Disappointing results for iluzanebart come shortly after Vigil Neuroscience struck a buy-out deal with Sanofi, but analysts say the outcome is unsurprising and shouldn’t affect the deal.
Two weeks after agreeing to be bought out by Sanofi, Vigil Neuroscience’s monoclonal antibody iluzanebart failed a Phase II study for a rare brain disorder and its development is being discontinued.
While noting good safety, tolerability and pharmacokinetics, Vigil said that iluzanebart showed “no beneficial effects on biomarker or clinical efficacy endpoints” in the Phase II IGNITE trial and concurrent natural history study called ILLUMINATE. Vigil had been pursuing accelerated approval for the antibody but hadn’t provided an update from the FDA in some time.
In a note to investors Wednesday morning, William Blair analysts said they were “not surprised” by the results, given that in buying Vigil, Sanofi did not get iluzanebart along with the rest of the company. Instead, the drug will go back to Amgen, the drug’s original licensor. Vigil launched back in 2020 with Amgen’s backing and ex-Amgen assets in its pipeline.
“We are disappointed on the IGNITE miss given early promising signals,” the William Blair analysts wrote, pointing to earlier testing results that showed pharmacological activity, but also noted that they’d had questions on bioavailability and reproducibility of the trial’s results. The results shouldn’t affect the deal with Sanofi, according to the analysts.
Iluzanebart, a monoclonal antibody TREM2 agonist, was being developed by Vigil for adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP), a rare, progressive brain disease that can lead to personality changes, loss of muscle function, and develop into dementia.
“While this is not the data outcome we hoped to see for our iluzanebart program and our patients . . . we believe our efforts and the data collected from the IGNITE clinical trial and ILLUMINATE natural history study have increased awareness and provided a deeper understanding of ALSP,” Vigil President and CEO Ivana Magovčević-Liebisch said in a statement announcing the results.
Sanofi agreed to buy Vigil in late May for about $470 million, with the hopes of bulking up its neuroscience pipeline. Central to the deal was Vigil’s other TREM2 agonist, VG-3927, aimed at neurodegenerative diseases such as Alzheimer’s.
Iluzanebart’s failure is another ding for a TREM2 space that has already seen a recent high-profile failure. Last November, Alector’s TREM2 antibody failed its own Phase II study for Alzheimer’s disease, triggering layoffs. In 2017, AbbVie paid $200 million for the global option to develop and commercialize the antibody.
