Effects of Food, Gastric Acid Reduction, and Strong CYP3A Induction on the Pharmacokinetics of Tasurgratinib, a Novel Selective Fibroblast Growth Factor Receptor Inhibitor.

We conducted this three-part study in healthy subjects to investigate the pharmacokinetics of tasurgratinib (orally available selective inhibitor of fibroblast growth factor receptor 1-3) and M2 (its major metabolite) under different conditions. In Part A, subjects received tasurgratinib 35 mg either fed with a high-fat meal or fasted. In Parts B and C, subjects received tasurgratinib 35 mg alone or with either rabeprazole (acid-reducing agent) 20 mg (Part B) or rifampin (strong CYP3A inducer) 600 mg (Part C). Primary endpoints were maximum concentration (Cmax), and areas under the plasma concentration-time curve to time of last quantifiable concentration (AUC(0-t)) and extrapolated to infinite time (AUC(0-inf)). Forty-two subjects were enrolled, 14 each into Parts A, B, and C. In Part A, administration of tasurgratinib with a high-fat meal resulted in 33% reduction in Cmax and ∼23% reduction in AUC(0-t) and AUC(0-inf) of tasurgratinib, and 47% reduction in Cmax with ∼30% reduction in AUC(0-t) and AUC(0-inf) of M2. In Part B, co-administration of rabeprazole at steady state resulted in no/weak interaction with tasurgratinib (∼8% increase in AUC(0-t) and AUC(0-inf) without an effect on Cmax) and M2 (∼18% increase in AUC(0-t) and AUC(0-inf) without an effect on Cmax). In Part C, co-administration of rifampin at steady state resulted in a weak interaction with tasurgratinib (∼16% reduction in AUC(0-t) and AUC(0-inf)) and M2 (∼12% reduction in AUC(0-t) and AUC(0-inf)). Administration of tasurgratinib with a high-fat meal appeared to reduce systemic exposure of tasurgratinib, however co-administration with an acid-reducing agent or a CYP3A inducer had a minimal impact on pharmacokinetics.

Cochlear Gene Therapy for Sensorineural Hearing Loss: Current Status and Major Remaining Hurdles for Translational Success.

Sensorineural hearing loss (SNHL) affects millions of people. Genetic mutations play a large and direct role in both congenital and late-onset cases of SNHL (e.g., age-dependent hearing loss, ADHL). Although hearing aids can help moderate to severe hearing loss the only effective treatment for deaf patients is the cochlear implant (CI). Gene- and cell-based therapies potentially may preserve or restore hearing with more natural sound perception, since their theoretical frequency resolution power is much higher than that of cochlear implants. These biologically-based interventions also carry the potential to re-establish hearing without the need for implanting any prosthetic device; the convenience and lower financial burden afforded by such biologically-based interventions could potentially benefit far more SNHL patients. Recently major progress has been achieved in preclinical studies of cochlear gene therapy. This review critically evaluates recent advances in the preclinical trials of gene therapies for SNHL and the major remaining challenges for the development and eventual clinical translation of this novel therapy. The cochlea bears many similarities to the eye for translational studies of gene therapies. Experience gained in ocular gene therapy trials, many of which have advanced to clinical phase III, may provide valuable guidance in improving the chance of success for cochlear gene therapy in human trials. A discussion on potential implications of translational knowledge gleaned from large numbers of advanced clinical trials of ocular gene therapy is therefore included.