US drug maker AbbVie and Germany’s Boehringer Ingelheim are collaborating to develop and commercialize BI 655066, a potential treatment for psoriasis. The drug is also being evaluated to treat Crohn’s disease, psoriatic arthritis and asthma.

BI 655066 selectively blocks IL-23, a key protein involved in skin inflammation which has been linked to an overactive immune system and is one of the main causes of the skin disease.

Boehringer said it was strongly committed to establishing immunology as a core area of expertise and building its pipeline and capabilities in this important therapeutic area.

The agreement follows reports earlier this month which said talks between the two companies about a partnership in oncology were at an advanced stage.

Michael Severino, AbbVie’s executive vice president and chief scientific officer, said BI 655066 had a good chance of being best-in-class. In the Phase 2 study, 69% of patients with moderate-to-severe plaque psoriasis maintained clear or almost clear skin nine months after taking the drug, compared with 30% of patients taking Johnson & Johnson’s Stelara (ustekinumab). Skin clearance was also faster and lasted longer.

The treatment would compete in a market crowded with other options, including AbbVie’s top product Humira. Other immunology therapies are being developed by Johnson & Johnson, Merck & Co, Novartis, Eli Lilly and AstraZeneca.

The companies will establish a joint steering committee for the development and initial commercialization of BI 655066. AbbVie will have sole responsibility for commercializing the drug while Boehringer will have the right to co-promote for asthma.

AbbVie also gains rights to BI 655064, an antagonistic anti-CD40 antibody, which Boehringer is testing in an early stage study against lupus. The CD40-40L pathway is thought to play a major role in immune disease such as lupus nephritis, Crohn’s and ulcerative colitis.

Boehringer will lead development of BI 655064 and AbbVie has an option to advance the program depending on the outcome of clinical trials.

Under the terms of the agreement, AbbVie will initially make an upfront payment of $595 million to Boehringer which will be eligible to receive additional undisclosed payments linked to development, regulatory and sales milestones.