Repurposing an FDA-Approved Drug for Treating Age-Associated Lung Fibrosis

Application

New use of an FDA-approved therapeutic, diroximel fumarate (Vumerity), for treating Idiopathic Pulmonary Fibrosis.

Key Benefits

Novel use of an FDA-approved drug, diroximel fumarate - DRF (Vumerity), for treating age-dependent lung fibrosis.
Lung-targeted inhaled delivery of DRF is effective for boosting lung antioxidant responses and inhibiting lung fibrosis.
FDA-approval of DRF via oral administration for multiple sclerosis (MS) provides opportunities for expedited market availability for pulmonary fibrosis.

Market Summary

Idiopathic pulmonary fibrosis (IPF), the most common type of lung fibrosis, is a serious and deadly lung disease with no known cause and no known cure currently available. IPF is characterized by progressive scar tissue formation, causing irreversible damage to the lung, which can ultimately lead to respiratory failure. IPF has a median survival of less than 3 years, and patients typically present with established lung fibrosis at the time of diagnosis. IPF is widely regarded as a disease of aging. The incidence and prevalence of IPF increase with age; two-thirds of IPF patients are older than 60 years at the time of presentation, with a mean age of 66 years at the time of diagnosis. According to the American Lung Association, approximately 50,000 new cases are diagnosed each year. The US holds the largest IPF market with the highest number of diagnosed prevalent cases. Current FDA-approved therapies have been shown to slow the progression of lung decline, however, they do not reverse established fibrosis and they are not a cure. Further, these therapies do not improve the quality of life for patients, they are associated with significant side-effects, and there is only a modest survival benefit. There is a need to develop effective treatments which can promote the reversal of age-dependent established fibrosis. The high price of regulatory-approved drugs and the rising prevalence of IPF are the primary contributors to the market's growth.

Technical Summary

Despite the well-recognized role of oxidative stress in aging and fibrosis, the ability to precisely target key mediators is an unmet need. Researchers at Emory have discovered that Nrf2, a master regulator of antioxidant responses, is defectively “turned off” in age-dependent lung fibrosis, which contributes to the disease progression. Diroximel fumarate (DRF) is an FDA-approved orally delivered drug for MS, which is known to activate Nrf2 and enhance antioxidant responses. Emory researchers have demonstrated that DRF can inhibit the development of pro-fibrotic phenotypes and promotes the reversal of established pro-fibrotic phenotypes in IPF lung myofibroblasts (the key scar generating cell type). They developed an inhaled formulation of DRF, and using an aging animal model of lung fibrosis, they demonstrated that inhaled DRF demonstrates efficacy for inhibiting the progression of age-associated lung fibrosis. Currently, oral delivery is the standard for IPF therapies; the two FDA-approved IPF treatments are administered orally. However, oral administration has a high potential for off-target effects; a number of significant side-effects have been reported for the current IPF therapies. Inhaled respiratory therapies offer several major advantages over oral delivery, including direct delivery to the target organ, avoiding first-pass drug metabolism, potential to achieve higher local drug concentration and/or increased drug duration in the lungs, and fewer systemic off-target side effects. This inhaled DRF therapeutic approach is novel because 1) it targets a key age-associated pathological mechanism in pulmonary fibrosis, which may be more effective than current therapies alone, 2) lung-targeted delivery offers the potential for reduced side-effects, and 3) its FDA-approval for oral delivery in MS offers the potential for expedited market availability for inhaled delivery for a lung fibrosis indication.