GlaxoSmithKline and Pozen Inc have announced that the US Food and Drug Administration (FDA) has issued a second approvable letter for Trexima (sumatriptan/naproxen sodium). An approvable letter is an official notification from the FDA that contains conditions that must be satisfied prior to obtaining final US marketing approval.
In January 2007, Pozen and GSK responded to the FDA's first approvable letter, submitting additional safety data from clinical trials, data from GSK's database, and additional in vitro pre clinical data. In the second approvable letter, no additional information regarding the cardiovascular safety of Trexima was requested. The companies agreed to conduct a prospective study after approval to evaluate the effects on blood pressure during chronic, intermittent treatment.
The FDA has requested that Pozen further address the Agency's concern, prior to approval; about the potential implications from one preclinical in vitro chromosomal aberration study (one of four standard genotoxicity assays) in which genotoxicity was seen for the combination of naproxen sodium and sumatriptan, but not with either component alone. None of the other three standard genotoxicity studies (Ames test, mouse lymphoma TK assay, in vivo mouse micronucleus assay) demonstrated any genotoxicity for the combination of naproxen sodium and sumatriptan.
The companies intend to request a meeting with the FDA as quickly as possible to discuss the necessary steps to address the Agency's concerns.
Trexima was the proposed brand name for the product candidate combining sumatriptan 85 mg, as the succinate salt, formulated with RT Technology and naproxen sodium 500 mg in a single tablet. Several new names are under consideration at FDA, but pending a final decision on a new name the product will still be referred to as Trexima.
The FDA had previously determined that Trexima is effective as an acute treatment for migraine headaches. Pozen and GSK will continue to work with the FDA on revisions to the proposed package insert and the proposed trade name.
Imitrexis a prescription medication indicated for the acute treatment of migraine in adults. Imitrex should only be used when a clear diagnosis of migraine has been established. Patients should not take Imitrex if they have certain types of heart disease, history of stroke or TIAs, peripheral vascular disease, Raynaud syndrome, or blood pressure that is uncontrolled. Patients with risk factors for heart disease, such as high blood pressure, high cholesterol, diabetes or are a smoker, should be evaluated by a doctor before taking Imitrex. Very rarely, certain people, even some without heart disease, have had serious heart related problems. Patients who are pregnant, nursing, or taking medications should talk to their doctor.