In an ongoing, open label, phase I/IIa clinical trial, patients with measurable or fully resected solid tumors were treated with a personalized tumor lysate dendritic cell vaccine that was prepared using a novel, scalable, and rapid method requiring only 1 mg of tumor and 120 mL of patient’s blood. The vaccine was well-tolerated. Among 31 patients with residual disease, 2 had complete response (both had failed prior therapy and received no concurrent therapy), 4 had partial response, and 6 had stable disease. In the adjuvant arm, 6 of 13 patients remained disease-free at a median follow-up of 22.5 months.

INTRODUCTION: Tumor vaccines use various strategies to generate immune responses, commonly targeting generic tumor-associated antigens. The tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine is produced from DC loaded with autologous tumor antigens, creating a patient-specific vaccine. Here, we describe initial phase I/IIa trial results. METHODS: This trial includes patients with any stage solid tumors, ECOG 4months life-expectancy. A personalized vaccine is created using 1mg of tumor and 120ml blood (to isolate DC). Primary vaccination series (PVS) is four monthly inoculations. Patients are followed per standard of care (SOC). Endpoints include safety and tumor response (RECIST v1.1). RESULTS: 44 patients were enrolled and vaccinated consisting of 31 late stage patients with residual/measurable disease, and 13 disease-free patients after SOC therapies. While 4 patients progressed before completing the PVS, 12/31 (39%) demonstrated clinical benefit (2 complete responses, 4 partial responses, 6 stable disease). In the adjuvant setting, 46% of late stage patients remain disease free at a median of 22.5months. CONCLUSIONS: The TLPLDC vaccine is scalable, generates a personalized DC vaccine, and requires little autologous tumor tissue and few DC. The vaccine is safe, with primarily grade 0-2 toxicities, and nearly 40% clinical benefit rate in varied tumors, warranting further study. TRIAL REGISTRATION: ISRCTN81339386, Registered 2/17/2016.

Author Info: (1) San Antonio Military Medical Center, 3551 Roger Brooke Dr., Ft. Sam Houston, TX 78234, United States. Electronic address: garth.s.herbert.mil@mail.mil. (2) Womack Army Medical Center

Author Info: (1) San Antonio Military Medical Center, 3551 Roger Brooke Dr., Ft. Sam Houston, TX 78234, United States. Electronic address: garth.s.herbert.mil@mail.mil. (2) Womack Army Medical Center, 2817 Reilly Rd, Ft. Bragg, NC 28310, United States. (3) San Antonio Military Medical Center, 3551 Roger Brooke Dr., Ft. Sam Houston, TX 78234, United States. (4) San Antonio Military Medical Center, 3551 Roger Brooke Dr., Ft. Sam Houston, TX 78234, United States. (5) San Antonio Military Medical Center, 3551 Roger Brooke Dr., Ft. Sam Houston, TX 78234, United States. (6) Madigan Army Medical Center, 9040 Jackson Ave, Ft. Lewis, WA 98431, United States. (7) San Antonio Military Medical Center, 3551 Roger Brooke Dr., Ft. Sam Houston, TX 78234, United States. (8) Womack Army Medical Center, 2817 Reilly Rd, Ft. Bragg, NC 28310, United States. (9) Orbis Health Solutions, 111 Smith Hines Rd, Greenville, SC 29607, United States. (10) Orbis Health Solutions, 111 Smith Hines Rd, Greenville, SC 29607, United States. (11) Clemson University Biological Sciences Dept, 101 Barre Hall, Clemson, SC 29634, United States. (12) Orbis Health Solutions, 111 Smith Hines Rd, Greenville, SC 29607, United States. (13) Cancer Vaccine Development Program, 110 E. Houston St, San Antonio, TX 78205, United States.

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