HUYABIO International Announces HBI-8000 and Nivolumab Combination Reduces the Risk of Disease Progression by 27% in Patients with Advanced Melanoma in Phase 3 Trial

• Oral HBI-8000 plus intravenous nivolumab demonstrated a statistically significant and clinically meaningful improvement in progression-free survival compared with nivolumab alone, reducing the risk of disease progression or death by 27%
  
  
• Median progression-free survival was 11.7 months with HBI-8000 plus nivolumab compared with 7.4 months with nivolumab alone
  
  
• The safety profile of HBI-8000 was consistent with experience from its use in more than 112,000 patients treated in other cancers
  
  
• If approved, HBI-8000 plus nivolumab could provide a new frontline combination treatment option for advanced melanoma that does not rely on dual immune checkpoint inhibitors

MADRID and SAN DIEGO, Oct. 22, 2026 /PRNewswire/ -- HUYABIO International today announced that oral HBI-8000 in combination with intravenous nivolumab reduced the risk of disease progression or death by 27% compared with nivolumab alone in a global Phase 3 trial involving patients with advanced melanoma.

The combination demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS), with median PFS of 11.7 months compared with 7.4 months for patients receiving nivolumab plus placebo. Together with its encouraging safety profile, the findings demonstrate the potential of HBI-8000 plus nivolumab to become an important new frontline treatment option for patients with advanced melanoma.

Data from the Phase 3 trial will be presented today in an oral Proffered Paper session at the European Society for Medical Oncology (ESMO) Congress 2026 by Nikhil Khushalani, M.D., Vice-Chair for the Department of Cutaneous Oncology at the H Lee Moffitt Cancer Center and Research Institute in Tampa, Florida.

Despite the dramatic impact of immunotherapy on patient outcomes in recent years, there is still an unmet need for new treatments that combine strong efficacy with greater convenience and acceptable tolerability. The combination of twice-weekly oral HBI-8000 with intravenous nivolumab offers a new approach that does not rely on dual immune checkpoint inhibitors, potentially reducing the risk of immune-related adverse reactions. 

HBI-8000 is a highly differentiated selective Class I histone deacetylase (HDAC) inhibitor, designed to boost the immune response against cancer cells through epigenetic modification. By modifying the tumor microenvironment from non-responsive ('cold') to responsive ('hot'), HBI-8000 has the potential to enhance the activity of anti-PD-1 checkpoint inhibitors such as nivolumab.

Dr. Khushalani, lead investigator for the study, said: "These results show, for the first time, that adding a selective HDAC inhibitor to anti-PD-1 therapy can improve treatment outcomes for patients with advanced melanoma. As a combination therapy that does not rely on dual immune checkpoint inhibition, the immunotoxicity profile is particularly significant given the risk of overlapping toxicities when two checkpoint inhibitors are used together. The fact that HBI-8000 is taken orally and has a predictable side-effect profile may offer advantages over dual checkpoint combinations currently in use."

Dr. Mireille Gillings, Founder and CEO of HUYABIO, said: "We are delighted to share these exciting results that demonstrate superior efficacy for advanced melanoma patients treated orally with HBI-8000. Immunotherapy has greatly improved clinical outcomes and now there is a new potential standard of care that extends progression free survival, minimizes immunotoxicity, and delivers better quality of life with greater convenience."

In the Phase 3 trial, which involved 404 patients across 15 countries, median PFS (mPFS) in the intention to treat (ITT) population was 11.7 months (95% CI: 7.3 – 21.1) with HBI-8000 plus nivolumab, compared with 7.4 months (95% CI: 4.5 to 10.1) for nivolumab plus placebo. The PFS hazard ratio (HR) was 0.73 (96% CI: 0.56 to 0.95; p=0.014), representing a 27% reduction in the risk of disease progression or death. PFS results favored HBI-8000 plus nivolumab across most prespecified subgroups. Overall survival (OS) data remain immature, with follow-up ongoing.

Adverse events associated with the HBI-8000 combination were consistent with the known safety profiles of the individual medicines. The incidence of Grade 3 and 4 treatment-related adverse events (TRAEs) was 54.8% in the HBI-8000 plus nivolumab arm and 17.9% in nivolumab plus placebo. The most common adverse events were diarrhea, nausea, cytopenia and fatigue. TRAEs were generally well-managed and the higher rate seen in the combination arm appeared consistent with the class effects of HDAC inhibition. Dose reductions of HBI-8000 were required in 38% of patients. 

Importantly, there was no increase in cases of adrenal insufficiency or hypophysitis, two immune-related adverse events that are often irreversible and have a higher incidence with dual checkpoint inhibition.

HUYABIO International – a San Diego-headquartered company with unrivalled access to Chinese biopharmaceutical innovations, including HBI-8000 – plans to share the new data with the US Food and Drug Administration. The company also intends to engage with potential commercial partners as it works to bring the treatment to patients globally.

A manuscript detailing full results of the Phase 3 trial of nivolumab with or without HBI-8000 is being submitted for peer review.

Details of the ESMO Congress 2026 presentation

Abstract Number: LBA54 - Primary Analysis of HBI-8000-303: A Randomized Phase 3 Trial of Nivolumab plus HBI-8000 or Placebo in Advanced Melanoma

Presenter: Nikhil I. Khushalani, Moffitt Cancer Center, Tampa, FL, USA

Proffered Paper Session Details: Friday, October 23 at 16:15 - 17:45 CET in Barcelona Auditorium - Hall 9

Media Contact:

[email protected]

About HUYABIO International
HUYABIO is the leader in accelerating the global development of novel biopharmaceutical product opportunities originating in China enabling faster, more cost-effective and lower-risk drug development in international markets. Through extensive collaboration with biopharmaceutical, academic and commercial organizations, it has built the largest China-sourced compound portfolio covering all therapeutic areas. With offices in the US, Japan, Europe, and China, the company has become a partner of choice to accelerate product development and maximize patient impact and value globally.

About HBI-8000
HBI-8000 (tucidinostat/chidamide) is potentially the best-in-class immunomodulator. It is a highly differentiated oral, Class I-selective histone deacetylase (HDAC) inhibitor with an immunomodulatory mechanism. Through epigenetic modification, HBI-8000 has anti-tumor activity and converts an immunologically "cold" tumor microenvironment "hot", thereby increasing responsiveness to checkpoint inhibitors. HBI-8000 is approved and has been prescribed to over 112,000 patients as monotherapy for the treatment of T-cell lymphoma in China (as Epidaza ®) and Japan (as HIYASTA®), and in combination with an aromatase inhibitor for breast cancer in China and Taiwan, and in combination with R-CHOP in diffuse large B-cell lymphoma in China.

About the Phase 3 HBI-8000-303 trial
HBI-8000-303 [NCT04674683] is a global multicenter, randomized, double-blind, placebo-controlled Phase 3 study comparing the efficacy and safety of HBI-8000 combined with nivolumab to placebo combined with nivolumab in patients with unresectable or metastatic melanoma. The trial has completed enrollment and topline results were released in July 2026.

SOURCE HUYABIO International