Nxera’s Partner Cancer Research UK Presents Data from Successfully Completed Phase 1 Clinical Trial of Cancer Immunotherapy Drug HTL0039732 at ESMO

• HTL0039732 (also known as NXE0039732) is Nxera’s novel oral EP4 antagonist with the potential to treat a wide range of cancers in combination with other immunotherapies
• HTL0039732, was found to be well-tolerated, confirmed target engagement and demonstrated encouraging early efficacy in two distinct tumor types when administered in combination use with atezolizumab
• Phase 1 trial met the key objectives and identified a dose for a Phase 2 expansion trial, which is now underway
• Cancer Research UK’s Centre for Drug Development is sponsoring and managing the ongoing Phase 1/2a clinical trial of HTL0039732

Tokyo, Japan and Cambridge, UK, 21 October 2025 – Nxera Pharma (“the Company” or “Nxera”; TSE: 4565) announces that its partner, Cancer Research UK, presented data from the successfully completed Phase 1 part of the ongoing Phase 1/2a clinical trial () of Nxera’s immunotherapy drug HTL0039732 (also known as NXE0039732) at the European Society for Medical Oncology Congress (ESMO) 2025 being held 17-21 October 2025 in Berlin, Germany.

The first-in-human trial is evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics and anti-tumor activity of HTL’732 as a monotherapy (n=13) and in combination with the checkpoint inhibitor atezolizumab (n=22), in patients with advanced solid tumors that were resistant or refractory to standard therapy.

Key data from the Phase 1 portion of the trial presented at ESMO in an ePoster included:

• The primary objectives of this Phase1 study were safety and the determination of a RP2D to support progression into the expansion phase.
• HTL’732 was well tolerated with no grade 4/5 treatment-related adverse events and no dose limiting toxicities in monotherapy or in combination. Grade 3 treatment-related adverse events occurred in 14% of combination patients (3 of 22), similar to established atezolizumab monotherapy data, demonstrating an encouraging profile for combination treatment and suggesting that safety data may be a differentiating factor among drugs with the same mechanism of action
• Confirmed partial responses to the combination of HTL’732 and atezolizumab – as determined by RECIST criteria and showing >30% tumor reduction – were seen in two patients. One with metastatic renal cell cancer (ccRCC) who had experienced previously experienced progressive disease on checkpoint inhibitor therapy and a second patient with microsatellite stable colorectal cancer (MSS-CRC), a disease subgroup that does not benefit from monotherapy checkpoint inhibitors. We were encouraged to see partial responses in 1 out of 2 ccRCC patients (50%) and 1 out of 11 MSS-CRC patients (~9%) in this Phase 1 study.
• Based on the data presented the recommended Phase 2 dose for progression into cohort expansion studies was selected as 160mg QD in combination with atezolizumab

The Phase 2a trial expands four cohorts of patients from MSS CRC, gastric or gastroesophageal junction (GOJ) adenocarcinoma, clear cell renal cell carcinoma, and metastatic castration-resistant prostate cancer backgrounds. The first patient was dosed in the Phase 2a portion of the trial in .

Cancer Research UK’s Centre for Drug Development is sponsoring and managing the trial, which is led by Chief Investigator Dr. Bristi Basu, University of Cambridge, and Co-Chief Investigator Dr. Debashis Sarker, King’s College London. The trial’s lead site is Addenbrooke’s Hospital, Cambridge, and it is open for recruitment across several other sites across the Experimental Cancer Medicine Centre (ECMC) network.

Nxera Pharma holds a license to the results generated.

Dr. Alastair Brown, SVP, Future Therapeutic Strategy at Nxera Pharma, commented: “We are encouraged by the robust safety profile and promising results from the completed Phase 1 study of our novel EP4 antagonist HTL0039732 in cancer patients whose tumors are resistant or refractory to standard therapy. Although this was a small trial, we are pleased to see excellent tolerability alongside clinical and pharmacodynamic activity, that all compares very favourably with other drugs acting with the same mechanism. Radiological responses in otherwise immunotherapy-resistant tumors demonstrate a potential to improve on current treatments and these data have enabled our partner CRUK to advance HTL’732 into the Phase 2 expansion part of the trial in a more-defined group of solid tumors. We believe data to date keeps HTL’732 on track for the potential to be best-in-class amongst other drugs with this mechanism of action and look forward to sharing further updates as the trial progresses.”

Details of the ePoster:

• Title: Cancer Research UK first-in-human (FIH) phase I/IIa trial of the prostaglandin E2 (PGE2) receptor 4 (EP4) antagonist HTL0039732 (HTL) as monotherapy and in combination with immunotherapy in patients with advanced solid tumours
• Authors: B. Basu et al.
• Abstract number: 948P ( for link to abstract on ESMO website)
  
  
  
  

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About HTL0039732 (NXE0039732)

HTL’732 is an oral small molecule drug candidate designed using Nxera’s NxWave™ platform to block signalling through the prostaglandin E2 (PGE2)-type prostanoid receptor 4 (EP4). PGE2 acts in the tumor microenvironment to trigger cancer cells to evade the immune system. Targeting EP4 to block the effects of PGE2 increases the ability of the immune system to detect and control cancer cells and makes HTL0039732 a potential candidate to treat patients with cancers that generally do not respond well to current immunotherapies.

About Nxera Pharma

Nxera Pharma is a technology powered biopharma company, in pursuit of new specialty medicines to improve the lives of patients with unmet needs in Japan and globally.

We have built an agile, new-generation commercial business in Japan to develop and commercialize innovative medicines, including several launched products, to address this high value, large and growing market and those in the broader APAC region.

Behind that, and powered by our unique NxWave™ discovery platform, we are advancing an extensive pipeline of over 30 active programs from discovery through to late clinical stage internally and in partnership with leading pharma and biotech companies. This pipeline of potentially first- and best-in-class candidates is focused on addressing major unmet needs in some of the fastest-growing areas of medicine across obesity and metabolic disorders, neurology/neuropsychiatry and immunology and inflammation.

Nxera employs approximately 400 talented people at key locations in Tokyo and Osaka (Japan), London and Cambridge (UK), Basel (Switzerland) and Seoul (South Korea) and is listed on the Tokyo Stock Exchange (ticker: 4565).

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About the Cancer Research UK Centre for Drug Development

Cancer Research UK has an impressive record of developing novel treatments for cancer. The Cancer Research UK Centre for Drug Development has been pioneering the development of new cancer treatments for 30 years, taking over 170 potential new anti-cancer agents into clinical trials in patients. Six of these new agents have made it to market, including temozolomide for brain cancer, abiraterone for prostate cancer and rucaparib for ovarian cancer. Two other drugs are in late development Phase 3 trials. Thirteen agents remain in active development with the potential to reach the market. It currently has a portfolio of 16 projects in preclinical development, Phase 1 or early Phase 2 clinical trials.  

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