A small vaccine developer favored by the UK government in Covid-19 touts a PhIII first in chikungunya
Before Valneva garnered the favor of the UK government as a potential supplier of Covid-19 vaccines, the French biotech prided itself on being the first company to bring a chikungunya vaccine into Phase III.
It now has positive pivotal results to back up the breakthrough therapy designation the FDA granted just weeks ago.
There are currently no approved jabs to prevent chikungunya virus infection despite decades of R&D efforts, a fact that underscores just how arduous traditional vaccine development can be, particularly for neglected tropical disease. In a absence of a major commercial market, the US government and NGOs such as CEPI have deployed various grants and incentives to spur on a small crew of academics and industry players, with Merck, via its acquisition of Themis, claiming a spot in that race.
It’s not just the honor and first-mover advantage that’s at stake. If Valneva succeeds in bringing its vaccine to market before anyone else, it would be eligible to receive a priority review voucher that, at last count, could sell for $100 million.
In a trial that enrolled 4,115 adults across the US, the vaccine — VLA1553 — met the primary endpoint by inducing protective CHIKV neutralizing antibody titers in 98.5% of volunteers 28 days after a single shot.
“The seroprotection rate result of 98.5% exceeded the 70% threshold (for non-acceptance) agreed with the FDA,” the company wrote in a statement. “The seroprotective titer was agreed with the FDA to serve as a surrogate of protection that can be utilized in a potential FDA submission of VLA1553 under the accelerated approval pathway.”
The vaccine offered “equally high” seroprotection rates and neutralizing antibody titers among elderly participants as younger adults, the company noted.
A look at 3,082 of the participants for safety also turned up no concerns, and most side effects were more or less expected — such as fever and headache, fatigue and myalgia.
What’s next? Investigators are still waiting for the six-month safety data to complete the final analysis, with results expected within the next half-year. There’s a separate trial ongoing to test the lot-to-lot manufacturing consistency.
Valneva designed VLA1553 as a single-dose, live attenuated vaccine that can offer long-term protection.
While Themis had pointed to a Phase III study for its chikungunya candidate as early as 2019, the pandemic appears to have thrown those timelines out the window. The new owners at Merck have since scrapped the Covid-19 shot, but kept the chikungunya shot — V184 — which was developed on the same measles virus vector. It shows up as part of the Phase II pipeline on its website.
Moderna is also developing an antibody against chikungunya, a mosquito-borne virus that can cause fever, joint pain and in rare cases, death.