Validation of the anti-FcRn mechanism by more advanced rivals seems to have been partly behind Immunovant’s bold decision to halt enrolment in its phase I myasthenia gravis trial of IMVT-1401 at a mere 15 patients. Keenly awaited results from the Ascend MG trial presented yesterday certainly look competitive, although the very small patient number is hard to ignore. The study, which was intended to recruit 21, tested two dosages of the subcutaneously delivered project in a total of 10 patients, with five given placebo. The primary endpoint, mean improvement on a symptom scale called MG-ADL versus placebo, was met with statistical significance, while IMVT-1401 also managed to impressively drive down IgG, thought to be a driver of the autoimmune condition. The project’s subcutaneous delivery could well prove to be an advantage over more advanced intravenous anti-FcRn assets; however, Immunovant still needs to compete on safety and efficacy – and the real picture on these measures is much harder to draw from such a small trial, particularly relative to competitors. Still, phase II data triggered the $6.5bn takeout of Momenta this month and investors will be hoping that Immunovant – a single-asset company worth $2.8bn – goes the same way.
|Cross-trial comparison of anti-FcRn antibodies|
|IMVT-1401 (Immunovant) n=15||Efgartigimod (Argenx) n=128||Nipocalimab (J&J/Momenta) n=60|
|Placebo adjusted MG-ADL responder rate (> 2-point)*||40%||40%||37%|
|*Each study measured the endpoint at different time points, and used slightly different definitions of a responder. Source: Company presentations.|