General Information

Tosymra is a nasal spray formulation of sumatriptan, a selective 5-HT1B/1D receptor agonist.

Tosymra is specifically indicated for the acute treatment of migraine with or without aura in adults.

Tosymra is supplied as a spray for intranasal administration. The recommended dose is 10 mg given as a single spray in one nostril. The maximum cumulative dose that may be given in a 24-hour period is 30 mg, with doses separated by at least one hour. Tosymra may also be given at least one hour following a dose of another sumatriptan product.

Clinical Results

FDA Approval

The efficacy of Tosymra was based on the relative bioavailability of Tosymra nasal spray compared to sumatriptan subcutaneous injection (4 mg) in healthy adults. Following nasal administration of 10 mg of Tosymra in 73 healthy adults, the relative bioavailability of Tosymra was approximately 87% of that obtained following 4 mg subcutaneous injection of sumatriptan. The relative bioavailability of Tosymra was approximately 58% of that obtained following 6 mg subcutaneous injection of sumatriptan.

Tosymra was evaluated in a phase II multicenter, double-blind study conducted in 107 subjects with episodic migraine. The subjects were randomized to receive either Tosymra or placebo to treat a migraine attack with a moderate or severe pain level. The primary endpoint was the proportion of subjects with migraine pain freedom at 2 hours postdose (2hPF). Data showed there was a significantly higher proportion of subjects who experienced 2hPF with Tosymra compared with placebo: 43.8% (n=48) versus 22.5% (n=40). Tosymra was also significantly better than placebo at alleviating the patients' most bothersome symptom (MBS), including nausea, photophobia, and phonophobia (70.7% versus 39.5% MBS free at 2 hours postdose).

Mechanism of Action

Tosymra (sumatriptan) is a sulfonamide triptan with vasoconstrictor activity. Sumatriptan selectively binds to and activates serotonin 5-HT1D receptors in the central nervous system (CNS), thereby constricting cerebral blood vessels. This may lead to a relief in pain from vascular headaches. Sumatriptan may also relieve vascular headaches by decreasing the release of vasoactive neuropeptides from perivascular trigeminal axons in the dura mater during a migraine, by reducing extravasation of plasma proteins, and by decreasing the release of other mediators of inflammation from the trigeminal nerve.