Phase 1 Trial Begins for Immunotherapy Vaccine for Persistent Prostate Cancers

Phase 1 Trial Begins for Immunotherapy Vaccine for Persistent Prostate Cancers

An open-label, multicenter Phase 1 clinical trial has begun to evaluate the safety and immunogenicity of Panacea Pharmaceuticals’ PAN-301-1, a nanoparticle immunotherapy vaccine that targets HAAH-positive cancer cells in patients with persistent prostate cancer.

The first patient has been dosed, and participants are being enrolled in Alabama, California, Nebraska, and South Carolina.

HAAH, which stands for human aspartyl (asparaginyl) β-hydroxylase, is a protein required for fetal development, but its expression is silenced at birth. Studies have reported, however, that some cancers are able to express HAAH, and it participates in cancer cell growth, motility, and invasiveness. The protein is found in more than 20 types of cancer, and its expression is associated with poor prognosis.

Its specificity to cancer cells has made it a target for therapies.

“HAAH provides a new potential treatment pathway for patients living with persistent prostate cancer, and with the enrollment of the first patient at our center, we are eager to understand the safety and immunogenicity for PAN-301-1 to address this unmet medical need in cancer diagnosis and treatment,” lead investigator Luke Nordquist, MD, of GU Research Network in Omaha, Neb., said in a press release.

PAN-301-1 consists of a nanoparticle with hundreds of copies of an HAAH fragment. It induces an HAAH-specific antibody response and stimulates immune cells to target the protein.

In preclinical studies, the vaccine significantly inhibited tumor growth and metastasis, and it improved survival in mice and rats. There also were fewer side effects than with current cancer therapies, the release said.

The Phase 1 trial, designed to assess the vaccine’s safety, will enroll up to 18 patients with biochemically relapsed prostate cancer (their PSA levels increased after their last treatment regimen). Patients will receive PAN-301-1 injections every 21 days using an escalation-dose scheme to determine the optimal dosage for a Phase 2 trial.

“At Panacea, we have created a promising new vaccine therapy drug candidate that targets a specific and novel cancer-relevant marker, overcoming self-tolerance, yet avoiding autoimmune-like side effects of check-point inhibitors throughout our pre-clinical studies,” said Hossein A. Ghanbari, PhD, president, chief executive officer, and chief science officer at Panacea Pharmaceuticals. “The initiation of the Phase I PAN-301-1 serves as a starting point for utilizing HAAH in treatment to prevent the recurrence of cancer. We are excited to explore this new targeted biological pathway in cancer.”