US-based biopharmaceutical company ContraVir Pharmaceuticals has started a Phase lla trial comparing its CMX157 to tenofovir DF (TDF), marketed by Gilead Sciences as Viread to treat chronic hepatitis B (HBV).
The company has started screening for the trial that will enrol 60 treatment-naïve patients with chronic HBV infection.
The trial will compare sequentially escalating doses of CMX157, starting at a 5mg daily CMX157 dose compared to a 300mg daily dose of TDF, the standard daily dose of Viread.
During the trial, ten patients per cohort will receive four weeks of a once-daily dose of either 5mg, 10mg, 25mg, 50mg or 100mg of CMX157, and two patients per cohort will receive 300mg of TDF, the standard dose of Viread.
The trial is expected to end by the last quarter of this year.
ContraVir Pharmaceuticals CEO James Sapirstein said: "This is a significant inflection point for ContraVir, as the Phase lla study we've just commenced will be the first evaluation of the antiviral activity of CMX157 compared to Viread in hepatitis B patients.
"We're highly encouraged by the pharmacokinetic profile demonstrated so far in the Phase lb study, which showed detectable CMX157 levels at 5mg once daily, the lowest dose tested.
"Considering our animal data that shows a high degree of liver targeting and laboratory data showing superior potency of CMX157 against HBV in vitro, these preliminary results suggest the potential of CMX157 to be dosed lower than Viread, and at the same or lower dose than tenofovir alafenamide, Gilead's 'TAF'."
The Data Safety Monitoring Board (DSMB) has conducted an independent review of the safety, tolerability and pharmacokinetic profile of CMX157 from the three completed dosing groups of ContraVir's ongoing Phase Ib safety study in healthy volunteers.
Aside from recommending initiation of the Phase IIa trial, the DSMB also recommended continuation of the Phase Ib, which is now past its midpoint with the final two dosing groups 50 and 100 mg remaining.
The company noted that similar to the Phase lb trial, an initiation of each higher dose cohort in the Phase lla trial will follow review of the data from the previous cohort, and there will be another DSMB review between the 25mg and 50mg CMX157 cohorts.