Schaaf, David

Importance The incidence of human papillomavirus type 16 (HPV16–positive) recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) is rising. Approved therapies offer a durable response to a minority of patients. Objective To determine the efficacy and safety of a therapeutic HPV16-targeted immunotherapy, PDS0101, in combination with pembrolizumab in participants with HPV16-positive R/M HNSCC, with separate evaluation of immune checkpoint inhibitor (ICI)–naive and ICI-resistant cohorts. Design, Setting, and Participants VERSATILE-002 was a phase 2, open-label, multicenter nonrandomized clinical trial conducted at 26 oncology centers from March 29, 2021, to May 15, 2025, across the US, UK, and Ireland using the Simon 2-stage optimal design. Efficacy analyses were performed on modified intent-to-treat (mITT) population; safety analyses included all participants who received 1 or more doses. Eighty-eight participants with histologically confirmed R/M HPV16-positive HNSCC were enrolled, of whom 87 (98.9%) received treatment and composed the safety population. Seventy five (85.2%) were in the mITT population used for efficacy analyses, of whom 53 (70.7%) were ICI-naive with a programmed cell death ligand 1 combined positive score of 1 or greater and 22 (29.3%) were ICI-resistant. Exposures Pembrolizumab (200 mg, intravenously, every 3 weeks for up to 35 cycles) plus subcutaneous PDS0101 (5 scheduled doses per protocol). Main Outcomes and Measures The primary end point was objective response rate (ORR) per the Response Evaluation Criteria in Solid Tumors , version 1.1, by a masked independent central reviewer. Secondary end points included progression-free survival (PFS), median overall survival (mOS), and safety, with exploratory end points of duration of response, disease control rate, and response rates by programmed cell death ligand 1 status. Results Of the 75 patients in the mITT population, the mean (SD) age was 64.0 (8.3) years; 4 individuals (5%) were female and 71 (95%) were male; and 2 individuals (3%) were Asian, 1 (1%) was Black, 5 (7%) were Hispanic, and 71 (95%) were White. Among 53 ICI-naive participants in the mITT cohort, ORR by the central reviewer was 34.0%, median PFS was 5.3 months (95% CI, 2.10-9.00), and mOS was 39.3 months (95% CI, 23.90 to not evaluable). Among 22 ICI-resistant patients in the mITT cohort, no objective responses were observed and the primary end point (ORR by central reviewer) was not met, but mOS was 14.8 months (95% CI, 8.50-26.00). The treatment was well tolerated, with 13.8% experiencing grade 3 or higher treatment-related adverse events. Conclusions and Relevance The results of this nonrandomized clinical trial suggest that PDS0101 plus pembrolizumab showed antitumor activity in ICI-naive HPV16-positive R/M HNSCC, with favorable safety, response rates, and survival outcomes. The findings support further evaluation in a first-line setting. Trial Registration ClinicalTrials.gov Identifier: NCT04260126

