According to a press release from the San Francisco-based FibroGen, Inc., the first patient has been dosed in the Company’s phase 3 clinical study of the experimental drug pamrevlumab for the treatment of idiopathic pulmonary fibrosis.
About Idiopathic Pulmonary Fibrosis
Idiopathic pulmonary fibrosis (IPF) is a condition characterized by progressive scarring of the lung tissue with no known cause. Over time, it may become difficult for those affected to take deep breaths as their lungs struggle to take in adequate amounts of oxygen.
Like many conditions with uncertain origins, scientists suspect that a combination of genetic and environmental factors are responsible in varying degrees for triggering IPF. As many as one in five people with IPF are believed to have a relative with a similar lung disease, suggesting that genetic factors may be at least partially in play. However, even more condemning is the prevalence of IPF among smokers — some estimates suggest that as much as 75% of those affected by IPF smoke or formerly smoked cigarettes.
About Pamrevlumab and the Phase 3 Clinical Trial
The first patient in FibroGen’s phase 3 trial has been dosed, according to the Company. FibroGen plans on enrolling around 565 participants in the study that will monitor patient response to pamrevlumab (or placebo) over a 52-week period.
The double-blind, randomized trial was informed by positive results yielded in pamrevlumab’s earlier phase 2 trials. Participants will be evaluated on changes to their forced vital capacity over the treatment period. Forced vital capacity is a figure that represents the amount of air expelled during a forced exhale — it can be thought of as a generally simple way of assessing lung strength and functionality.
Pamrevlumab is an antibody that works by inhibiting the activity of connective tissue growth factor (CTGF), a regulatory protein with complex biology. CTGF is thought to play a role in numerous important signalling pathways that can cause fibrosis in certain individuals. It also seems to play a role in the formation of certain kinds tumors, which can involve several of the same pathways.
Pamrevlumab has already received Orphan Drug designation from the FDA for idiopathic pulmonary fibrosis, locally advanced unresectable pancreatic cancer, and Duchenne muscular dystrophy. Orphan Drug designation comes with a slew of benefits when the recipient drug finally comes to market, and it seems like pamrevlumab could gain approval for select conditions in the near future. However, that may depend on the outcome of phase 3 trials like the one underway right now.
Idiopathic pulmonary fibrosis can be an especially intimidating condition because it has no known single cause. What unique difficulties might there be in developing treatments for conditions with poorly understood origins? Share your thoughts with Patient Worthy!