For patients with advanced squamous cell esophageal carcinoma (ESCC) who have exhausted standard treatment options, a new investigational therapy is showing early promise. Results from a Phase I study suggest BL-B01D1,a first-in-class antibody-drug conjugate developed by Bio-Therapeutic Corporation,may offer a potential benefit for this difficult-to-treat population. The research, conducted by scientists at Peking University Cancer Hospital and Institute, examined the drug’s safety and efficacy in patients whose cancer had progressed despite prior immunotherapy.
For patients with advanced squamous cell esophageal carcinoma (ESCC) whose cancer has progressed despite immunotherapy, treatment options are limited.
New data suggest a first-in-class antibody-drug conjugate, BL-B01D1, shows promise in this challenging patient population. The investigational therapy combines a bispecific antibody targeting EGFR and HER3 with a topoisomerase-I inhibitor, delivered via a cleavable linker. Squamous cell esophageal cancer is a particularly aggressive form of esophageal cancer, and finding effective treatments after initial therapies fail is a critical need.
Researchers at Peking University Cancer Hospital and Institute analyzed Phase I study data from 82 patients with previously treated ESCC to assess the safety and efficacy of BL-B01D1. The primary goal of the study was to determine the recommended dose for Phase II trials.
Patients received either 2.0 mg/kg (n=22) or 2.5 mg/kg (n=60) of BL-B01D1 via infusion every three weeks. The confirmed objective response rate (cORR) – the percentage of patients whose tumors shrank or disappeared – was 29.3% (24 of 82) overall and 32.9% (24 of 73) in patients who were evaluable.
In the 2.5 mg/kg group, the cORR reached 39.6% (21 of 53), with a disease control rate – which includes patients with complete or partial responses, as well as stable disease – of 79.2% (42 of 53). The cORR in the 2.0 mg/kg group was 15.0% (3 of 20), with a disease control rate of 50.0% (10 of 20). Based on these findings, the researchers established a Phase II dose of 2.5 mg/kg administered every three weeks.
Treatment-related adverse events of Grade 3 or higher occurred in 63.3% of patients in the 2.5 mg/kg group. The most common side effects included anemia (28.3%), leukopenia and thrombocytopenia (both 18.3%), and neutropenia (16.7%). Two patients experienced interstitial lung disease, a serious lung condition, of Grade 3 or higher severity. These findings highlight the need for careful monitoring of patients receiving BL-B01D1 to manage potential side effects.
