A program that has “many separate moving parts,” according to Dr Tim Cunnif, VP of global regulatory affairs and quality assurance, is shaping up as Ovation Pharmaceuticals gets ready for final FDA approval of Sabril (vigabatrin) for two types of epilepsy: infantile syndrome (IS); and refractory (i.e., untreatable by other means) complex partial seizure (CPS) in adults. An FDA advisory panel approved the applications for both, unanimously, provided that the final application contains more detail on a patient registry and risk evaluation and mitigation strategy (REMS) for the next several years’ of the drug’s use in the U.S.
While the intermediate approval (FDA usually, but not always, follows the recommendations of its advisory committees) is looked on as good news by neurologists who have been able to do little for some epilepsy patients (the drug will be a first-of-its-kind for infants), the reasons for caution are well known: a side effect of the drug is that some patients suffer permanent loss of peripheral vision. The drug has been commercial in Europe and the side effect became known only after several years’ use.
CPS occurs in more than a third of all epilepsies, says Deerfield, IL-based Ovation, and 30-36% of CPS adult patients have not been helped by existing drugs. Additionally, an estimated 2,500 cases of IS are diagnosed annually, and as many as 20% of these infants die before the age of five.
Specialty distribution, patient registry
Cunnif says that the product launch will have several elements to address risk awareness and post-marketing follow-up. The advisory committee, he says, wants appropriate labeling to identify the risk, and a program for both patient and physician education. One element of the patient education being contemplated is a website where visitors can simulate the loss of peripheral vision to get a sense of what’s at stake. A speakers program will be set up for physician education, and some testing of physician awareness will be conducted in order to validate the registration of those physicians in the treatment program.
To address the risk of vision loss, registered patients will be required to have baseline and then follow-up tests by a neuroophthamologist (there is a type of test that can be performed on infants as well). If the vision loss begins to appear, the patient, caregivers and physician must decide whether to continue the therapy. “There is a problem with access to ophthalmology resources in rural areas,” says Cunnif, “which we’ll try to address as part of the product rollout.”
The REMS will generate data on the success of patient and physician education, how consistently follow-up tests are performed, and outcomes of the therapy based on patient demographics. Final choice has not yet been made with the specialty pharmacy, although Ovation has worked with Theracom (Rockville, MD), a subsidiary of CVS Caremark, on previous specialty distributions.
Full FDA approval could come as soon as March, says Cunnif, after Ovation provided revised plans for the REMS. PC