What happened

Shares of Kezar Life Sciences (KZR -0.30%) were soaring 36.1% as of 11:03 a.m. EST on Tuesday. The big gain came after the company announced interim results on Monday from a phase 2 study evaluating KZR-616 in treating autoimmune disease lupus nephritis.

So what

With the huge move for the biotech stock today, it's not surprising that Kezar's results were really good. The company reported that four out of five patients receiving KZR-616 in the phase 2 study achieved either a partial or complete renal response.

Scientists looking through microscopes.

Image source: Getty Images.

Kezar chief medical officer Noreen Henig said that researchers observed "meaningful reductions" in proteinuria (increased levels of protein in the urine) at six months plus "encouraging data" after three months. Importantly, KZR-616 appeared to modulate the immune system in a helpful way rather than just suppress immune responses. Kezar believes this could give the drug advantages over current therapies.

The company said that KZR-616 demonstrated a favorable safety and tolerability profile. There weren't any new safety issues observed in the phase 2 study. Adverse events that were observed were generally mild to moderate. No participants dropped out of the study due to drug-related adverse events, although there was one temporary interruption due to a migraine.

Now what

Kezar noted that the data reported was only preliminary. The company said that confirmation will be required in additional patients. It plans to announce top-line data from the phase 2 study in the second quarter of 2022.