p53-Reactive T Cells Are Associated with Clinical Benefit in Patients with Platinum-Resistant Epithelial Ovarian Cancer After Treatment with a p53 Vaccine and Gemcitabine Chemotherapy

Autor: Don J. Diamond, Joshua D. I. Ellenhorn, Mihaela C. Cristea, Lucille Leong, Julie Kilpatrick, Raechelle Tinsley, Sharon P. Wilczynski, Melissa Eng, Christopher Ruel, Nicola Hardwick, Ferdynand Kos, Robert J. Morgan, Weimin Tsai, Vincent Chung, Paul Frankel, Teodora Kaltcheva
Rok vydání: 2017
Předmět:
Zdroj: Clinical cancer research : an official journal of the American Association for Cancer Research. 24(6)
ISSN: 1557-3265
Popis: Purpose: To conduct a phase I trial of a Modified Vaccinia Ankara vaccine delivering wild-type human p53 (p53MVA) in combination with gemcitabine chemotherapy in patients with platinum-resistant ovarian cancer. Experimental Design: Patients received gemcitabine on days 1 and 8 and p53MVA vaccine on day 15, during the first 3 cycles of chemotherapy. Toxicity was classified using the NCI Common Toxicity Criteria and clinical response assessed by CT scan. Peripheral blood samples were collected for immunophenotyping and monitoring of anti-p53 immune responses. Results: Eleven patients were evaluated for p53MVA/gemcitabine toxicity, clinical outcome, and immunologic response. Toxicity: there were no DLTs, but 3 of 11 patients came off study early due to gemcitabine-attributed adverse events (AE). Minimal AEs were attributed to p53MVA vaccination. Immunologic and clinical response: enhanced in vitro recognition of p53 peptides was detectable after immunization in both the CD4+ and CD8+ T-cell compartments in 5 of 11 and 6 of 11 patients, respectively. Changes in peripheral T regulatory cells (Tregs) and myeloid-derived suppressor cells (MDSC) did not correlate significantly with vaccine response or progression-free survival (PFS). Patients with the greatest expansion of p53-reactive T cells had significantly longer PFS than patients with lower p53-reactivity after therapy. Tumor shrinkage or disease stabilization occurred in 4 patients. Conclusions: p53MVA was well tolerated, but gemcitabine without steroid pretreatment was intolerable in some patients. However, elevated p53-reactive CD4+ and CD8+ T-cell responses after therapy correlated with longer PFS. Therefore, if responses to p53MVA can be enhanced with alternative agents, superior clinical responses may be achievable. Clin Cancer Res; 24(6); 1315–25. ©2018 AACR.
Databáze: OpenAIRE