FDA Issues Complete Response Letter for Lantheus’ LNTH-2501 PET Imaging Kit for Neuroendocrine Tumors

Lantheus Holdings has received a Complete Response Letter (CRL) from the U.S. Food and Drug Administration (FDA) for its New Drug Application (NDA) seeking approval of LNTH-2501 (Gallium 68 edotreotide), an investigational positron emission tomography (PET) imaging kit for detecting somatostatin receptor-positive (SSTR+) neuroendocrine tumors (NETs).

The FDA informed the company that it could not approve the application by the Prescription Drug User Fee Act (PDUFA) target date of June 29, 2026, because unresolved inspection-related deficiencies remain at a third-party manufacturing facility responsible for producing the drug product. The agency stated that approval will require satisfactory resolution of these manufacturing conditions.

The CRL did not identify any deficiencies in the clinical package submitted by Lantheus and raised no concerns regarding the safety or efficacy of LNTH-2501.

Investigational PET Imaging Agent for SSTR-Positive Neuroendocrine Tumors

LNTH-2501 is an investigational radioactive diagnostic kit used to prepare Gallium-68 edotreotide injection for PET imaging. The radiotracer binds to somatostatin receptors, which are highly expressed in many neuroendocrine tumors, enabling physicians to localize disease with high sensitivity.

The product is intended for use in both adult and pediatric patients with suspected or confirmed somatostatin receptor-positive NETs. It is supplied as a two-vial kit that allows radiopharmacies to prepare Ga 68 edotreotide directly using Gallium-68 obtained from an on-site generator, supporting local radiopharmaceutical production without centralized manufacturing of the final radiotracer.

Accurate molecular imaging plays a critical role in diagnosing neuroendocrine tumors, determining disease extent, selecting appropriate treatment strategies, and monitoring patients over time.

 Regulatory Review Focused on Manufacturing Compliance

The FDA’s decision was based exclusively on unresolved manufacturing observations at the third-party production facility rather than the scientific or clinical merits of the application. Such facility-related CRLs are relatively common during regulatory review and generally require corrective actions and successful reinspection before approval can proceed.

Mary Anne Heino, Executive Chairperson and Chief Executive Officer of Lantheus, said the company remains confident in LNTH-2501 and emphasized that the FDA’s feedback relates solely to the external manufacturing partner rather than the product’s clinical performance. She added that the company is working closely with both the manufacturing partner and the FDA to resolve the inspection findings and move the application forward.

Path Forward

Lantheus has not disclosed a revised regulatory timeline. The company will work with its third-party manufacturing partner to address the FDA’s inspection-related observations before resubmitting the NDA or providing additional information requested by the agency.

If approved, LNTH-2501 could expand the available PET imaging options for patients with somatostatin receptor-positive neuroendocrine tumors, offering radiopharmacies a kit-based preparation method that supports broader clinical access to Ga 68 edotreotide imaging. Until then, the product remains investigational and is not approved for commercial use in the United States.

Reference

Lantheus Receives Complete Response Letter from FDA for LNTH-2501 (Ga 68 edotreotide) | Lantheus Holdings, Inc.