cancer. BeOne will present data about its highly selective CDK4 inhibitor, BGB-43395, in 1L HR+/HER2- metastatic breast cancer, in combination with letrozole, showing promising anti-tumor activity and a favorable safety profile, characterized by infrequent low-grade hematologic toxicities and manageable GI events, which were further mitigated when administered with food. The 240 mg dose of BGB-43395 plus letrozole resulted in a confirmed overall response rate (ORR) of 68.4% (95% CI: 43.4–87.4) and unconfirmed ORR of 73.7% (95% CI: 48.8-90.9). The 400 mg dose plus letrozole resulted in a confirmed ORR of 63.2% (95% CI: 38.4–83.7) and unconfirmed ORR of 73.7% (95% CI: 48.8-90.9). Low levels of hematologic treatment-related adverse events (TRAEs) with Grade =3 neutropenia reported in 5.3% of patients at the 240 mg dose level and 0% at 400 mg, as well as low frequency of fatigue and asthenia; supports profile and validates the molecule’s high selectivity for CDK4. GI TRAEs were mitigated when administered with food, all of which were Grade 1. Median study follow-up was 12.5 (range, 3.1-15.2) months, 12.4 (range, 8.0-15.0) months, and 10.8 (range, 3.2-12.9) months for the 240 mg, 400 mg, and 600 mg dose groups, respectively. These compelling safety and efficacy findings support the rationale to initiate a global, randomized Phase 3 clinical trial with BGB-43395 in combination with letrozole in 1L HR+/HER2- metastatic breast cancer. The trial, KANDELA-302 (NCT07492641), will begin enrolling patients this month. Data at ASCO from BeOne’s B7-H4-targeting antibody-drug conjugate (ADC), BG-C9074, include results from Phase 1 dose-escalation and safety-expansion cohorts, demonstrating a combination of early efficacy signals and a favorable tolerability profile. At doses under consideration for future development, confirmed ORR of 45.5% and unconfirmed ORR of 54.5% in ovarian cancer (OC), and 40.0% in triple-negative breast cancer, with median study follow-up of 6.6 (range, 0.3-20.8) months. Anti-tumor activity demonstrated in OC regardless of B7-H4 expression level. Treatment was generally well tolerated with low rates of discontinuation at 1 with five-year survival rates of only approximately 20%. At doses =300 mg, confirmed ORR was 28.9% and unconfirmed ORR was 31.6%, with median study follow-up of 4.8 (range, 0.3-15.5) months. Treatment was generally well tolerated across all dose levels (1-1000 mg every three weeks [Q3W], N = 61) with no significant dose-dependent increase in rates of treatment-emergent adverse events (TEAEs): 68.9% (42) of patients experienced TEAEs; of these: 47.5% (29) were treatment related, 8.2% (5) of patients experienced Grade =3 TRAEs, 4.9% (3) were treatment-related serious adverse events. TEAE leading to treatment discontinuation occurred in 3.3% (2) of patients. Dose limiting toxicity occurred in 1.6% (1) of patients. TRAEs that occurred in >5% of patients were limited to increases in alanine aminotransferase (ALT) and aspartate aminotransferase (AST), both occurring at Grade =3 in only 1.6% of patients. BGB-B2033 300 mg Q3W 600 mg Q3W 1000 mg Q3W (N=14) (N=14) (N=10) Confirmed ORR (complete response + partial response), n (%) 4 (28.6) 5 (35.7) 2 (20.0) Unconfirmed ORR (complete response + partial response), n (%) 4 (28.6) 5 (35.7) 3 (30.0) An additional PR (week 36) was reported at 1000 mg, with patient still on treatment, pending confirmation in the next tumor assessment. With ORR levels in heavily pretreated patients on par with the current first-line immunotherapy combination standard of care and a differentiated safety profile, BeOne is moving rapidly to advance clinical development of BGB-B2033. The Company has already announced the initiation of a potentially registration-enabling pivotal study in late-line HCC and planned expansion into earlier lines of therapy and additional tumor types, with the ambition to establish a new standard of care in this difficult-to-treat cancer. BGB-43395 is an investigational cyclin-dependent kinase (CDK) 4 inhibitor being studied in a global clinical development program in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer. The program includes KANDELA-302 (NCT07492641), a randomized Phase 3 clinical trial, initiated in Second Quarter 2026 in first-line metastatic HR+/HER2- breast cancer. BGB-43395 is highly potent and selective CDK4 inhibitor and has the potential to reduce the dose-limiting hematologic toxicities that exist with the current CDK4/6 standard of care and may improve tolerability and enable deeper CDK4 inhibition. BG-C9074, an investigational topoisomerase I inhibitor ADC that targets the B7-H4 protein, which is broadly expressed in breast and gynecologic cancers, is designed with an innovative drug linker to deliver a potent cancer-killing drug directly to the cancer cells. In a Phase 1 study of BG-C9074 (NCT06233942), patients with advanced solid tumors, irrespective of B7-H4 expression, received BG-C9074 every 3 weeks in escalating doses from 1 to 9 mg/kg. A subsequent safety expansion cohort received BG-C9074 in doses ranging from 4 to 8 mg/kg. Endpoints included safety, recommended dose for expansion, preliminary antitumor activity and pharmacokinetic measures. BGB-B2033 is a bispecific antibody targeting GPC3 (glypican 3), a tumor-specific antigen highly expressed in hepatocellular carcinoma (HCC), and 4-1BB, a co-stimulatory receptor associated with T-cell activation and tumor reactivity in HCC. The molecule has been designed with reduced antibody-dependent cellular cytotoxicity (ADCC) to prevent systemic toxicity. BGB-B2033 is being investigated in a Phase 1 study (NCT06427941) in patients with GPC3-expressing advanced solid tumors with at least one prior line of therapy. Patients received BGB-B2033 every 3 weeks in eight escalating dose levels from 1 to 1000 mg, with various safety and anti-tumor activity endpoints. In December 2025, the FDA granted Fast Track Designation to BGB-B2033 for the treatment of HCC, followed by Orphan Drug Designation in March 2026.
