Wow – the approvable letters are flying off the shelves. If you are not familiar with approvable letters, see my posting "What Does Approvable Mean?" Or you may wish to listen to my podcast on the subject of approvable letters.
First – Pfizer announced yesterday that its investigative compound Maraviroc – a treatment for HIV – has been deemed approvable by the FDA. Apparently the FDA had some unanswered questions, but has not, according to reports, asked for new clinical trials. According to the Pfizer release – We continue our discussions with the FDA to address outstanding questions and finalize the product labeling as soon as possible. Pfizer is committed to making maraviroc available to the thousands of patients with HIV whose virus has become resistant to one or more currently available treatment options.
Second, in the notoriously difficult ADHD category, Shire Pharmaceuticals announced today that it received an approvable letter for INTUNIV (guanfacine) extended release tablets (previously referred to as SPD503), a nonstimulant selective alpha-2A-receptor agonist. The company states in its release that the approvable letter was not a surprise. “The FDA’s approvable letter for INTUNIV is positive news, and Shire will be working closely with the agency to address its questions,” said Matthew Emmens, CEO of Shire. Shire received an approvable letter in October of 2006 in this same category, and again in May 2007.
Does this spate of letters indicate something? Some think FDA is issuing approvable letters in greater numbers to put off approvals, but I don’t see any evidence of that myself.