Thomas Marron, MD, PhD, on the Safety, Feasibility, and Immunogenicity of Neoantigen Peptide Vaccine PGV-001

Thomas Marron, MD, PhD, of the Icahn School of Medicine at Mount Sinai, spoke with CancerNetwork about the data and primary objectives of the phase 1 trial presented at the virtual AACR Annual Meeting investigating PGV-001, a neoantigen peptide vaccine, in a cohort of 15 patients.

Transcription:

This was a phase 1 trial and so the primary objectives were really threefold. First, we wanted to determine the safety and tolerability of the vaccine. We wanted to determine the feasibility of creating the vaccine both using our pipeline to identify neoantigens and then actually successfully synthesizing those peptides. And then finally, to find the immunogenicity of the vaccine.

The adjuvant space is a very tough space to look for actual clinical efficacy and so only with longer term follow up are we really going to be able to say anything about that, and we really would need larger trials to look at clinical efficacy, but that is obviously one of the secondary objectives.

But our primary objective, as far as determining the safety and tolerability, this was a very safe, well tolerated therapy. It does require a lot of visits, that was probably the most pressing adverse event, although I don’t think that we grade number of visits as an adverse event. But really, patients with only a few instances of injection site reactions and 1 patient had a low-grade fever, we really didn't have any other toxicity concern.

The vaccine was successfully synthesized for 13 patients and it was administered to 13 patients. All but 2 patients received all 10 vaccines really over the course of 6 months. There was 1 patient who only received 9 vaccines and another that received 7 vaccines. That patient actually, unfortunately at that point, had recurrent disease also with pretty aggressive biology.