Bullous Pemphigoid (BP) is an auto-immune blistering disease of the skin which affects 30,000 Americans and an estimated 90,000 people worldwide (1/3 with moderate to severe disease). Most of the patients are over 60 years old, require several visits before being diagnosed, and have limited therapeutic alternatives. The mainstay of treatment is oral prednisone at high doses for several months with risk of relapse when steroids are tapered down or discontinued. Europeans also use topical steroids on large areas of the body. The chronic use of steroids is responsible for a worsening of multiple conditions, including osteoporosis, bone fractures, severe infections, and cardio-metabolic diseases. As a result hospitalization is frequent and mortality is double that of people the same age without the disease.
Most patients with BP have high levels of eosinophils, white blood cells that secrete pro-inflammatory substances in the blood stream and locally in the skin. Eosinophil migration and activation is regulated by eotaxin-1, a protein targeted by Immune Pharmaceuticals’ first in class monoclonal antibody, bertilimumab. This is the reason why the patient advocacy group, the International Pemphigus and Pemphigoid Foundation (IPPF), approached Immune and connected the company with leading physicians treating BP.
Immune formed a Scientific Advisory Board and designed a phase II open label trial with the following goals: assessing the safety of multiple doses of intravenous (IV) bertilimumab administered every two weeks for one month, evaluating the clinical response to bertilimumab on a background of 30mg of oral prednisone tapered down as the patient shows symptom improvement, and lastly evaluating the number of patients successfully tapered down to 10mg of oral prednisone or less without short term disease relapse. The Bullous Pemphigoid Disease Activity Index (BPDAI) is a comprehensive score that has been validated by leading dermatologists. A score between 50-70 is high and reflects moderate to severe disease. A score below 10 suggests the patient is achieving a meaningful response with no or very limited symptoms.
After a delayed initiation and an assessment of the first few patients to complete treatment, patient recruitment is accelerating in Israel (2 centers) and now in the United Stated (6 centers). This is encouraging as a meaningful clinical response in a majority of the approximately 10 planned patients would support further development of bertilimumab in BP with additional trials looking not only at induction treatment, but also at maintenance and ability to control the disease with bertilimumab on a background of a minimal dose of prednisone, as in many other auto-immune and inflammatory diseases.
Such an outcome would be game-changing for BP patients and would create an opportunity for Immune Pharma estimated at a value globally of $500M to over $1 billion. This would also be the first proof of clinical relevance for bertilimumab and further support development in other dermatological indications such as atopic dermatitis which affects over 1 million adult Americans. Development in Ulcerative Colitis (UC) and Crohn’s Disease is ongoing with a phase II double blind placebo controlled UC trial which is also accelerating patient recruitment toward completion. Other indications, including NASH, a severe inflammation of the liver, are supported by the over 1500 publications on eotaxin-1, and will be considered for further development in 2017 and beyond.
Bertilimumab, which was discovered by Cambridge Antibody Technologies, the originator of Abbvie’s blockbuster Humira, is finally approaching the limelight and creating hope for patients with severe inflammatory diseases.