Pfizer's (PFE 0.66%) nasal spray Zavzpret was given the green light by the Food and Drug Administration earlier this month to treat patients with acute migraine. The company expects that the treatment will be available in pharmacies beginning in July.

With this approval, the pharmaceutical company now has an acute migraine treatment in nasal spray form to complement the oral treatment in its portfolio, Nurtec ODT. What could Zavzpret contribute to Pfizer's top line? Let's examine the phase 3 clinical trial results and the acute migraine market to gauge its sales potential.

A great treatment option for acute migraine

Migraines tend to cause a pulsing or throbbing sensation on one side of the head. Along with this pain, patients can experience sensitivity to light, nausea, and vomiting during an episode. A migraine episode can last from a few hours to days.

Migraines are split into two classifications: Chronic migraines persist at least 15 days per month for at least three months, whereas episodic (acute) migraines can occur less than 15 days per month. Most migraine patients -- 95% to 97% -- fit into the acute category.

Treatment of acute migraine is important for a couple of reasons. First, it can improve quality of life with less interference from the condition. Second, the risk of progression to chronic migraine in the following year in maximally treated patients is just 2.5%, versus 8.1% in patients with very poor or no treatment.

This is where emerging medicines such as Zavzpret could be instrumental in helping acute migraine patients. Pfizer enrolled patients with acute migraine into a randomized clinical trial to receive either a 10 milligram (mg) dose of Zavzpret or a placebo.

The medicine fared much better than placebo at helping patients to achieve the co-primary endpoint of pain freedom. Just as it sounds, this means a reduction in headache severity from the pre-treatment baseline to no pain after treatment. Patients in the treatment group achieved pain freedom at a rate of 24% at two hours post-dose, which was far better than the 15% rate observed in the placebo group.

And patients in the treatment group reported a higher rate of freedom from their most bothersome symptom (MBS) than in the placebo group. MBS was either sensitivity to sound, sensitivity to light, or nausea.

The treatment group achieved a 40% freedom from MBS at two hours post-dose versus just 31% in the placebo group. And because Zavzpret is a nasal spray, it began working in as little as 15 minutes, with relief lasting up to 48 hours after a 10 mg dose.

A patient attends a doctor appointment.

Image source: Getty Images.

Incremental sales potential

So Zavzpret is a highly effective treatment. What could this mean for Pfizer?

It's estimated that the global acute-migraine drug market will grow from $4.3 billion in 2021 to $9.3 billion by 2030. Zavzpret has two advantages that could help it seize market share in a crowded treatment market. First is its appeal to patients who need rapid pain relief or can't take oral medicines as a result of nausea or vomiting. Second, Pfizer has significant influence among the global healthcare community, which should help it to gain wide acceptance of this treatment.

This is why I believe the company could achieve an 8% global market share with Zavzpret. That equates to over $700 million in annual revenue. Compared to the $69.1 billion in sales that analysts expect from Pfizer in 2023, this alone is a 1.1% bump in the top line.

And as you would expect for a mega-cap pharmaceutical company, it also has an excellent pipeline outside of Zavzpret, with 100-plus projects currently in clinical development. 

A solid pick for value investors

Down 24% in the last year, shares of Pfizer have been hammered as of late. This poor performance appears to be an overreaction by the market regarding the anticipated plunge in the company's COVID-19 product revenue this year and beyond. Pfizer's in-house pipeline coupled with acquisitions should help the company to return to growth sooner rather than later.

Yet the stock's forward price-to-earnings ratio of 10.6 is well below the drug manufacturing industry's average of 13. The current $40 price represents an opportunity for value investors to pick up shares of Pfizer before the market warms up to the stock.