Vorinostat and hydroxychloroquine improve immunity and inhibit autophagy in metastatic colorectal cancer
Metrics: PDF 1965 views | HTML 2543 views | ?
Sukeshi Patel1, Vincent Hurez1, Steffan T. Nawrocki1, Martin Goros1, Joel Michalek1, John Sarantopoulos1, Tyler Curiel1, Devalingam Mahalingam1
1Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
Devalingam Mahalingam, email: email@example.com
Keywords: vorinostat, hydroxychloroquine, colorectal cancer, autophagy, immunity
Received: May 06, 2016 Accepted: June 30, 2016 Published: July 23, 2016
Hydroxychloroquine (HCQ) enhances the anti-cancer activity of the histone deacetylase inhibitor, vorinostat (VOR), in pre-clinical models and early phase clinical studies of metastatic colorectal cancer (mCRC). Mechanisms could include autophagy inhibition, accumulation of ubiquitinated proteins, and subsequent tumor cell apoptosis. There is growing evidence that autophagy inhibition could lead to improved anti-cancer immunity. To date, effects of autophagy on immunity have not been reported in cancer patients. To address this, we expanded an ongoing clinical study to include patients with advanced, refractory mCRC to evaluate further the clinical efficacy and immune effects of VOR plus HCQ. Refractory mCRC patients received VOR 400 milligrams orally with HCQ 600 milligrams orally daily, in a 3-week cycle. The primary endpoint was median progression-free survival (mPFS). Secondary endpoints include median overall survival (mOS), adverse events (AE), pharmacodynamic of inhibition of autophagy in primary tumors, immune cell analyses, and cytokine levels. Twenty patients were enrolled (19 evaluable for survival) with a mPFS of 2.8 months and mOS of 6.7 months. Treatment-related grade 3–4 AEs occurred in 8 patients (40%), with fatigue, nausea/vomiting, and anemia being the most common. Treatment significantly reduced CD4+CD25hiFoxp3+ regulatory and PD-1+ (exhausted) CD4+ and CD8+ T cells and decreased CD45RO-CD62L+ (naive) T cells, consistent with improved anti-tumor immunity. On-study tumor biopsies showed increases in lysosomal protease cathepsin D and p62 accumulation, consistent with autophagy inhibition. Taken together, VOR plus HCQ is active, safe and well tolerated in refractory CRC patients, resulting in potentially improved anti-tumor immunity and inhibition of autophagy.
All site content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 License.