According to a story from Pharmaceutical Technology, the drug developer FibroGen’s phase 3 clinical trial testing pamrevlumab as a treatment for idiopathic pulmonary fibrosis could be in trouble. While the trial has yet to begin recruitment, certain aspects of the trial design may leave it with too few participants. The issue was first pointed out by a pair of idiopathic pulmonary fibrosis experts at the recent American Thoracic Society meeting.
About Idiopathic Pulmonary Fibrosis (IPF)
Idiopathic pulmonary fibrosis is a deadly, chronic, progressive lung disease which is characterized by lung tissue scarring, leading to a decline in lung function over time. The cause of idiopathic pulmonary fibrosis is unknown. With that being said, there are a few risk factors that have been identified, such as smoking cigarettes, exposure to various dusts (metal, wood, stone, and coal dust), occupations related to farming, family history, and potentially certain viral infections. Symptoms include shortness of breath, a dry cough, a distinctive crackling sound detected with a stethoscope, oxygen deficiency in the blood, and clubbed digits. There are few treatment options that can have a significant impact on the progression of idiopathic pulmonary fibrosis. Treatment may include certain medications, pulmonary rehabilitation, oxygen therapy, and lung transplant. Early intervention can make a major difference in outcomes; five year survival rate is between 20 and 40 percent. To learn more about idiopathic pulmonary fibrosis, click here.
A Flawed Design?
The trial design was first made public on May 17th. The challenge with this trial is that it does not permit patients to be using a background treatment while they are participating. Many clinical trials, especially for serious diseases, allow patients to continue their regular medication, especially if the patient has a chance of getting a placebo during the study. At this stage there are some medications that can help slow disease progression, so asking patients to quit a treatment that is working could literally shorten their lifespan.
The trial also has an ambitious recruitment goal of 565 patients total. One of the disease specialists suggested that the trial would be best suited to patients that could not tolerate or did not respond to current standard treatments. The trial is meant to screen for patients that are not being treated with either nintedanib or pirfenidone (two of the most common drugs), but there are few patients that are not using one or the other.
This is all complicated by another 750 participant trial idiopathic pulmonary fibrosis trial that is currently being conducted by Galapagos, which does allow for combination with standard of care drugs. One of the specialists said that a revised combination style design would be the best option for FibroGen’s trial.