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Replies to post #217468 on Biotech Values
(ENTA) Re: MoAs of RSV treatments in development
Most RSV treatments in development, including the one about which you posted, are fusion inhibitors. RSV fusion inhibitors work by preventing viral entry into a host cell, but they don’t work on every at-risk cell. Once a given cell is infected with RSV, a fusion inhibitor cannot stifle the viral activity in that cell, which leaves a residual disease burden that may compromise the overall efficacy of the drug.
ENTA’s EDP-938 is not a fusion inhibitor, but rather an N-protein inhibitor. An N-protein inhibitor disrupts RSV’s viral-replication machinery inside an infected cell in an analogous way to the MoAs of HCV DAAs.
The above is a consequential distinction for ENTA’s RSV program, IMO.
03/02/18 2:41 PM
10/23/18 10:46 AM
Enanta Pharmaceuticals…today announced that dosing has begun in a Phase 2a study to evaluate the safety, pharmacokinetics and antiviral activity of multiple doses of orally administered EDP-938 against respiratory syncytial virus infection in a human challenge study.
…up to 114 healthy adult subjects will be randomized into 1 of 3 arms (1:1:1) and will be dosed for 5 days. All subjects will be infected with RSV-A Memphis 37b virus, and approximately 76 subjects will receive EDP-938 and 38 subjects will receive placebo. Arm 1 will receive placebo, Arm 2 will receive a single 500 mg loading dose of EDP-938 followed by 300 mg BID, and Arm 3 will receive a daily 600 mg dose.
…EDP-938 is the only N-protein inhibitor in development today… we are targeting preliminary Phase 2a results in calendar 3Q19.
EDP-938 Phase 1 Results
The Phase 1 randomized, double-blind, placebo (PBO)-controlled, first-in-human study was conducted to evaluate the safety, tolerability, and pharmacokinetics (PK) of single- and multiple- (7 days) ascending doses (SAD: 50 - 800 mg and MAD: 100 - 600 mg once daily and 300 mg twice daily) and food effect (FE) of EDP-938 in healthy subjects. In the SAD phase, 50 subjects [EDP-938 (n=38) and PBO (n=12)] were enrolled into 6 dose cohorts; in the MAD phase, 40 subjects [EDP-938 (n=30) and PBO (n=10)] were enrolled into 5 dose cohorts.
Overall, no safety concerns have been reported in 68 healthy subjects receiving a broad range of single and multiple doses of EDP-938. Headache was the most frequently reported AE during the SAD and MAD phases. There were no SAEs, and AEs were of mild intensity, with none leading to study drug discontinuation.
EDP-938 was rapidly absorbed and exposure increased with increasing single and multiple dosing, resulting in a PK profile suitable for once or twice daily oral dosing regardless of food. In the MAD phase, half-life ranged from 12.9 to 17.6 hours, and at doses comparable to those under study in the Phase 2a trial, mean trough levels were approximately 30x higher than the EC90 of EDP-938 against RSV-infected human cells.
