Poolbeg Pharma’s Phase 2a TOPICAL trial is investigating whether POLB 001 can prevent cytokine release syndrome in patients with relapsed/refractory multiple myeloma receiving bispecific antibody therapy.

Trial focuses on a common complication of immunotherapy

The trial, led by Dr Emma Searle, consultant haematologist at The Christie NHS Foundation Trust, is evaluating POLB 001 as a potential preventative treatment for cytokine release syndrome (CRS), an inflammatory reaction that can occur following cancer immunotherapies.

TOPICAL is recruiting approximately 30 patients with relapsed/refractory multiple myeloma who are receiving the approved bispecific antibody teclistamab. The first patient was dosed in July, while University College London Hospital (UCLH) has since been activated as the second clinical trial site. Additional UK sites are expected to join the study.

CRS is a recognised complication of bispecific antibody treatment. In the MajesTEC-1 study of teclistamab in relapsed/refractory multiple myeloma, CRS occurred in 72.1% of patients, with most cases being lower grade.

For patients receiving these therapies, however, the risk of CRS can affect where treatment is delivered. Monitoring requirements mean that patients may need to attend specialist cancer centres, potentially creating additional travel and access challenges.

Dr Emma Searle said: “Immunotherapy treatments are transforming survival rates for patients with difficult-to-treat blood cancers, but their use will continue to be restricted until we find a way to deliver them safely outside of specialist hospitals. Because of the risk of CRS, which can be dangerous, many patients can’t be treated near to home which is a real problem.”

POLB 001 aims to prevent CRS

POLB 001 is an orally delivered p38 MAP kinase inhibitor being developed by Poolbeg Pharma as a potential preventative therapy for cancer immunotherapy-induced CRS.

The TOPICAL study is designed to investigate the safety and efficacy of POLB 001, with particular focus on whether the treatment can reduce the incidence of CRS during step-up dosing with teclistamab. The study is open label and single arm.

The clinical rationale centres on managing CRS before it becomes a barrier to wider use of immunotherapy. Current approaches include step-up dosing and monitoring, with treatment available for patients who develop more significant reactions.

If POLB 001 can reduce the incidence or severity of CRS, it could potentially support a move towards delivering some bispecific antibody treatments in less specialised settings. That remains an investigational possibility, however, and the TOPICAL trial will need to demonstrate that the approach is safe and effective.

Interim data expected later this summer

Poolbeg said interim data from TOPICAL remains on track for late summer 2026, making the study one to watch as recruitment progresses.

The company has also reported strong interest from haematology investigators in participating in the trial. The study is being conducted with support from Accelerating Clinical Trials, while Johnson & Johnson is supplying teclistamab for the study at no cost to Poolbeg.

The timing also puts the trial in the spotlight ahead of Blood Cancer Awareness Month in September, providing an opportunity to highlight both multiple myeloma and the treatment-related complications that can accompany newer immunotherapies.

For patients, the potential significance of the research is ultimately less about the commercial opportunity around POLB 001 and more about whether managing CRS can help make effective cancer immunotherapies easier to deliver.