The US Food and Drug Administration (FDA) has placed a clinical hold on patient enrollment and dosing in Bellicum Pharmaceuticals’ ongoing Phase I/II dose-escalation clinical trial analysing BPX-601 in patients with previously treated metastatic pancreatic or prostate cancer.

Bellicum noted that the FDA’s action comes after a pancreatic cancer patient died in the trial that was reported to the agency.

The patient death has been classified as unrelated to BPX-601 and rimiducid by the clinical investigator and Bellicum.

BPX-601 is a GoCAR-T product candidate, which has the company’s inducible co-activation domain, inducible MyD88/CD40 (iMC).

iMC has been designed to provide a boost to T cell proliferation and persistence, immunomodulatory cytokine production and facilitate the CAR-T to override key immune inhibitory mechanisms such as PD-1 and TGF-beta.

The candidate is being analysed as a treatment for pancreatic and prostate tumours expressing prostate stem cell antigen (PSCA).

The company intends to work with the agency to address its queries and fulfil the requirements for the trial resumption.

In August, Bellicum reported interim data from a dose-escalation trial of BPX-601 in patients with relapsed/refractory metastatic pancreatic cancer.

Results showed that the first four patients treated with BPX-601 followed by repeat rimiducid dosing demonstrated evidence of rimiducid-mediated CAR-T cell activation.

The latest development will not affect Bellicum’s plans to begin enrolment in the Phase I/II clinical trial of a dual switch GoCAR-T, BPX-603, in patients with HER2+ solid tumours by the year-end.

Designed to be more efficacious CAR-T cell products, Bellicum’s GoCAR-T product candidates, BPX-601 and BPX-603 can potentially override key immune inhibitory mechanisms.

In 2017, Bellicum began dosing in its Phase I clinical trial (BP-012) of BPX-601 for the treatment of patients with non-resectable pancreatic adenocarcinoma.