• HD-B001A in combination with paclitaxel demonstrated a 37.5% overall response rate (ORR) in 24 patients with BTC treated in the second- and third- line settings; at least one response was observed in each of the four anatomical subtypes of BTC
• Median progression free survival (PFS) was 9.4 months and median overall survival (OS) was 12.5 months  
• Handok is partnering with Compass Therapeutics for a global Phase 2/3 study which is based in the data of phase 2 study in Korea

Handok (CEOs Young-Jin Kim & Jin-Ki Baek) announced that the Phase 2 Data of HD-B001A (CTX-009 and ABL001) in patients with advanced biliary tract cancer (BTC) is presented in a poster session at the 2023 American Society of Clinical Oncology Gastrointestinal Cancers (ASCO GI) Symposium taking place in San Francisco, CA on January 20, 2023 (local time).

HD-B001A is a next-generation anticancer drug under development using bispecific antibody platform technology. Handok has a license agreement with ABL Bio and has rights in Korea. Since 2021, the company has been leading Phase 2 of HD-B001A in advanced BTC patients in Korea. Based on the Phase 2 Data in Korea, it is moving towards a global Phase 2/3 study and has also partnered with Compass Therapeutics to conduct a Phase 2/3 clinical study.

The Phase 2 study was conducted at four leading medical centers in Korea to evaluate the efficacy and safety of HD-B001A in combination with paclitaxel in patients with unresectable, advanced, metastatic, or recurrent BTC who have previously received first-line or second-line systemic chemotherapy.   

In the primary analysis of all 24 patients participating in the study, HD-B001A in combination with paclitaxel demonstrated a 37.5% Overall Response Rate (ORR) based on 9 patients with Partial Responses (PRs). Of the 11 patients who had received the combination therapy in the second-line setting, 7 patients achieved a PR, leading to an ORR of 63.6% in this sub-group.

After a median follow-up of approximately 12 months, the median Progression Free Survival (PFS) was 9.4 months, and the median Overall Survival (OS) was 12.5 months. For reference, one regimen that has been studied in patients with advanced BTC is FOLFOX, the regimen recommended in the guidelines of the National Comprehensive Cancer Network (NCCN) for patients with BTC treated in the second-line setting. FOLFOX demonstrated a median PFS of 4.0 months and a median OS of 6.2 months in a randomized study. In addition, treatment-emergent adverse events (TEAEs) of Grade 3 or above were reported in 95.8% of patients regardless of the use of HD-B001A or paclitaxel, including decreased neutrophil count, hypertension, anemia and decreased platelet count.

“It is encouraging to see HD-B001A attract much interest in oncologists and patients as a potential treatment option for patients with advanced BTC who have a poor prognosis and have been pre-treated with poor treatment options and with such significant unmet needs,” said Young-Jin Kim, Chairman of Handok. “With the positive results of the Phase 2 study in Korea, Handok and Compass Therapeutics are collaborating to obtain additional efficacy and safety data in a global Phase 2/3 study.”  

Handok has partnered with U.S.-based bio venture firm Compass Therapeutics to conduct a global Phase 2/3 study in patients with BTC. Based on the results of the global Phase 2/3 study, the company is seeking to file a biologics license application (BLA) submission in 2024. HD-B001A is also being developed for the treatment of colorectal cancer, and a Phase 2 trial is currently underway. 

According to the statistics released by the National Cancer Registry in 2020, the five-year survival of BTC is 28%, which is the second lowest among common types of cancer following pancreatic cancer (13.9%). Only 10% of patients with BTC are diagnosed in an early stage when they would be candidates for surgical resection. The vast majority are detected with locally advanced or metastatic BTC, for which there are very few therapeutic options.