Third cohort of Phase I melanoma trial approved

Approval has been granted for the third cohort of Prima BioMed’s Phase I clinical trial of IMP321 in combination with KEYTRUDA, being conducted in Australia. This cohort will recruit six patients with unresectable or metastatic melanoma.

Interim data from the first patient cohort, which were released at the end of last year, indicated that the 1 mg dose of IMP321 was safe and well tolerated. All six patients included in the first cohort had suboptimal response to KEYTRUDA as monotherapy and two had a partial or complete radiological tumour response according to immune related response criteria (irRC).

The second cohort, where patients were dosed with 6 mg of IMP231, further confirmed the safety profile of IMP321. In this cohort, all six study participants treated with KEYTRUDA and IMP321 at the higher dose did not experience any serious adverse reactions or dose limiting toxicity.

As a result of these data sets, the independent Drug Safety Monitoring Board (DSMB) has granted approval for the third cohort, which will assess IMP321 at 30 mg dose level. Safety will be evaluated as the primary endpoint and anti-tumour activity and immune response to the combination of IMP321 and KEYTRUDA as secondary endpoints.

Prima BioMed is a biotechnology company that develops immunotherapeutic products. Its lead product, IMP321, is an antigen presenting cell activator that is based on the LAG-3 immune control mechanism, which plays a role in the regulation of the T cell immune response.