ALL-DAY RELIEF FROM ADHD: The U.S. Food and Drug Administration is now considering whether to approve the marketing of Vyvanse (lisdexamfetamine dimesylate, made by Shire) to adults with attention-deficit hyperactivity disorder (ADHD).
Shire filed for that application in June, following up on the FDA’s approval of Vyvanse last February as a treatment for ADHD in children.
Like many ADHD medications, Vyvanse acts as a stimulant. (Paradoxically, stimulants can help offset such hyperactivity problems, possibly by leveling out inconsistencies in how fast different parts of patients’ brains process information.) Vyvanse, however, is a “pro-drug” compound that does not exert its therapeutic effect until after the body has metabolized it. That delayed action can stretch out how long the drug works: in studies, a dose of Vyvanse was able to combat ADHD symptoms for a full day. (The delay may also make it less appealing for abuse than conventional amphetamine stimulants are.)
The review period for the adult application is 10 months; look for a decision in spring 2008.
Last June the FDA also issued an “approvable letter” to Shire for another of its pending anti-ADHD products, Intuniv (guanfacine), a once-a-day extended-release tablet. An approvable letter indicates that the FDA is prepared to approve a new drug application once certain specified conditions, such as a request for additional information, are met. According to the filed application, Intuniv, which is not a stimulant, acts specifically on the brain’s prefrontal cortex to improve executive functions, such as working memory, impulse control, tolerance of frustration and regulation of attention.
EASING FIBROMYALGIA: Sufferers of fibromyalgia, a painful and frustratingly mysterious affliction of the muscles and connective tissue, can finally hope for some relief. Lyrica (pregabalin, made by Pfizer) became the first FDA-approved drug treatment for fibromyalgia in June. Not all fibromyalgia patients have found that Lyrica reduced their discomfort, and common side effects have included dizziness and sleepiness. The drug had previously been approved for use in treating the nerve pain of shingles. Still more applications may yet emerge: Lyrica is also in advanced clinical trials as a treatment for epilepsy and for generalized anxiety disorder.
NEW HOPE AGAINST RESISTANT BREAST CANCER: Ixabepilone, a compound being investigated by Bristol-Myers Squibb, shows some encouraging effectiveness against metastatic breast cancers that are resistant to three other standard chemotherapy drugs (anthracycline, taxane and capecitabine). That was the finding of a phase II clinical trial published in the Journal of Clinical Oncology in August. Ixabepilone belongs to a new class of potential chemotherapy agents called epothilones that inhibit the growth of cancer cells. In June the FDA accepted the company’s New Drug application for ixabepilone, and, based on expectations, a decision should have been announced in October.
NEW HIV TREATMENT: For the first time in 10 years, the FDA has approved a member of a new class of oral HIV medication. Selzentry (maraviroc, made by Pfizer) prevents HIV from entering white blood cells. The FDA granted the approval in August on an accelerated basis, after only 24 weeks of data collection during a clinical trial. The drug, however, is so far meant for use only by patients infected with a particular strain of the virus—CCR5-tropic HIV-1—that is resistant to many other antiretroviral therapies.