Versamune HPV Plus Pembrolizumab Maintains Encouraging OS in Recurrent/Metastatic HPV16+ HNSCC

Kirk Shepard, MD

Treatment with Versamune HPV (PDS0101) in combination with pembrolizumab (Keytruda) continued to demonstrate durable median overall survival (OS) in patients with human papillomavirus (HPV)16–positive recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) in the phase 2 VERSATILE-002 trial (NCT04260126), according to a news release issued by PDS Biotechnology Corporation.¹

At a data cutoff of May 17, 2024, with approximately 6 months of additional follow-up, checkpoint inhibitor–naive patients (n = 53) demonstrated a median OS of 30.0 months (95% CI, 19.7-not evaluable) which is consistent with prior data presented by the company on May 9, 2024. Additionally, 27 patients who were censored remained alive and were awaiting their next clinical assessment at the data cutoff; 6 withdrew consent for further follow-up; 2 were lost to follow-up; and 18 patients died.

Notably, in May 2024, first-line treatment with the combination met the trial’s primary end point of best overall response (BOR) in HPV16-positive recurrent or metastatic HNSCC.2 The combination elicited a BOR of 34% in patients who were naive to checkpoint inhibitors and had a PD-L1 combined positive score (CPS) of at least 1 (n = 53) and a BOR of 48% in patients with a PD-L1 CPS of at least 20 (n = 21).

Full data from the May 17, 2024, data cutoff are expected to be announced in the third quarter of 2024.¹

“In recurrent and/or metastatic HNSCC, objective response rate and progression-free survival have generally not translated into increased survival, and under current standards of care survival rates are well established to be less than 18 months,” Kirk Shepard, MD, chief medical officer of PDS Biotech, stated in a press release.¹ “We believe that our VERSATILE-002 clinical trial and triple combination trial provide us with the critical survival information needed to effectively design the statistical primary end point in our planned phase 3 trial.”

The novel investigational “inside-outside” mechanism of the Versamune HPV immunotherapy aims to disrupt a tumor’s internal defenses while producing potent, targeted killer T cells to attack the tumor externally.¹

The open-label, multicenter VERSATILE-002 study enrolled patients aged 18 and older with histologically confirmed, recurrent, metastatic, or persistent HNSCC and a confirmed HPV16 infection.3 These patients must have a PD-L1 CPS of at least 1. In the checkpoint inhibitor–naive cohort, patients were not allowed to have had any prior immunological therapy, and in the pretreated cohort, patients were required to have received prior treatment with checkpoint inhibitors, either as monotherapy or in combination. This included at least 2 doses or a minimum of 6 weeks on treatment and documented and radiologically confirmed clinical progression or recurrence.

Inclusion criteria for all patients consisted of recurrent and/or metastatic disease per RECIST 1.1 criteria; adequate organ function; an ECOG performance status of 0 or 1; and recovery from toxicities associated with prior radiation.

Exclusion criteria included previous treatment with a checkpoint inhibitor or another stimulatory or co-inhibitory T-cell receptor–directed agent that was discontinued due to grade 3 or higher adverse effects; treatment with anticancer therapy within 30 days of enrollment; active central nervous system metastases and/or carcinomatosis meningitis; prior allogeneic hematopoietic stem cell transplantation within the past 5 years; active autoimmune disease requiring systemic treatment in the past 2 years; and a history of non-infectious pneumonitis requiring steroids or current pneumonitis.

At 0.5 mL during cycles 1, 2, 3, 4, and 12, patients were treated with 2 subcutaneous injections of Versamune HPV. Patients also received 200 mg of pembrolizumab before the first injection of Versamune HPV and during cycles 5 to 11 and 13 to 35.

PDS Biotech continues to investigate treatment with Versamune HPV in a 3-arm registrational trial for the first-line treatment of patients with HPV16-positive recurrent/metastatic HNSCC.¹

References

1. PDS Biotech provides data update from ongoing VERSATILE-002 phase 2 clinical trial in head and neck cancer. News release. PDS Biotechnology Corporation. June 12, 2024. Accessed June 12, 2024. https://pdsbiotech.com/index.php/investors/news-center/press-releases/press-releases1/131-2024-news/927-iotechrovidesatapdatefromngoing00220240612
2. PDS Biotech VERSATILE-002 phase 2 clinical trial meets primary study endpoints in first line recurrent/metastatic HPV16-positive head and neck cancer. News release. PDS Biotechnology Corporation. May 9, 2024. Accessed June 12, 2024. https://pdsbiotech.com/index.php/investors/news-center/press-releases/press-releases1/131-2024-news/918-iotech002hase2linicalrialeetsrim20240509
3. Study of PDS0101 and pembrolizumab combination I/O in subjects with HPV16 + recurrent and/​or metastatic HNSCC (VERSATILE002). ClinicalTrials.gov. Updated May 21, 2024. Accessed June 12, 2024. https://clinicaltrials.gov/study/NCT04260126