PDS Biotech’s lead candidate, PDS0101, targets cancers associated with the human papillomavirus (HPV). PDS0101 combines the utility of the Versamune® platform with a proprietary mix of HPV16 antigens, the most virulent high-risk HPV type and by far the most prevalent in patients with HPV-associated cancers.
Approximately 43,000 patients are diagnosed with HPV-associated cancers each year, a number unlikely to be impacted in the next decade by the increased use of HPV preventive vaccines – given that the time from initial HPV infection to cancer diagnosis is often measured in decades. Nearly all of the HPV-related cancer patients that PDS0101 might treat in the coming years are already infected with HPV16.
Men and women are both impacted by HPV-associated cancers, but in strikingly different ways. In women, HPV infection most often leads to cervical, anal or vulvar cancer. While most men who develop HPV-associated cancer are diagnosed with oropharynx cancer, which affects the head and neck.
In a Phase 1 open-label, dose-ranging study, PDS0101 was evaluated for safety, tolerability and immunogenicity. Three groups of participants – each receiving 3 doses of either 1 mg, 3 mg or 10 mg 21 days apart – were evaluated over 133 days. The study demonstrated excellent translation of the mechanism of action from preclinical models to humans resulting in a unique ability to induce high levels of active tumor-targeting CD8+ killer T-cells in vivo in circulating blood within 14 days of treatment.
Based on the results of this clinical study, PDS Biotech determined that the 3 mg dosage offered the optimal mix of efficacy and safety. As a result, this dose was selected to be used in the ongoing Phase 2 PDS0101 clinical studies. PDS0101 was well-tolerated with toxicity limited to low-grade injection site reactions, most of which cleared within 7-10 days. NCT Number: NCT02065973
A post-hoc retrospective analysis demonstrated observed clearance of the CIN (lesion regression) in 80% of evaluable patients with complete regression in 60% of evaluable patients across the three tested doses as early as 1-3 months after treatment. These results were remarkably positive given that the vast majority of the treated population were infected with multiple high-risk HPV genotypes.
In partnership with Merck & Company and the National Cancer Institute (NCI) and MD Anderson Cancer Center, PDS Biotech is studying PD0101 in three Phase 2 clinical studies in advanced head and neck cancer, HPV-related advanced cancer, and cervical cancer respectively. Two of the three Phase 2 trials combine PDS0101 with the current standard of care treatment to evaluate if the addition of PDS0101 improves the efficacy of treatment.