ReViral raises $55M to run midphase RSV clinical trials

ReViral has raised $55 million (€47 million) to put a treatment for respiratory syncytial virus (RSV) infections through midphase trials. The series B round comes six months after ReViral completed a phase 2a evaluation of RSV fusion inhibitor RV521 in healthy volunteers. 

British biotech ReViral emerged from the phase 2a with data to support its theory that RV521 treats RSV infection by stopping the virus envelope from fusing with the host cell membrane. Other drug developers, including Gilead and Johnson & Johnson, are working on similar candidates in a belief they can improve on the disposition and safety of earlier experimental fusion inhibitors, thereby serving the unmet needs of the tens of millions of people who suffer RSV infections each year.

Now, ReViral has raised money to move toward the realization of this vision. New backers New Leaf Venture Partners and Novo Ventures co-led the round with the support of some of the investors that powered ReViral to its $21 million series A, including Andera Partners, OrbiMed and Brace Pharma Capital.

The series B tees ReViral up to expand its midphase development program. Phase 2a trials of RV521 in children and adults are in the works. An international, multisite pediatric trial is set to get going soon, with studies in adult stem cell transplant patients to follow further down the line.

Those studies will start the process of showing how RV521 performs in patients. The phase 2a that reported data earlier this year enrolled healthy volunteers and infected them intranasally with RSV to assess the viral-stopping power of RV521. Both trialed doses of RV521 statistically beat placebo in terms of reduction in viral load—the primary endpoint—and secondary measures such as total mucus weight and symptom score.

RELATED: British biotech ReViral hits goals in early RSV test

ReViral needs more data to confirm the effect but its early steps in the clinic have persuaded some VCs that RV521 will outperform the competition, and that the biotech can use the candidate as a launchpad for a broader attack on RSV. 

“We believe ReViral has a truly superior product candidate, and the company’s focus gives it the potential to build a franchise of RSV programs, eventually expanding into all the diseases associated with infection by this virus,” Isaac Manke, partner at New Leaf, said in a statement.