Tenofovir exalidex, a novel prodrug of tenofovir, appeared safe and well-tolerated in patients with hepatitis B, according to a presentation at The Liver Meeting 2017.
“The final results from this study have confirmed a clear way forward for developing TXL so that it can become a key component of future, successful combination treatments for HBV infection,” Tawesak Tanwandee, MD, associate professor of medicine and head of the division of gastroenterology in the department of medicine at Siriraj Hospital, Mahidol University in Bangkok, Thailand, told Healio.com/Hepatology. “This is important for patients, and those who treat them, because we need to have many treatment choices for this widespread, and complicated, disease.”
In a phase 2a study, Tanwandee and colleagues randomly assigned 10 patients with hepatitis B to receive oral doses of 5 mg, 10 mg, 25 mg, 50 mg or 100 mg of tenofovir exalidex (Contravir Pharmaceuticals). An additional two patients with hepatitis B received 300 mg of tenofovir disoproxil fumarate.
Data from the first day single doses of tenofovir exalidex showed that the drug was rapidly absorbed and eliminated, like results from the phase 1 study in healthy volunteers.
The range of Tmax values across cohorts was 2 to 2.81 per hour and 1.01 to 2.09 per hour for t1/2 values. Systemic exposures, AUC0- (2.34-420.86 per hour ng/mL) and Cmax (2.30-168.97), of tenofovir exalidex were dose-proportional.
According to the researchers, systemic exposure of parent drug and metabolite was low, which was consistent with a liver-targeted approach.