In March 2017, the FDA issued a warning against Allergan’s Viberzi (eluxadoline), which was approved in May 2015 in the US for the treatment of diarrhoea-predominant irritable bowel syndrome (IBS-D).
As per the FDA warning, the drug should not be used in IBS-D patients who do not have a gall bladder. From May 2015 through February 2017, the FDA received 120 reports of serious cases of pancreatitis or death. A total of 68 of these patients reported their gallbladder status to the regulatory agency, out of which 56 patients did not have a gallbladder but received the recommended doses of Viberzi.
A total of 76 patients were hospitalized, and two patients who did not have a gallbladder died. Sphincter of oddi spasm (n=6) and abdomen pain (n=16) were reported for some patients who had serious pancreatitis or death.
Viberzi has been available in the US market since December 2015. The drug was approved for the treatment of IBS-D in the EU in September 2016 (trade name Truberzi). Allergan intends to begin commercializing the drug in the EU in 2017, following successful negotiations with the relevant national payers and reimbursement groups.
Viberzi was originally developed by Furiex Pharmaceuticals, and became a part of Allergan’s product portfolio through a series of acquisitions. The drug is a first-in-class mixed opioid µ-receptor agonist, δ-receptor antagonist, and ?-receptor agonist that acts locally to reduce visceral hypersensitivity without causing complete disruption of intestinal motility. Viberzi’s peripheral δ-opioid receptor antagonism affects central analgesia and enhances μ-opioid receptor-mediated peripheral analgesia, and the same mechanism is believed to be responsible for reduction of μ-opioid receptor-mediated constipation.
As a consequence of pancreatitis events in Viberzi-treated patients, the FDA issued a warning that patients without a gallbladder should stop taking Viberzi and seek emergency medical care if they develop new or worsening symptoms in the stomach area.
For healthcare providers, the FDA issued an additional warning that Viberzi should not be prescribed to IBS-D patients with no gallbladder, and alternative options should be considered in such patients. In patients with no gallbladder and those who do not consume alcohol, symptoms of pancreatitis were observed after one or two doses of the recommended 75mg of Viberzi.
GlobalData anticipates that this warning limiting Viberzi’s use will pose as a hindrance to Allergan’s ambition of fetching greater revenue from the drug in the IBS market. While this could mean bad news for Allergan, it could turn into a benefit for Salix’s Xifaxan (rifaximin) in the US. Xifaxan is a gut-selective, broad-spectrum antibiotic available in the US for the treatment of IBS-D. Xifaxan was approved by the FDA on the same day as Viberzi, and both drugs have since been in a head-to-head rivalry over the large but under-served IBS-D market.