Pressure mounts on US FDA to address alleged persistent sexual dysfunction with Merck's hair loss drug
This article was originally published in Scrip
As physicians call for the US FDA to address reports of persistent sexual dysfunction with Merck & Co's male-pattern hair loss drug Propecia (finasteride), the US Judicial Panel on Multidistrict Litigation in San Diego, California, has scheduled a 29 March hearing session that will determine if a number of individual law suits filed against the company should be "centralised" in one legal action.
Regulators in Europe were quicker to address the issue and Sweden's Medical Products Agency started investigating adverse event reports regarding sexual dysfunction as far back as 2006. The European Summary of Product Characteristics was updated to state: "In addition, the following have been reported in post-marketing use: persistence of erectile dysfunction after discontinuation of treatment with Propecia; male breast cancer."
In the US, the patient leaflet first states: "A small number of men experienced certain sexual side effects. These men reported one or more of the following: less desire for sex; difficulty in achieving an erection; and, a decrease in the amount of semen. Each of these side effects occurred in less than 2% of men. These side effects went away in men who stopped taking Propecia. They also disappeared in most men who continued taking Propecia."
Only further down the document, does it note that "in general use, difficulty in achieving an erection that continued after stopping the medication has been reported".
However, US doctors say this is not enough. Michael Irwig, assistant professor of medicine at the George Washington University School of Medicine, told Scrip: "The current statement is not sufficient. My study found not only persistent erectile dysfunction, but also persistent low libido and inability to have orgasm."
Dr Irwig, who last year published his findings on the types and duration of persistent sexual side effects in otherwise healthy men taking finasteride for male pattern hair loss in the Journal of Sexual Medicine, added: "I would like to see [the labelling] state that some men have developed persistent sexual problems that have lasted 5-10 years after stopping finasteride."
He added: "I would the FDA to thoroughly conduct a safety review using the hundreds of adverse medication effect reports that have been submitted by individuals over the past 10 years. It is extremely distressing for a young man with previously normal sexual function to develop persistent sexual side effects. I have spoken to over 100 such men about their individual stories."
The FDA told Scrip, "We've said before publicly that the FDA is looking at the persistence of severe male sexual dysfunction after discontinuation of Propecia's use. This ongoing review was prompted by routine drug safety surveillance."
It added that routine safety surveillance includes a number of things, such as regular monitoring of adverse event (MedWatch) reports (AERS), reviewing scientific literature and looking at data from post-market clinical trials.
"For our AERS website, FDA staff in the Center for Drug Evaluation and Research (CDER) and Center for Biologics Evaluation and Research (CBER) regularly examine the AERS database as part of routine safety monitoring. Potential signals of serious risks are normally based upon groups of AERS reports, although a single AERS report could lead to further evaluation of a potential safety issue," the FDA added.
Meanwhile, the US Judicial Panel on Multidistrict Litigation in San Diego, California, is to decide on 29 March on a motion put forward by plaintiff, Christopher Masefield, for the centralisation of nine actions in the US District Court for the Eastern District of New York. These include suits initiated in various districts including those in Colorado, Florida, Illinois, New Jersey, New York, Ohio and Washington.
Of note, Merck's official website for Propecia, has been shut down, stating: "Thank you for visiting propecia.com. This Web site is not currently available."
Merck said to Scrip, "The website is being refreshed and is expected to be available again soon. Until then, the website includes links to the prescribing information and patient product information. Also, we encourage patients to speak with their healthcare provider if they have any questions about their health."
An SEC filing on 28 February from Merck states: "As previously disclosed, Merck is a defendant in product liability lawsuits in the US involving Propecia and/or Proscar. As of December 31, 2011, approximately 70 lawsuits involving a total of approximately 170 plaintiffs (in a few instances spouses are joined in the suits) who allege that they have experienced persistent sexual side effects following cessation of treatment with Propecia and/or Proscar have been filed against Merck. The lawsuits, which are in their early stages, are pending in federal courts in New Jersey, Washington, Washington DC, Florida, Illinois, Colorado, Missouri and Ohio, and in state court in New Jersey. Certain of the federal plaintiffs have petitioned the JPML to have the federal lawsuits consolidated for pre-trial purposes, and certain of the New Jersey state court plaintiffs have petitioned for consolidation of the New Jersey state court cases. Resolution of these motions remains pending. The Company intends to defend against these lawsuits."
The concerns over continued sexual dysfunction with Propecia comes after the FDA warned in June last year that 5-alpha reductase inhibitors (5-ARI), such as Propecia, as well as Merck's Proscar (finasteride) and GlaxoSmithKline's Avodart (dutasteride) and Jalyn (dutasteride and tamsulosin), increased the risk of high-grade prostate cancer (scripintelligence.com, 14 June 2011).