Highlights

  • AdAlta reported 50% response rate in high-dose cohort of BZDS1901-treated patients.
  • 20% complete response rate, with tumours becoming undetectable in some patients.
  • Total of 14 advanced mesothelioma patients treated with Generation 2 therapy
  • Overall response rate reached 42.9%, exceeding typical treatment benchmarks
  • Updated safety protocols enabled higher dosing with manageable side effects

AdAlta Ltd (ASX:1AD) shares closed flat at AUD 0.0040 on 1 April 2026, despite touching an intraday high of AUD 0.0050. The steady close followed the release of a clinical update highlighting encouraging outcomes from ongoing trials of its investigational cancer therapy, BZDS1901.

Encouraging Clinical Responses in Advanced Cancer Patients

The company reported updated results from investigator-initiated trials evaluating BZDS1901 in patients with advanced mesothelioma. These patients had previously failed to respond to, or relapsed after, standard treatments such as chemotherapy or immunotherapy.

A total of 14 patients have now been treated with the Generation 2 version of the therapy. Among those receiving the highest doses, five out of ten patients experienced tumour shrinkage of more than 30%, representing a 50% overall response rate.

In addition, tumours became undetectable in two patients, corresponding to a 20% complete response rate. In one case, tumours measuring approximately 5 cm prior to treatment were no longer detectable following therapy and remained so over an extended follow-up period.

Response Rates Exceed Existing Treatment Benchmarks

The company highlighted that current second-line treatment options for advanced mesothelioma typically deliver response rates ranging from 11% to 29%, with complete responses considered uncommon.

By comparison, the outcomes observed with BZDS1901 suggest higher response levels, with overall response rates across the broader cohort reaching 42.9%. These results indicate a notable improvement relative to existing therapies in this patient population.

Furthermore, more than a quarter of patients demonstrated continued tumour shrinkage over time, providing evidence of sustained therapeutic activity.

Survival Outcomes and Ongoing Patient Monitoring

Among the treated patients, several have demonstrated extended survival durations. Four patients have survived beyond 12 months, while additional patients remain alive but have not yet reached the 12-month evaluation point.

The median overall survival has not yet been reached, with multiple patients continuing under observation. These outcomes are being monitored as part of ongoing follow-up within the clinical trials.

Safety Profile Supports Higher Dose Exploration

The updated results also included observations on safety, with revised management protocols enabling administration of higher doses.

No dose-limiting toxicities were reported in the extension cohort at higher dose levels. Additionally, no severe cases of cytokine release syndrome were observed.

One serious neurological event was reported but resolved quickly following treatment, with the patient subsequently achieving a complete response. Overall, the safety profile is considered manageable within the current trial framework.

Advancing Clinical Development Pathway

The positive outcomes from the trial are supporting further exploration of higher dosing levels in future studies. Planning is underway for an additional extension cohort, which may include up to five more patients, subject to agreement with the clinical partner.

AdAlta Ltd, through its subsidiary AdCella, continues to focus on advancing BZDS1901 toward broader clinical development, including potential expansion into Western markets.

The therapy targets mesothelin, a protein commonly associated with aggressive cancers such as mesothelioma, lung cancer, and certain gynaecological cancers.

Broader Development Portfolio

AdAlta is developing a pipeline of cell and protein-based therapies aimed at addressing unmet needs in oncology and other diseases. Its lead program, BZDS1901, represents a first-in-class CAR-T cell therapy designed for solid tumours.

Beyond oncology, the company is also progressing other assets, including treatments targeting fibrotic diseases and infectious conditions, as part of its broader strategy.

What This Means for Investors?

While the share price remained unchanged on the day, the clinical update highlights continued progress in AdAlta’s lead therapy program. The observed tumour response rates, survival outcomes, and safety profile support ongoing development and potential future studies.

With further data collection underway and additional cohorts being planned, investors are likely to monitor how these clinical results evolve and contribute to the company’s development pathway.