US pharmaceutical giant Pfizer has obtained positive results in late-stage testing for a nasal spray designed to treat migraines, a study showed Thursday.

Pfizer said the study, which has been peer-reviewed and published in The Lancet Neurology journal, showed the company's drug zavegepant had proven to be "effective in the acute treatment" of migraines and had few apparent side effects.

The treatment for a condition generally tackled hitherto with orally taken medicines was double-blind tested on a sample of 1,405 people, with half taking a single spray dose and the remainder receiving a placebo.

The spray was found to reduce pain significantly when assessed two hours after the onset of a migraine, which as well as causing often severe headache can bring symptoms including nausea and sensitivity to light or noise.

The positive feedback thus far would appear to validate a strategic choice by Pfizer to acquire zavegepant last year for some $10 billion from developer Biohaven, along with other migraine treatments from the firm.

"This phase 3 trial aimed to compare the efficacy, tolerability, safety, and timecourse of response for zavegepant nasal spray with placebo in the acute treatment" of migraines, said The Lancet.

But it added that "additional trials are needed to establish the long-term safety and consistency of effect across attacks".

The treatment is already the subject of a number of requests for approval from the US health authority, the FDA. As yet there is no procedure under way for its use in Europe.

James Rusnak, Pfizer's senior vice president and chief development officer, said the drug "has the potential to be a significant new treatment option" for people with migraines, "particularly those who desire fast-acting relief or would benefit from an alternative delivery method".

© 2023 AFP