Genmab (GMAB) and AbbVie (ABBV) said that adding their drug epcoritamab to a standard chemotherapy mix helped people with an aggressive form of blood cancer stay cancer-free longer than chemotherapy alone.

The combination cut the risk of the cancer getting worse or the patient dying by 51% compared with standard treatment alone, the companies said Monday in a statement. Results were from a large study in newly diagnosed patients with diffuse large B-cell lymphoma, the most common type of non-Hodgkin lymphoma.

The treatment paired epcoritamab with R-CHOP, a long-used chemotherapy regimen. The companies said the safety of the combination looked generally similar to what doctors already expect from each drug on its own.

Because the treatment is still experimental, Genmab and AbbVie plan to meet with regulators around the world to discuss next steps.

Genmab shares rose 11% in Monday trading, and AbbVie gained 1.3%.

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