A late-stage trial of Pfizer's gene therapy for a rare genetic bleeding disorder has been successful.

• A large late-stage trial demonstrated the success of Pfizer's experimental gene therapy for a rare genetic blood-clotting disorder, increasing the likelihood of a potential approval.
• The company's second gene therapy to enter the U.S. market after Beqvez, which was cleared in April for hemophilia B, could be used to treat hemophilia A.
• Several drugmakers, including Pfizer, are investing in gene and cell therapies, which are one-time, high-cost treatments that target a patient's genetic source or cell to cure or significantly alter the course of a disease.

On Wednesday, it was announced that the experimental gene therapy for a rare genetic blood-clotting disorder had succeeded in a large late-stage trial, opening up the possibility of approval.

Hemophilia A treatment could be the second gene therapy to enter the U.S. market after Beqvez, which was approved in April for a rare type of bleeding disorder known as hemophilia B.

Pfizer's stock was flat on Wednesday, while the shares of the therapy's co-developer rose more than 60% following the data release.

Several drugmakers, including Pfizer, are investing in gene and cell therapies, which are one-time, costly treatments that target a patient's genetic source or cell to cure or significantly alter the course of a disease. Some industry health experts predict that these therapies will replace traditional lifelong treatments that patients take to manage chronic conditions.

The disease hemophilia A is a lifelong condition resulting from a deficiency of the blood clotting protein factor VIII. This protein is necessary for blood to clot properly, and without it, the risk of spontaneous bleeding and severe bleeding after surgery increases. Hemophilia A affects approximately 25 males out of every 100,000 births worldwide, according to Pfizer, who released this information.

The drug developed by Pfizer significantly reduced the number of annual bleeding episodes in patients with moderately severe to severe hemophilia A after 15 months, according to the company. Additionally, the drug outperformed the current standard treatment for the disease, which involves routine infusions that replace the Factor VIII protein.

The emotional and physical impact of frequent IV infusions or injections for people with hemophilia A cannot be overlooked, according to Dr. Andrew Leavitt, the lead investigator of the trial.

Pfizer stated that the study is still ongoing and they will provide more information at forthcoming medical conferences.

If approved, Pfizer's therapy will compete with BioMarin's one-time treatment Roctavian. The slow rollout of BioMarin's therapy since it won approval in the U.S. last year has raised questions about how many patients would take Pfizer's drug if it enters the market.

BioMarin is reportedly considering divesting its hemophilia A therapy, which costs $2.9 million.