Author: Ariana Pelosci
Source: www.cancernetwork.com

Fast track designation was granted to PDS0101 plus pembrolizumab, which is currently being assessed in the phase 2 VERSATILE study in patients with recurrent or metastatic human papillomavirus 16–positive head and neck cancer.

PDS0101 plus pembrolizumab (Keytruda) has been granted fast track designation by the FDA for patients with recurrent or metastatic human papillomavirus (HPV) 16–positive head and neck cancer, according to a press release from PDS Biotechnology.1

The combination is currently being investigated in the phase 2 VERSATILE-002 study (NCT04260126) in the aforementioned patient population. PDS0101 is a subcutaneous T cell HPV-specific immunotherapeutic that can encourage high levels of CD8-positive and CD-4 positive T cells. This is achieved by activating numerous immune pathways. These T cells have been observed to target different tumors that have occurred as a result of HPV16 infection.

“We are thrilled that the FDA has granted fast track designation for PDS0101 in combination with [pembrolizumab],” Frank Bedu-Addo, PhD, chief executive officer of PDS Biotech, said in the press release. “The HPV-associated head and neck cancer prevalence continues to rise, leaving this affected group with limited treatment options to date. Receiving this designation underscores the potential of the Versamune® platform and the need for a new therapy that may improve outcomes for those with this devastating disease.”

At the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting, results from the trial were presented.2 In stage 1 of the study, 17 patients were included who were checkpoint inhibitor naïve with 4 or more objective responses, and 21 patients were checkpoint inhibitor refractory with 2 or more objective responses. In stage 2, 37 patients were checkpoint inhibitor naïve with 14 or more total objective responses, and 20 were checkpoint inhibitor refractory with 5 or more total objective responses.

Patients were given 200 mg of pembrolizumab intravenously every 3 weeks, and PDS0101 during cycles 1 to 4 and 12. Continuation of pembrolizumab happened until disease progression, intolerance, or patients reached 35 cycles.

The response rate was 41% for those who received the combination. The 9-month progression-free survival rate was 55.2% (95% CI, 31.9%-78.4%) and the 9-month overall survival rate was 87.2% (95% CI, 70.4%–not estimable).

Initial efficacy data showed 19 patients who were checkpoint inhibitor naïve had a combined positive score (CPS) of over 1 and 7 patients had a CPS of over 20, and had an ECOG performance status of 0 to 1. Of these patients, 17 had imaging data; investigators reported an objective response in 41.2% of patients, 35.3% had stable disease, and 23.5% had progressive disease. Moreover, 76.5% of these patients had a complete response, partial response, or stable disease.

Patients received a median of 4 doses of PDS0101, with a median treatment duration of 2.2 months. The median number of doses of pembrolizumab received was 9.0 and the median duration of treatment was 5.9 months.

The safety population included 19 patients, 26.3% of whom had grade 3 treatment-emergent adverse effects (TEAEs). Additionally, none had grade 4 and 10.5% had grade 5 TEAEs.