Jessica L Campf1, John W Myers1, Guy T Clifton1, Diane F Hale1, Tommy A Brown1, Timothy J Vreeland2, Robert Hi Andtbacka3, Adam C Berger4, James W Jakub5, Jeffrey J Sussman6, Alicia M Terando7, Mark B Faries8. 1San Antonio Military Medical Center, 2University of Texas MD Anderson Cancer Center, 3Huntsman Cancer Institute, 4Thomas Jefferson University Kimmel Cancer Center, 5Mayo Clinic, 6University of Cincinnati Cancer Institute, 7The Ohio State University Cancer Center, 8The Angeles Clinic
Objective: The autologous tumor lysate, particle loaded, dendritic cell (TLPLDC) vaccine has been previously shown to be safe and immunogenic while producing objective tumor responses in a variety of metastatic patients. Here, we present the pre-specified interim results of a randomized, double blind phase IIb trial (NCT02301611) assessing the TLPLDC vaccine to prevent recurrences in high-risk melanoma patients.
Methods: Stage III & IV resectable melanoma patients were identified prior to definitive surgery and consented for tumor collection. Patients were re-consented for treatment and randomized 2:1 (vaccine:placebo). TLPLDC or placebo vaccines were initiated within 3 months of completion of standard of care (SoC) therapies. Intradermal inoculations were given at 0, 1, 2, 6, 12, and 18 months. Patients were followed for recurrence per SoC, and the primary endpoint is 2 year disease-free survival (DFS). The interim analysis was pre-specified at 6 months from the 120th randomization. Survival analysis was performed on the intention-to-treat (ITT) and per treatment (PT) populations. The latter excludes early recurrences during the primary vaccine series (PVS) (up to 6 months).
Results: The trial randomized 120 patients (Vaccine = 83, Placebo = 37). There were no clinicopathologic or treatment-related differences between the groups except for median age (Vaccine = 65 years, Placebo = 57 years, p=0.02) and ulceration (Vaccine = 11 patients, Placebo = 10 patients, p=0.02). There was a 3:1 ratio of stage III:IV in both groups. Study-wide, only 33% of patients experienced treatment-related adverse events (AEs) with 98.6% being grade 1-2. There were no serious AEs or immune-mediated AEs.
In the ITT analysis, there was no difference in recurrence (Vaccine = 56.6%, Placebo = 54.1%, p=0.65) at a median follow-up of 11.9 months.
In the PT analysis, there was a trend toward decreased recurrences in the TLPLDC arm (Vaccine = 29.4%, Placebo = 43.3%, p=0.07) at a median follow-up of 12.6 months.
Conclusion: The TLPLDC vaccine is safe with minimal toxicity. Among patients completing the PVS period (6 months), there is a strong trend toward fewer recurrences in the TLPLDC arm. This benefit will be further elucidated after completion of the analysis of 2 year DFS. Also, this early data provides encouraging results indicating that a phase III trial for efficacy may be warranted.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 94614
Program Number: MSS02
Presentation Session: Full-Day Military Surgical Symposium – Basic Science/Quality Improvement Presentations
Presentation Type: MSSPodium