FDA Approves Linaclotide as a Generic Drug to Treat IBS-C

The US Food and Drug Administration (FDA) has approved the first generic drug to treat irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation.

The FDA announced they approved linaclotide 145 mcg capsules, as well as 290 mcg capsules from Mylan Pharmaceuticals as a generic to treat this patient population.

“Generic drug competition can help reduce prices, improve access, and benefit public health,” the FDA’s Media Affairs account tweeted on February 10. “All generic drugs are held to high approval standards, ensuring that they are as safe, effective, and high-quality as the brand-name drug.”

Linaclotide has been marketed for this indication as LINZESS by Ironwood Pharmaceuticals to treat abdominal symptoms in patients with IBS-C. The guanylate cyclase-C (GC-C) agonist locally binds to the GC-C receptor within the intestinal epithelium.

In 2020, researchers found that rates of drug discontinuation is high in IBS patients, evaluating the reasons and timing of discontinuation of different FDA approved pharmacotherapies for irritable bowel syndrome and chronic idiopathic constipation.

The main reason for discontinuation over the first year of therapy is a loss of prescription drug coverage. The investigators believe the study could help better inform the patient-centered discussion centered around the comparative outcomes of discontinuations.

For the first year of therapy, more than half of the discontinuations were because of intolerance that occurred in the first 3 months for both drugs. Linaclotide users were more likely to discontinue because of intolerance than lubiprostone users (HR, 1.6; 95% CI, 1.2-2.3), but less likely to discontinue due to insufficient efficacy of therapy (HR, 0.5; 95% CI, 0.4-0.8).

Irritable bowel syndrome diagnosis also increased the hazard of discontinuation of lubiprostone relative to linaclotide (HR, 1.4; 95% CI, 1.1-1.6).