Xspray Pharma has received yet another Complete Response Letter from the U.S. Food and Drug Administration, further delaying approval of its leukemia drug candidate Dasynoc.
The setback marks the latest in a series of rejections for Dasynoc, an optimised version of Bristol Myers Squibb’s cancer treatment Sprycel, known generically as dasatinib.
Dasynoc is being developed to treat chronic myeloid leukemia and acute lymphoblastic leukemia, two serious blood cancers with significant unmet patient needs.
The FDA’s latest letter addressed “previously communicated” manufacturing observations at Xspray’s third-party production partner, NerPharMa, an Italy-based contract manufacturer.
Regulators also requested additional commercial-scale batch data from the company, following earlier corrective actions that had already been undertaken at the NerPharMa facility.
NerPharMa has completed remediation efforts at its site and informed the FDA of its progress, though Xspray acknowledged the agency has yet to determine whether a reinspection is required.
This mirrors last October’s rejection, when the FDA similarly flagged concerns with the same manufacturing partner, prompting then-CEO Per Andersson to call the delays “unfortunate.”
Xspray CEO Blake Leitch said in a statement: “The CRL confirms that the remaining uncertainty is now linked to NerPharMa sufficiently addressing the FDA’s observations at their manufacturing site and batch data from consecutive manufacturing runs being provided.”
Leitch added: “As expected, this will require an NDA resubmission.”
Xspray said it plans to resubmit its Dasynoc application before the end of 2026, prioritising production of additional commercial-scale batches to satisfy the FDA’s data requirements.
The company stressed that the FDA raised no concerns relating to clinical data, bioequivalence, or stability in the latest rejection letter.
Xspray also confirmed that a medication error risk cited in previous rejections “has been resolved,” removing one significant obstacle that had plagued the application since its earliest submission.
Dasynoc has now received Complete Response Letters in 2023, 2024, and again in 2026, each time facing hurdles related to manufacturing or labelling rather than the drug’s underlying clinical profile.
Blake Leitch was appointed CEO in February 2026, with predecessor Per Andersson transitioning to the role of chief scientific officer to support Xspray’s push toward becoming a commercial-stage company.
Xspray, headquartered in Sweden, operates using its proprietary HyNap platform, which the company uses to design what it describes as “improved versions” of cancer-fighting protein kinase inhibitor drugs.
Beyond Dasynoc, the company’s pipeline includes Nilopki, an optimised version of Novartis’ Tasigna, which is also currently under FDA review.
Xspray is additionally developing optimised versions of Pfizer’s Inlyta and Exelixis’ Cabometyx, broadening its oncology-focused portfolio.
The company says it will continue preparing for a U.S. Dasynoc launch, aiming to make the product available to patients as quickly as possible once regulatory approval is secured.
Xspray’s stock fell sharply following news of the latest FDA rejection, reflecting investor frustration over repeated manufacturing-related delays.