Sanofi's versatile Qfitlia scores FDA nod to enter crowded hemophilia market

 Over the last three years, the FDA has approved six new hemophilia drugs, including three gene therapies.

Into this crowded treatment landscape comes another new medicine as the FDA has signed off on Sanofi’s Qfitlia (fitusiran), which sets itself apart as the only treatment for all types of hemophilia.

Not only is Qfitlia for those with hemophilia A and B, but unlike most treatments for the disorder, it also can be used by patients regardless of their inhibitor status.

With hemophilia patients, “inhibitors” are antibodies that counter the effectiveness of clotting factor replacement therapies. Some hemophilia A patients may develop factor VIII inhibitors, while factor IX inhibitors may arise in some hemophilia B patients.

“It’s a really exciting time for people living with hemophilia as it relates to the emergence of new therapies,” Craig Benson, M.D., Sanofi’s hemophilia program leader, said in an interview with Fierce Pharma. “We’re obviously excited about fitusiran because it’s the first therapy in the United States that can be used by all patients.”

Qfitlia can be administered under the skin starting once every two months, and its dose and frequency can be adjusted using a companion diagnostic test.

“Today’s approval of Qfitlia is significant for patients with hemophilia because it can be administered less frequently than other existing options,” said Tanya Wroblewski, M.D., deputy director of the FDA’s division of non-malignant hematology, said in a statement Friday.

As a small interfering RNA (siRNA) drug, Qfitlia mimics a natural cellular process that regulates gene expression. By suppressing antithrombin (AT), a protein that inhibits blood clotting, Qfitlia promotes thrombin generation, which helps prevent bleeding episodes that plague those with hemophilia.

“It’s a different pathway in the coagulation system to rebalance hemostasis,” Benson said. “Our coagulation system is a delicate balance, for all of us, between allowing our blood to stay slippery and smooth and flow, versus more of a clot.”

In its annual Drugs to Watch report, Clarivate has referred (PDF) to Qfitlia as a “potentially transformative therapy,” and has tabbed its sales potential at $1 billion by 2030.

In phase 3 trials, Qfitlia has shown relatively equal effectiveness in patients with each of the four classifications of hemophilia. It also has performed well across hemophilia patients who altogether underwent 60 major surgeries.

Two phase 3 trials backed the approval, both showing that prophylactic use of Qfitlia could reduce annualized bleeding rate by 90% compared with the control arm. In both studies, patients received nine months of treatment.

In the ATLAS A/B trial, which enrolled 120 non-inhibitor patients with hemophilia A or B who had been previously treated with on-demand clotting factor concentrates, 51% of those who were given a monthly prophylactic dose of Qfitlia had no annual bleeds versus 5% of those who received on-demand clotting factors.

In the ATLAS-INH trial, which enrolled 57 severe hemophilia A and B inhibitor patients, 66% on Qfitlia had no annualized bleeding episodes versus 5% of those in the control group who received an on-demand bypassing agent.

Qfitlia is the second RNA interference drug to score a highly anticipated FDA nod in recent days. Last week, the agency signed off on Alnylam’s Amvuttra to treat transthyretin amyloid cardiomyopathy (ATTR-CM) patients.

Sanofi originally partnered on the development of both Amvuttra and Qfitlia. But in 2018, the companies agreed that Alnylam would take full control of Amvuttra while Sanofi would do the same for Qfitlia.

Both companies struggled to develop fitusiran as it was hit with clinical holds in 2017 and 2020. The first came after a patient died from a blood clot in a phase 2 study. Eventually, Sanofi found a dose that has reduced thromboembolic events.    
 

Sizing up the competition

Despite entering a competitive market with a limited patient population, Qfitlia has a chance to carve out a niche as it has much to offer compared to current factor VIII and factor IX replacement treatments, which are administered intravenously once or twice a week and present the risk of infection.

“The unique advantage of fitusiran—and siRNA technology—is that there’s no need for an IV. It’s a very small-volume subcutaneous injection,” Benson said. “Because it works on the RNA level, it only has to be dosed every other month.”

Qfitlia also holds a convenience edge over two of the most recently approved hemophilia drugs—Novo Nordisk’s Alhemo and Pfizer’s Hympavzi.

Though both can be used by hemophilia A and B patients and both are delivered subcutaneously, Alhemo is dosed daily and Hympavzi is dosed weekly. In addition, Alhemo is limited to inhibitors and Hympavzi is only for non-inhibitors.

With sales of $4.9 billion in 2024, Roche’s hemophilia A treatment Hemlibra is the dominant drug in the indication. It is delivered subcutaneously and can be used by inhibitors and non-inhibitors.

“(Fitusiran) can be kept at room temperature, and the volume is very low. This is the one drug that, from a convenience aspect alone, is actually better than Hemlibra,” a hematologist told Clarivate in its anonymous survey.

Sanofi is not new to the market. It partnered with Sobi on hemophilia A treatment Elocate, which was approved in 2014 and had a solid run before Hemlibra took over as the market leader. 

In 2023, Sanofi and Sobi scored an FDA nod for Elocate follow-on Altuviiio, a prophylactic and rescue medication which has a longer half-life than other factor XIII replacement therapies and is poised to challenge Hemlibra.

Analysts from ODDO BHF project the Altuviio’s sales will reach 1.3 billion euros ($1.4 billion) by 2029. Sanofi expects Altuviiio to be commercially available in April, the company said in a statement.

There are roughly 30,000 people in the U.S. with hemophilia, including approximately a quarter with type B. As an X chromosome-linked condition, it primarily affects males. If untreated, bleeding episodes in the joints can lead to a severe form of hemophilic arthropathy, which may require surgery to repair or replace damaged joints.

https://www.fiercepharma.com/pharma/fda-signs-sanofis-versatile-fitusiran-which-enters-crowded-hemophilia-market