Three-Drug Regimen Boosts Outcomes in HPV-Related Cancers

A novel three-drug combination bested standard-of-care regimens for patients with human papillomavirus-related cancers, according to phase 2 study results.

The novel drug combination of PDS0101 plus M9241 and bintrafusp alfa is improving outcomes in patients with human papillomavirus (HPV)-related cancers, according to findings from a phase 2 clinical trial reported by PDS Biotechnology, the manufacturer of PDS0101, in a press release.

The trial, which was conducted at the Center for Cancer Research at the National Cancer Institute (located near Washington, D.C.), involved 51 patients with advanced HPV-positive anal, cervical, head and neck, vaginal and vulvar cancers who were not previously treated with a checkpoint inhibitor or whose cancer did not respond or stopped responding to a checkpoint inhibitor. All patients enrolled in the study previously received chemotherapy, and most (90%) received radiation.

In the 29 patients whose disease did not respond to checkpoint inhibition (checkpoint refractory) and were given the three-drug combination, the average overall survival (time from treatment until death of any cause) was 29 months. Historically, this group of patients has had an average overall survival of three to four months, PDS Biotechnology reported in the press release.

Eight patients with checkpoint refractory disease received the optimal dose of PDS0101 plus M9241 and bintrafusp alfa. Of those patients, the objective response rate (percentage of patients whose disease shrinks as a result of treatment) was 63% (five patients). With the current standard of care, the average objective response rate tends to be less than 10%.

In patients who never received checkpoint inhibition (checkpoint inhibition naïve), 75% were still alive at a follow-up of 27 months, so the average overall survival has not yet been reached. Prior data showed that these patients typically have an average overall survival of seven to 11 months.

The objective response rate for checkpoint naïve patients was 88% — much higher than the average of 25%, which is seen with Food and Drug Administration (FDA)-approved checkpoint blockades for patients with HPV-related cancers.

“The expanded data continue to demonstrate the durability and tolerability of the PDS0101-based triple combination therapy in advanced HPV-positive cancers, an extremely challenging population of refractory and previously untreatable HPV-positive patients,” said Dr. Frank Bedu-Addo, president and CEO of PDS Biotech, in the press release.

Slightly less than half (48%) of patients experienced moderate treatment-related side effects from the three-drug regimen, and 4% experienced severe side effects. For patients receiving checkpoint inhibition plus chemotherapy for HPV-related cancers, approximately 70% experienced moderate side effects, according to the release.

Of note, PDS0101 is also being studied in combination with Keytruda (pembrolizumab) for patients with HPV-related head and neck cancer.

“We are pleased to see the continued consistency in the data with each update and we look forward to meeting with the FDA to discuss the registrational pathway,” concluded Bedu-Addo.

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