Eisai secures USD388M deal for Chinese cancer drug Hetronifly in Japan

JAPAN—Japanese pharmaceutical powerhouse Eisai has entered into a major oncology licensing agreement with Shanghai-based Henlius Biotech, valued at up to USD388 million.

The deal grants Eisai exclusive rights to develop and commercialize Henlius’ cancer treatment Hetronifly (serplulimab) throughout Japan.

Under the terms of the agreement, Eisai will provide an initial upfront payment of USD 75 million to secure development and commercialization rights for the drug.

Hetronifly is an anti-programmed cell death protein 1 (PD-1) monoclonal antibody that has already received regulatory approval in China for treating several solid tumour types.

Beyond the initial payment, Henlius is eligible for additional milestone payments tied to regulatory achievements and sales performance, totalling up to USD 80 million and USD 233 million, respectively.

The Chinese biotech company will also receive double-digit royalty payments on all sales in the Japanese market.

Eisai has highlighted that Hetronifly has a unique binding mechanism distinct from existing anti-PD-1 antibodies available in Japan.

This distinctive feature could potentially give the drug a competitive advantage in an increasingly crowded market segment.

The timing of Eisai’s deal coincides with significant regulatory progress for Hetronifly in Europe.

On February 5, the European Commission moved toward approving the drug in combination with carboplatin and etoposide as a first-line treatment for extensive-stage small cell lung cancer (ES-SCLC).

Intas Pharmaceuticals previously secured European rights to Hetronifly in 2023.

Notably, the therapy achieved a significant milestone by becoming the first anti-PD-1 drug globally to gain approval for frontline ES-SCLC treatment following a favorable decision from the UK Medicines and Healthcare Products Regulatory Agency.

To ensure Hetronifly meets Japanese regulatory requirements and market expectations, Henlius is currently conducting multiple clinical trials in Japan.

Among these studies is a Phase II trial (NCT06812260) specifically evaluating the drug’s effectiveness in ES-SCLC patients.

Drawing on results from these Japanese trials, along with data from Phase III studies that supported approvals in China and Europe, Henlius intends to submit a regulatory application in Japan during 2026.

The company also plans to initiate a Japanese clinical trial examining Hetronifly’s use in perioperative gastric cancer treatment while maintaining its role as the marketing authorization holder.

The PD-1 therapy market represents a substantial commercial opportunity for pharmaceutical companies worldwide.

MSD’s blockbuster drug Keytruda (pembrolizumab) generated USD31.7 billion in global sales during fiscal year 2025.

Similarly, Bristol Myers Squibb’s Opdivo (nivolumab) generated USD10 billion in worldwide revenue in 2025, an 8% year-over-year increase.

Despite the success of single-target PD-1 therapies, the pharmaceutical industry faces growing concerns about tumour resistance developing from prolonged use of these treatments.

This challenge has prompted companies to explore multi-target approaches designed to overcome acquired resistance mechanisms.

The industry has shown particular interest in bispecific antibodies that simultaneously target both PD-1 and vascular endothelial growth factor (VEGF).

Major pharmaceutical players, including AbbVie, Bristol Myers Squibb, Pfizer, and MSD, have committed substantial resources to this approach through multi-billion-dollar partnerships and acquisitions.

However, some industry voices have raised concerns about this convergent strategy.

The CEO of oncology-focused biotech Candel Therapeutics cautioned in an interview with Pharmaceutical Technology that the industry’s focus on identical targets risks creating redundancy and potentially hampering innovation efficiency across the sector.