Hanmi Pharmaceutical Seeks New Frontiers in Cancer Immunotherapy with mRNA Platform

Hanmi presents 11 research abstracts, the most among Korean firms, at the world’s largest cancer research conference, AACR 2025 

Spotlight on Emerging Immunotherapies: from STING mRNA to Bispecific Antibody BH3120

Researchers from Hanmi R&D Center explained their innovative anticancer drug research to attendees using posters displayed at the American Association for Cancer Research (AACR 2025), held in Chicago from April 25 to 30 (local time).

(May 13, 2025) Hanmi Pharmaceutical, renowned for “boldly taking the road less traveled,” captured global attention at AACR 2025 with its bold and original approach to immuno-oncology, centered on the next-generation “mRNA platform.”

At this year’s AACR, held in Chicago from April 25 to 30, Hanmi unveiled results from 11 research abstracts across seven investigational drug candidates. It marked the third consecutive year the company led all Korean pharmaceutical and biotech firms in the number of presentations, reaffirming its R&D leadership and commitment to advancing new modalities that could reshape cancer treatment.

The highlight of Hanmi’s presentations was its novel STING mRNA cancer immunotherapy, designed to express the STING (Stimulator of IFN Genes) protein directly and trigger a potent immune response. This groundbreaking strategy effectively “reboots” the immune system’s ability to combat tumors by reconstructing the foundation of immune activation.

Conventional immunotherapies have primarily focused on restoring T cell function through checkpoint inhibitors. Traditional STING agonists, however, have faced limitations due to metabolic instability, inefficient intracellular delivery, and reduced STING expression in tumors, resulting in limited clinical efficacy.

Hanmi’s STING mRNA candidate overcame these challenges in preclinical studies, significantly enhancing the secretion of antitumor cytokines in both cancer and immune cells. In a colorectal cancer animal model, the therapy showed meaningful tumor-suppressing effects even as a monotherapy. Its strong potential for combination therapy further suggests it could pave the way for a new generation of immunotherapies.

Hanmi also presented two studies on a separate p53 mRNA candidate, which induces apoptosis in cancer cells by restoring intracellular expression of the tumor suppressor protein p53. In orthotopic animal models of lung and ovarian cancer, the therapy effectively inhibited tumor growth. It also demonstrated excellent synergy with taxane-based chemotherapies, showing enhanced antitumor activity when combined with Abraxane in the same preclinical models.

Meanwhile, Hanmi presented two preclinical studies on BH3120, a next-generation immunotherapy being led by Beijing Hanmi’s R&D Center and developed using its proprietary bispecific antibody platform, Pentambody. BH3120 is currently undergoing global Phase 1 trials in Korea and the U.S., both as a monotherapy and in combination with KEYTRUDA® (pembrolizumab) to evaluate its safety and tolerability. In parallel, Beijing Hanmi is conducting a wide range of nonclinical studies to deepen the understanding of the drug’s mechanism of action.

At AACR, Hanmi presented data from a study evaluating the liver toxicity risk of BH3120 using a newly developed high-sensitivity assessment model, along with gene-level analyses examining the compound’s impact on the immune environment within simulated tumor tissues. These insights are expected to play a key role in interpreting clinical outcomes and shaping future development strategies.

Hanmi also introduced a lineup of targeted therapies: ▲ Two studies on the EZH1/2 dual inhibitor (HM97662) ▲ Two studies on the selective HER2 inhibitor (HM100714) ▲ One study on the MAT2A inhibitor (HM100760) ▲ One study on the SOS1 inhibitor (HM101207)

HM97662, the EZH1/2 dual inhibitor, significantly outperformed existing treatments in solid tumor animal models, including small-cell lung cancer, when combined with standard chemotherapies. Leveraging this approach, the company identified a novel biomarker indicative of enhanced chemosensitivity in small-cell lung cancer (SCLC) and presented the findings. Hanmi Pharmaceutical's investigational therapy HM97662 is making steady progress in its ongoing global Phase 1 clinical trial. Following the selection of a target indication, the company plans to expand clinical development, positioning HM97662 as a novel therapeutic option for small-cell lung cancer (SCLC)―a malignancy with significant unmet medical need. With its unique mechanism of action and promising preclinical data, HM97662 holds potential to address treatment gaps in the current SCLC landscape.

HM100714, a selective HER2 inhibitor, demonstrated significant tumor burden reduction and survival benefit in animal models of brain and leptomeningeal metastases with HER2 alterations following oral administration. During the treatment period, EGFR inhibition-related toxicity was not observed, highlighting its favorable safety profile. In addition, the candidate exhibited robust antitumor efficacy in Enhertu-resistant model, suggesting its potential to overcome the limitations of existing HER2-targeted small-molecule therapies.

HM100760, a MAT2A inhibitor, demonstrated strong antitumor activity in xenograft models of MTAP-deleted lung cancer cell lines when combined with a PRMT5 inhibitor. MAT2A inhibition reduces intracellular levels of S-adenosylmethionine (SAM), a key molecule involved in cellular function and growth, which in turn leads to partial suppression of PRMT5 activity. This mechanism underlies the synergy observed in the combination therapy, demonstrating superior antitumor efficacy over monotherapy, while maintaining a favorable safety profile. These findings underscore the therapeutic potential of targeting MAT2A and PRMT5 in tandem for MTAP-deleted cancers.

HM101207, Hanmi’s SOS1 inhibitor, made its debut at this year’s AACR with first-time disclosures of its mechanism of action and pharmacological profile. The drug was recognized as a next-generation candidate with high target selectivity, crucial for use in combination therapies. In KRAS-mutated xenograft models, it showed superior antitumor efficacy when combined with a KRAS G12C inhibitor or MEK inhibitor, outperforming competitor drugs. HM101207 has the potential to address a broad spectrum of KRAS mutations and is expected to overcome resistance to existing KRAS G12C, RTK, or MAPK pathway inhibitors.

A Hanmi official commented, “Our AACR presentations this year highlight the future potential of our oncology pipeline. We will continue to showcase Hanmi’s global R&D capabilities, with upcoming data on rare diseases and metabolic disorders to be presented at the European Society of Endocrinology (ESE) in May and the American Diabetes Association (ADA) in June.”


■ Contact info:

 Official Websites: www.hanmipharm.com

  innovation@hanmi.co.kr, +82-2-410-0467