The indane diastereoisomers, PH2 and PH5: divergence between their effects in delayed-type hypersensitivity models and a model of colitis
JOURNAL OF PHARMACY AND PHARMACOLOGY
Authors: Frankish, Neil H.; McHale, Brendan; Sheridan, Helen
Abstract
ObjectivesCompounds PH2 and PH5 are distereoisomers of novel indane compounds, synthesised as analogues of secondary metabolites of the fern, Onychium. In this study, we compare their effects on a variety of inflammatory models. MethodsIn an effort to extend our knowledge of their anti-inflammatory profile, we have investigated their activity in two models of delayed-type hypersensitivity (DTH); the methylated bovine serum albumin model (mBSA) and the oxazolone contact hypersensitivity (CHS) model, on IL2 release from Jurkat cells and in the dextran sulphate sodium (DSS) murine model of inflammatory bowel disease. Key findingsBoth diastereoisomers are equipotent in reducing paw swelling in the mBSA model and in inhibiting interleukin (IL) 2 release from Jurkat cells. They are equally ineffective in the oxazolone contact hypersensitivity model (CHS). Only the diastereoisomer, PH5, protects against DSS-induced colitis and of its two enantiomers, only the S,S-enantiomer, PH22, possesses this activity. PH2 is ineffective in the DSS model. ConclusionsThe results suggest that the beneficial effect of PH5, and its enantiomer PH22, in the DSS model is a consequence of an action on a target specific to the colitis model. The implications of such data suggest an unknown target in this disease model that may be exploited to therapeutic advantage.
Immunomodulation by Entinostat in Renal Cell Carcinoma Patients Receiving High-Dose Interleukin 2: A Multicenter, Single-Arm, Phase I/II Trial (NCI-CTEP#7870)
CLINICAL CANCER RESEARCH
Authors: Pili, Roberto; Quinn, David I.; Hammers, Hans J.; Monk, Paul; George, Saby; Dorff, Tanya B.; Olencki, Thomas; Shen, Li; Orillion, Ashley; Lamonica, Dominick; Fragomeni, Roberto S.; Szabo, Zsolt; Hutson, Alan; Groman, Adrienne; Perkins, Susan M.; Piekarz, Richard; Carducci, Michael A.
Abstract
Purpose: On the basis of preclinical data suggesting that the class I selective HDAC inhibitor entinostat exerts a synergistic antitumor effect in combination with high-dose IL2 in a renal cell carcinoma model by downregulating Foxp3 expression and function of regulatory T cells (Treg), we conducted a phase I/II clinical study with entinostat and high-dose IL2 in patients with metastatic clear cell renal cell carcinoma (ccRCC). Experimental Design: Clear cell histology, no prior treatments, and being sufficiently fit to receive high-dose IL2 were the main eligibility criteria. The phase I portion consisted of two dose levels of entinostat (3 and 5 mg, orally every 14 days) and a fixed standard dose of IL2 (600,000 U/kg i.v.). Each cycle was 85 days. The primary endpoint was objective response rate and toxicity. Secondary endpoints included progression-free survival and overall survival. Results: Forty-seven patients were enrolled. At a median follow-up of 21.9 months, the objective response rate was 37% [95% confidence interval (CI), 22%-53%], the median progression-free survival was 13.8 months (95% CI, 6.0-18.8), and the median overall survival was 65.3 months (95% CI, 52.6.-65.3). The most common grade 3/4 toxicities were hypophosphatemia (16%), lymphopenia (15%), and hypocalcemia (7%), and all were transient. Decreased Tregs were observed following treatment with entinostat, and lower numbers were associated with response (P = 0.03). Conclusions: This trial suggests a promising clinical activity for entinostat in combination with high-dose IL2 in ccRCC patients and provides the first example of an epigenetic agent being rationally combined with immunotherapy. (C) 2017 AACR.