6037 Background: The incidence of HPV-associated head and neck squamous cell carcinoma (HNSCC) continues to rise with over 90% of cases being driven by HPV16. Median overall survival (OS) with pembrolizumab in first-line recurrent/metastatic (R/M) HNSCC is 12.3 months in subjects with CPS ≥1, 10.8 months for CPS ≥1-19, and 14.9 months for CPS ≥20. There is an urgent need to improve survival rates in the growing population of HPV16-positive R/M HNSCC. PDS0101 (Versamune HPV) is an investigational T cell stimulating immunotherapy that unleashes a potent, durable attack against HPV16-positive cancers and is being studied in combination with pembrolizumab. Preliminary results were presented at ASCO 2023. (Price KAR, et al. ASCO 2023. Abstract 6012). Methods: VERSATILE-002 is a single-arm phase 2 study evaluating PDS0101 and pembrolizumab for first-line HPV16-positive R/M HNSCC with CPS ≥1. Subjects received pembrolizumab 200 mg IV Q3W with PDS0101 1 mL SC administered concurrently during Cycles 1, 2, 3, 4, and 12 and pembrolizumab alone for all other Cycles up to Cycle 35 (approx. 2 years). The primary study endpoint is confirmed objective response rate (ORR) per RECIST 1.1. Secondary endpoints include progression-free survival (PFS), OS, and safety. Results: The median follow-up is 18.4 months (range 0.2-42.7 months). The efficacy population consists of 53 subjects: 32 (60%) with CPS ≥1-19 and 21 (40%) with CPS ≥20. The median OS for subjects with CPS ≥1 is 30 months (95% CI 23.9, NE). For the CPS ≥1-19 subgroup, the median OS is 29.5 months (95% CI 15.3, NE). For the CPS ≥20 subgroup, the median OS is 39.3 months (95% CI 18.4, NE). Confirmed response rates by investigator assessment are shown in the Table. Twenty-three subjects are still on study: 3 on treatment and 20 in long-term follow-up. No new safety signals have emerged. The most common TRAEs are injection site reactions, fatigue, headache, and pruritus. Only 19% of subjects experienced Grade ≥3 TRAEs. No subject had a Grade 5 TRAE. Conclusions: These data represent one of the most extended follow-up periods to date of subjects receiving an HPV16-targeted therapy for HPV16-positive R/M HNSCC. The PDS0101 and pembrolizumab combination is well tolerated and has demonstrated deep and durable clinical responses. Median OS is promising in light of historic expectations, both overall and relative to PD-L1 subgroup, and remains durable with continued follow up. The results support further evaluation in a randomized phase 3 study with OS as the primary endpoint. Clinical trial information: NCT04260126 . Summary of results. CPS ≥1-19 (N=32) CPS ≥20 (N=21) CPS ≥1 (N=53) ORR, % 28.1 47.6 35.8 DCR, % 75.0 81.0 77.4 Median DOR, months (95 % CI) 21.8 (4.2, NE) NE (5.6, NE) 21.8 (11.5, NE) Median PFS, months (95% CI) 5.1 (2.4, 8.1) 14.1 (2.1, NE) 6.3 (3.5, 9.0) Median OS, months (95% CI) 29.5 (15.3, NE) 39.3 (18.4, NE) 30.0 (23.9, NE)

TPS6111 Background: Human papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) has surpassed cervical cancer as the most common HPV-related cancer in the US, with the majority being caused by HPV16. Persistent expression of HPV16 oncoproteins E6 and E7 by host genome may promote HNSCC. HPV16-positive HNSCC may be associated with poor clinical outcomes in the recurrent/metastatic (R/M) setting. PDS0101 (Versamune HPV) is an HPV16-immunotherapy that generates a potent, targeted T cell attack against HPV16 E6 & E7. In a Phase 2 study, PDS0101 plus pembrolizumab has shown encouraging safety and survival benefit in patients with HPV16-positive R/M HNSCC. (Weiss J et al. ESMO 2024. Poster 879P. NCT04260126). Methods: VERSATILE-003 is a global Phase 3, randomized, controlled, open-label study evaluating PDS0101 plus pembrolizumab vs. pembrolizumab in patients with HPV16-positive R/M HNSCC with PD-L1 positive disease (CPS ≥1). Key eligibility criteria include age ≥18-years-old, histologically- or cytologically-confirmed diagnosis of R/M HNSCC with primary tumor location of oropharynx, oral cavity, hypopharynx, or larynx and no prior systemic anticancer treatment in the R/M setting, HPV16 tumor positivity (centrally tested), PD-L1 positivity defined as CPS ≥ 1 using FDA-approved PD-L1 IHC 22C3 pharmDx kit, and measurable disease based on RECIST 1.1 confirmed by blinded independent central review (BICR). Patients will be randomized 2:1 to receive pembrolizumab 200 mg IV Q3W with PDS0101 1 mL SC administered concurrently during Cycles 1, 2, 3, 4, and 12 (investigational arm), or pembrolizumab 200 mg IV Q3W alone (control arm). The primary objective is to compare overall survival (OS) between the investigational and control arms. Secondary objectives include objective response rate (ORR), disease control rate (DCR), duration of response (DOR), and progression-free survival (PFS) using RECIST 1.1 and assessed by BICR. Exploratory objectives include tumor response assessed by investigator and by irRECIST, PFS2, quality of life as assessed by EQ-5D, QLQ-C30, and QLQ H&N35, and assessment of ctHPVDNA. Updated enrollment data will be provided. Clinical trial information: NCT06790966 .

