Hanmi reports early safety, efficacy for its bispecific cancer drug

(Hanmi Pharmaceutical)

South Korea‘s Hanmi Pharmaceutical said Tuesday that it has confirmed early signs of efficacy and safety in a global Phase 1 clinical trial of BH3120, a next-generation bispecific immuno-oncology drug.

BH3120 is an investigational cancer therapy developed using Hanmi’s proprietary bispecific antibody platform, Pentambody. The drug is designed so that a single antibody simultaneously binds to two different targets, combining the effects of targeted cancer therapy with immune activation.

Specifically, BH3120 targets PD-L1 on the surface of tumor cells and 4-1BB on immune cells, acting as a “bridge” that helps immune cells more easily recognize and destroy cancer cells. By activating immune responses only in the tumor microenvironment, the drug aims to enhance antitumor efficacy while minimizing systemic toxicity.

Hanmi said previous antibody candidates targeting 4-1BB have faced challenges related to either limited efficacy or safety concerns. In contrast, BH3120 demonstrated strong antitumor activity in multiple preclinical studies, along with a clear decoupling of immune activation between the tumor microenvironment and normal tissues — a profile the company says supports its potential as both an effective and safer immuno-oncology therapy.

A global Phase 1 trial is currently underway in South Korea and the United States involving patients with advanced or metastatic solid tumors who have failed standard treatments, including immuno-oncology therapies. The study is evaluating the safety and tolerability of BH3120 as a monotherapy as well as in combination with Keytruda.

Hanmi presented interim clinical data for BH3120 in a poster session at the ESMO Immuno-Oncology Congress 2025, held in London from Feb. 10 to 12.

According to the company, dose-escalation is progressing as planned in both the monotherapy and combination cohorts, with no dose-limiting toxicities observed to date. Early antitumor activity has also been seen in some patients who did not respond to existing standard therapies, reinforcing BH3120’s potential for patients with limited treatment options.

“This trial marks Hanmi’s first global clinical development project using our proprietary bispecific antibody platform, Pentambody, at a time when bispecific immuno-oncology therapies are gaining global attention,” said Dr. Noh Young-su, head of Hanmi’s clinical research and development team. “We will continue working to overcome the limitations of existing treatments and advance a next-generation immunotherapy that delivers both enhanced efficacy and a strong safety profile.”

Shares of Hanmi Semiconductor finished at 177,800 won, up 2.66 percent from the previous session. DYP ended at 4,670 won.