GSK’s Investigational Asthma mAb May Beat Competitors to Market

During a second quarter GlaxoSmithKline (GSK) earnings call, GSK’s CEO Andrew Witty said that although the company’s monoclonal antibody (mAb) Nucala (mepolizumab) has some overlap with Xolair (omalizumab), an existing mAb for the treatment of refractory asthma, “mepolizumab has potential utility in a much broader, much larger population than Xolair.” But because mepolizumab may potentially launch in late 2015, it will not be assigned a reimbursement J-code until January 2016, meaning that its revenue numbers may not be conclusive until early 2016. Despite the gap in the assignment of a J-code, Witty said he thinks the GSK mAb will be at least six or eight months ahead of potential market competitors, and “certainly years ahead of AZ [AstraZeneca] and others.”

Witty refers to the various targeted biologic therapies that are currently in late-stage development for asthma, including Teva’s Cinquil (reslizumab), Roche’s lebrikizumab, AstraZeneca’s tralokinumab, and Sanofi and Regeneron's dupilumab. Most of the large-molecule drugs in the asthma pipeline are interleukin inhibitors targeting inflammatory pathways and are indicated for patients who have a reduced sensitivity to corticosteroids.

Many of the current manufacturers of asthma control medications are turning away from small-molecule solutions and looking to biologics for the management of breathing-related ailments. Because the asthma market is fairly saturated, many payers and pharmacy benefit managers have started excluding certain higher-priced small-molecule asthma therapies-most of which are corticosteroids-from its formularies. Witty said that pricing pressure “continues to impact Advair/Seretide in the quarter, as contracting changes continue in the US and generic competition increases in Europe” and internationally. GSK's global sales were down 7% pro forma, primarily driven by Advair, which was associated with sales decreases of 17%, and an expected sales decline of approximately 20% for the full year, Witty said during the call. He added, “We expect Advair/Seretide to continue to decline at similar rates in the second half as we progress the transition of our respiratory portfolio to newer products around the world."

Mepolizumab is an anti-interleukin (IL)-5 mAb delivered as a 100-mg fixed dose via a subcutaneous injection every four weeks. In Phase III clinical trials, the drug demonstrated a statistically significant reduction in asthma exacerbations in patients with severe eosinophilic asthma. Recently, an FDA advisory panel unanimously agreed that the drug showed a clinically meaningful benefit. The medication has an FDA action date of November 4, 2015 and has been filed for approval in Japan.

GSK’s investigational mAb is also in clinical trials for the treatment of atopic dermatitis, hypereosinophilic syndrome, eosinophilic esophagitis, nasal polyposis, eosinophilic granulomatosis with polyangiitis (i.e., Churg Strauss syndrome), and chronic obstructive pulmonary disease (COPD).

Genentech/Sanofi’s anti-IgE mAb Xolair, which was approved by FDA in 2003, is meant for patients with moderate to severe persistent asthma whose symptoms are not well controlled by inhaled corticosteroids, and for patients with chronic idiopathic urticaria, which is commonly known as chronic hives.