6012 Background: Up to 70% of oropharyngeal cancers in the US are reported to be HPV-mediated with most caused by HPV16 infection. First line treatment for patients with unresectable, recurrent or metastatic (R/M) disease is pembrolizumab with or without chemotherapy, but most patients eventually experience disease progression. PDS0101 is a novel, investigational HPV16-targeted immunotherapy that stimulates a potent, targeted T cell attack against HPV16-positive cancers. Methods: VERSATILE-002 (NCT04260126) is an open-label, non-randomized, Simon 2-stage study evaluating the combination of PDS0101 and pembrolizumab in subjects with HPV16-positive R/M HNSCC in 2 cohorts: ICI-naïve and ICI-refractory. All subjects receive pembrolizumab IV Q3W with PDS0101 SC administered concurrently during Cycles 1, 2, 3, 4, and 12 (max 5 doses). The primary endpoint of the study is confirmed Best Overall Response per RECIST 1.1. Herein we update the safety, PFS, and OS data for the ICI-naïve subjects. Results: Forty-eight subjects who received at least one cycle of combination therapy (safety population) had a median age of 62.5 (range 45 – 83), were 93.8% male, 93.8% White, and 62.5% ECOG 0. Among this population, the median overall treatment duration in months was 3.5 (range 0.0 – 19.5). The median number of PDS0101 doses was 4 (range 1 – 5); 56.3% received 4 doses and 22.9% received 5 doses. The median number of pembrolizumab doses was 5 (range 1 – 29); 27.1% received ≥10 doses. Efficacy was evaluated in 34 subjects (47.1% with CPS ≥20) who had assessment of tumor response following treatment (efficacy population). Tumor reduction (maximum percent change from baseline) was seen in 23 (67.6%) subjects. Nine subjects (26.5%) had confirmed response including 1 CR and 8 PR, 15 subjects had SD (44.1%), and 9 subjects had PD (26.5%). One subject was not evaluable (2.9%). The median PFS was 10.4 months (95% CI 4.2, 15.3). Among the safety population, median overall survival was non-estimable due to the ongoing survival status of study subjects. The estimated 12-month OS rate was 87.1%. Thirty-three (68.5%) subjects had mild or moderate (Grade 1 or 2) PDS0101-related TEAE (TRAE); the most common were fatigue and injection site reactions (ISRs). Only 3 subjects (6.3%) had Grade 3 TRAEs: fatigue, ISR, blood alkaline phosphatase increased, and hyperglycemia. No subjects had Grade 4 or 5 TRAE. No subject came off study due to toxicity. Conclusions: PDS0101 with pembrolizumab is well tolerated in this ICI naïve R/M HPV-associated HNSCC population. Median PFS was 10.4 months which compares favorably to published median PFS of 2-3 months for approved ICIs when used as monotherapy in patients with similar PD-L1 levels. The estimated 12-month OS of 87.1% is promising compared to published results of about 36-50%. These results justify a confirmatory randomized, controlled study. Clinical trial information: NCT04260126 .

AbstractObjectivesCompare healthcare resource utilization (HCRU) and costs between patients prescribed opioids (RxOP) and those who were not (NoRxOP) during an emergency department (ED) or inpatient visit.MethodsRetrospective cohort analysis was performed (January 2006 to September 2010). Continuously eligible RxOP patients in ED/inpatient settings (January 2007 to September 2009) were included if age was ≥ 12 years by initial prescription date (or random date between first ED/inpatient admission and September 30, 2009 [NoRxOP patients]).Healthcare resource utilization and costs for 12 months after initial prescription were compared. Univariate descriptive analyses were performed for baseline and outcome variables and compared using appropriate tests. Risk adjustment compared HCRU between RxOP and NoRxOP cohorts for the postindex period.ResultsOf 27,599 eligible patients, RxOP patients (n = 18,819) were younger, less likely to be male, more likely to reside in southern United States and to have Preferred Provider Organization health plans, and had lower comorbidity index scores, compared with NoRxOP patients (n = 8,780). RxOP patients were less likely to have nonpain‐related comorbidities and more frequently diagnosed with pain‐related comorbidities.Unmatched and propensity‐matched RxOP patients experienced higher HCRU and costs in all subcategories (total, inpatient, outpatient ED, physician, pharmacy, other outpatient settings). Opioid abuse frequency was low in patients with common diagnoses/procedures within 3 months before initial prescription (0.48%). Average time to abuse was < 1 year (201 days).ConclusionMost patients were prescribed opioids initially during ED/inpatient visits and incurred higher HCRU than those not prescribed opioids. Among those with diagnosed opioid abuse after initiating opioids, time to diagnosis was rapid (range: 14 to 260 days) for patients with common diseases and procedures.