What happened

Shares of Momenta Pharmaceuticals (NASDAQ:MNTA) were up by about 15% at 2:04 p.m. EDT Monday after the biotech released positive results from its phase 2 clinical trial of nipocalimab as a treatment for generalized myasthenia gravis.

So what

Generalized myasthenia gravis is a chronic autoimmune neuromuscular disease that causes the immune system to creates antibodies that block muscle receptors responsible for getting signals from nerve cells. Nipocalimab is designed to block those deleterious antibodies.

The clinical trial tested four different dosing regimens and found that 52% of patients treated with nipocalimab improved at least 2 points on the Myasthenia Gravis Activities of Daily Living scale for at least four consecutive weeks, compared to just 15% of patients taking a placebo. As expected, patients with larger reductions in the antibodies that cause the disease had better improvements on the scale.

Doctor talking to a patient

Image source: Getty Images.

Now what

The study is still ongoing with patients being treated for 16 weeks. Final data is expected in the fourth quarter, but it seems likely that it'll show the drug is working. Momenta is already planning to start a phase 3 clinical trial next year.

Beyond generalized myasthenia gravis, Momenta is testing nipocalimab against two other autoimmune diseases caused by deleterious antibodies: warm autoimmune hemolytic anemia and hemolytic disease of the fetus and newborn. Those programs are somewhat de-risked thanks to the positive results so far for the treatment in generalized myasthenia gravis, although Momenta will still need to show that reducing the harmful antibodies in question can reverse the symptoms of those diseases.