FDA rejects Xspray's would-be rival to Bristol Myers' Sprycel on dosing, manufacturing concerns

With Xspray Pharma and Eversana’s cancer med hitting a regulatory setback, a launch in the second half of 2023 now looks unlikely. That’s good news for Bristol Myers Squibb, which has secured a few more competition-free months for its aging leukemia blockbuster Sprycel.

Swedish drugmaker Xspray has received an FDA complete response letter on its application for its first product Dasynoc. In issuing the rejection, the FDA requested additional information on the drug's dosing plus greater clarity around a third-party manufacturing facility.

Xspray is seeking an FDA nod for Dasynoc to treat chronic myeloid leukemia (CML) and acute lymphatic leukemia (ALL).

Despite issuing the rejection, Xspray said the FDA signed off on “critical aspects” of the application and did not identify any deficiencies pertaining to the drug’s stability or clinical data, the company said in a release Tuesday.

Xspray is positioning its drug as a rival to BMS’ Sprycel, which clinched its first approval in CML back in 2010. This past February, Xspray unveiled a commercialization pact with Eversana to support the U.S. launch and sale of Dasynoc, which the parties had hoped to debut by the second half of 2023.

Xspray and Eversana are pitching Dasynoc as a new and differentiated treatment option for CML and ALL in the $3.5 billion U.S. market for tyrosine kinase inhibitors.

While celebrating the FDA’s acceptance of Dasynoc’s stability and clinical profile, Xspray CEO Per Andersson noted that his company will work with the U.S. drug regulator and its third-party production facility to “ensure a swift handling of the outstanding questions.”

The FDA rejection relates to all six strengths of the drug (15 mg, 36 mg, 50 mg, 57 mg, 70 mg and 100 mg), Xspray explained in the release. The complete response letter asks Xspray to furnish the FDA with additional information for doctors and patients to “avoid confusion about the proper dosing of Dasynoc."

Further, an agency review of Xspray’s third-party manufacturing plant remains ongoing, the company added.

Xspray stressed that it will “promptly compile” all information requested by the FDA.

Dasynoc is designed not to interfere with proton pump inhibitors (PPIs), giving it a potential leg up on Sprycel, which has a label that states it should not be used in tandem with H2 antagonists or PPIs. Further, Xspray says its drug is bioequivalent to Sprycel at a 30% lower dose, offering "better precision and predictability of dosing.”

In anticipation of the drug’s potential approval and launch, Xspray in February enlisted commercial services outfit Eversana to help market its first commercial product stateside. Under the deal, Xspray is poised to maintain financial and strategic control over the leukemia med while leveraging Eversana’s commercialization team and TKI marketing know-how. Xspray says it hopes the partnership will abbreviate Dasynoc’s rollout and “optimize” the budget for the product’s debut.

Further, Eversana will help support Xspray with market access, agency services, clinical and commercial field teams, medical science liaisons, patient services and compliance.

Apart from the FDA complete response letter, Dasynoc’s launch hinges on litigation around patents for crystalline forms of dasatinib, the generic name for BMS’ Sprycel. Regarding the intellectual property litigation, Xspray has said it’s “confident” those dasatinib presentations don’t occur in its product.

Despite the company’s confidence in the lawsuit, a U.S. district court in April denied Xspray’s motion to dismiss the case, which was brought by BMS in February 2022. 

While Sprycel may be showing its age, the TKI medicine continues to bring home blockbuster sales for BMS. Last year, the med reeled in $2.16 billion in revenues.

Across the pond, a European court decision paved the way for Sprycel generics in 2017. Back home in the states, BMS has sued competitors like Alembic over their efforts to roll out copycat versions of the cancer blockbuster. In the U.S., Sprycel is protected by a pair of patents that are expected to run out in August 2025 and September 2026, according to the FDA Orange Book. 

As for other TKIs against leukemia, Sprycel also competes with the likes of Novartis' Scemblix and Takeda's Iclusig.