Immunovant's muscle drug meets main goal, shares gain on new drug promise

By Christy Santhosh and Kamal Choudhury

March 19 (Reuters) - Immunovant IMVT.O said on Wednesday its experimental treatment for a type of chronic muscle weakness improved patients' symptoms and that it aimed to use the data to accelerate the development of a newer drug.

The company was testing the drug, batolimab, for Myasthenia gravis (MG), a disease affecting the muscles that help in eye movement, facial expressions, chewing, swallowing and speaking.

Immunovant's shares were last up nearly 3%, reversing from a 7% slump in early trading, after the company said it would use the late-stage data to design future studies, which may include a head-to-head trial, for its lead drug IMVT-1407.

In the late-stage study, batolimab helped reduce levels of the immunoglobulin G (IgG) antibody, which plays a role in the weakening of muscles.

While this was not the study's main goal, at least two analysts said the data bodes well for Immunovant's other drug, IMVT-1402, which could be even more effective.

"These data reinforce the thesis that deeper IgG lowering matters to drive greater clinical efficacy in MG," said Piper Sandler analyst Yasmeen Rahimi.

Immunovant currently does not plan to seek marketing approval for batolimab.

Batolimab showed a 74% and 64% reduction on average in IgG levels in patients who took the higher and lower doses, respectively.

Patients on the higher dose showed a 5.6 point improvement on a patient-reported scale that measures the ability to perform daily activities, compared with a 3.6-point improvement for those on a placebo.

UBS analyst Ashwani Verma said the effectiveness of batolimab, after adjusted for placebo, is below the efficacy of Argenx SE's ARGX.BR Vyvgart Hytrulo, which is already approved to treat the condition.