PDS Biotechnology announced its cancer vaccine candidate PDS0101 met the threshold for efficacy in the second stage of a Phase II trial in head and neck cancer.
PDS Biotech confirmed that PDS0101 achieved the threshold of objective response as per investigator assessment in stage two of the Phase II VERSATILE-002 trial (NCT04260126). The study is investigating PDS0101 in combination with Merck’s anti-PD-1 therapy Keytruda (pembrolizumab) for the treatment of unresectable, recurrent or metastatic human papillomavirus (HPV)16-positive head and neck cancer.
PDS0101 is a liposomal-based therapeutic vaccine intended to help the immune system respond to HPV16-infected tumour cells. It is injected subcutaneously alone or combined with other immunotherapies and cancer treatments.
Keytruda, an immune checkpoint inhibitor, has been a blockbuster oncology drug that recently garnered its 34th approval from the US Food and Drug Administration (FDA).
Reaching the efficacy threshold
PDS0101 met the efficacy threshold when 14 of 54 patients in the immune checkpoint inhibitor (ICI) naïve arm experienced either complete response or partial response on two consecutive scans, confirming objective response. Additional patients have yet to undergo imaging evaluation, and the company said it will continue to monitor efficacy and safety.
As per the RECIST 1.1 standard patients are considered to have achieved an objective response at tumour shrinkage of 30% or more. In VERSATILE-002, a confirmed objective response for the primary endpoint requires two consecutive scans nine to 12 weeks apart, rather than one.
The primary endpoint in the VERSATILE-002 study is the best overall response of confirmed complete response (CR) or confirmed partial response (PR). The key secondary endpoints are progression-free survival (PFS), overall survival (OS) at 12 and 24 months, safety, and tolerability.
“Achieving the efficacy threshold in VERSATILE-002 is an important milestone for the Company, especially as it has been achieved ahead of the full efficacy evaluation for this cohort,” said Dr Lauren Wood, chief medical officer of PDS Biotech. “With our Phase II trial near completion, and our planned global Phase III confirmatory randomized, controlled trial, VERSATILE-003, actively advancing, we believe we are closer to our goal of providing a well-tolerated, safe and effective therapy for those who suffer from head and neck cancer, a critical unmet medical need.”
PDS Biotech’s Phase III plans
VERSATILE-003 will evaluate the safety and efficacy of PDS0101 in combination with Keytruda versus Keytruda monotherapy. The combination will be evaluated in ICI-naïve patients with recurrent or metastatic HPV16-positive head and neck squamous cell carcinoma (HNSCC) and was granted fast track designation by the FDA in June 2022. The planned primary endpoints for VERSATILE-003 are OS and PFS. In preparation for the trial, PDS Biotech plans to submit an amended Investigational New Drug (IND) application to the FDA in Q3 2023.
