On January 20, 2023 (local time), Handok will deliver a poster presentation on major results of its Phase 2 clinical trial of HD-B001A (CTX-009, ABL001) in patients with biliary tract cancer at the 2023 American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO GI 2023) being held in San Francisco, United States.

HD-B001A is an advanced anti-cancer drug being developed and utilizing a dual-antibody platform technology. Handok has entered into a license agreement with ABL Bio for rights in Korea and has been conducting a Phase 2 clinical trial of HD-B001A domestically since 2021, focusing on biliary tract cancer. In addition, based on the clinical trials in Korea, it is laying the groundwork for a global expansion of the clinical trials for HD-B001A, and collaborating with Compass Therapeutics on a clinical trial in the United States.

The Phase 2 study is administering HD-B001A in combination with paclitaxel to unresectable advanced, metastatic or recurrent biliary tract cancer patients who have received prior first or second-line systemic chemotherapy. The study was conducted at four Korean institutions, including Seoul National University Hospital.

In the first efficacy evaluation of 24 patients in the Phase 2 study, the overall response rate (ORR) of HD-B001A in combination with paclitaxel was 37.5%, with nine partial responses (PRs). Seven of eleven patients administered HD-B001A as a second-line treatment showed a partial response, resulting in an objective response rate of 63.6% in second-line treatment.

Results of a 12-month serial assessment showed the median Progression Free Survival (PFS) was 9.4 months, and the median Overall Survival (OS) rate was 12.5 months. Results of a treatment based on FOLFOX, a regimen currently recommended by the National Comprehensive Cancer Network (NCCN) guidelines for patients with advanced biliary tract cancer, showed a median PFS of 4 months and a median OS of 6.2 months. In addition, the overall treatment-emergent adverse event (TEAE) rate of grade three or higher in the Phase 2 study was 95.8%, regardless of causality to HD-B001A or paclitaxel, and included neutropenia, hypertension, anemia, and thrombocytopenia.
Handok is collaborating with Compass Therapeutics on a global Phase 2/3 clinical trial in biliary tract cancer patients. Based on the Phase 2/3 results, HD-B001A is expected to be submitted for a biologics license in 2024. In addition to biliary tract cancer, HD-B001A is also being developed as a treatment for colorectal cancer, for which a Phase 2 clinical trial is underway.