As several new JAK inhibitors threaten Incyte’s bread-and-butter Jakafi in myelofibrosis, the company is busy advancing new regimens ahead of the drug’s 2028 patent cliff.
Two recently launched JAK inhibitors “haven’t really moved at all over many quarters” in terms of market share or net sales, Barry Flannelly, Incyte’s North America general manager, said on the company's third-quarter conference call Tuesday.
The two drugs are Bristol Myers Squibb’s Inrebic and CTI BioPharma’s Vonjo, approved by the FDA in 2019 and February 2022, respectively. Inrebic collected $29 million sales in the third quarter, while Vonjo generated $12 million in the second quarter.
By comparison, Jakafi recorded $636 million in sales in the third quarter, although the number missed analysts’ expectations by 5%. Incyte attributed the relatively weak showing to decreased channel inventory by the end of September, while stressing that the underlying demand continued to grow.
The Jakafi performance came as the FDA in mid-September approved another JAK inhibitor, GSK’s Ojjaara, for anemic myelofibrosis patients regardless of the line of treatment. Analysts view Ojjaara’s line-agnostic label a major threat to Jakafi.
Still, Jakafi remains the only drug to have shown superior overall survival in myelofibrosis regardless of the patient’s anemia status. The Incyte drug is so far the most effective therapy for managing symptoms and reducing the size of the spleen, Flannelly noted.
“That strong designation gives us confidence that we’ll continue to be the leader in myelofibrosis,” Flannelly said of Jakafi’s overall survival benefit.
In addition, Jakafi's myelofibrosis label boasts no line restrictions or anemia status requirements.
For Ojjaara, GSK is targeting patients with anemia, which Jakafi could worsen during its treatment of myelofibrosis. But Flannelly played down that threat by pointing to a very low rate of treatment discontinuation because of anemia in Jakafi’s clinical trials.
Given Ojjaara’s label, anemic patients might go directly to the GSK drug as their initial treatment option rather than wait until they can no longer take Jakafi. By GSK’s estimate, about half of the first-line myelofibrosis population are anemic at diagnosis.
Flannelly noted that GSK priced Ojjaara higher than Jakafi.
“It seems like [Ojjaara] was priced for a second-line drug, and we think that’s where it’ll be mostly used,” the Incyte exec said.
While playing defense against new rivals in myelofibrosis, Incyte believes the rare blood disorder polycythemia vera will serve as Jakafi’s main growth driver in the future. The optimism was buoyed by a new clinical showing that Jakafi reduced the risk of major thrombosis by 44% over best available therapy for patients who can’t take hydroxycarbamide.
Meanwhile, investors remain concerned about Jakafi’s upcoming loss of exclusivity in 2028. Incyte’s plan to introduce an extended-release version that would reduce Jakafi’s dosing to once daily from twice daily was recently rejected by the FDA.
Incyte is still working with the FDA on its response to the March rejection, the company’s R&D head Pablo Cagnoni said on Tuesday’s call. Incyte believes it can resolve the agency's concerns “way before” the patent cliff, he said.
Novel combinations represent another strategy Incyte is banking on. The company will have monotherapy and Jakafi combo data for its ALK2 inhibitor zilurgisertib and BET inhibitor INCB57643 at the upcoming American Society of Hematology annual meeting in December. Cagnoni said Incyte will share more about its registrational trial plans after the event.