PDUFA Dates: September 2026

Spinal muscular atrophy — a genetic motor-neuron disease where many patients still plateau with residual muscle weakness even on today's SMN-targeted therapies.

Apitegromab is an anti-myostatin antibody that works on muscle rather than the SMN gene defect that causes spinal muscular atrophy. Existing therapies — nusinersen, risdiplam and onasemnogene — restore SMN protein but do not directly rebuild muscle; apitegromab is designed to be added on top to improve motor function. Scholar Rock resubmitted the BLA on March 31, 2026 after a September 2025 Complete Response Letter, and the FDA granted Priority Review with a target action date at the end of September. The filing rests on the Phase 3 SAPPHIRE trial and also carries Fast Track, Orphan Drug and Rare Pediatric Disease designations. Watch whether the second-round review clears the issues that drove the CRL.

Advanced ROS1-positive non-small cell lung cancer in patients whose tumors have already progressed on one or more ROS1-targeted therapies.

Zidesamtinib is Nuvalent's selective ROS1 inhibitor, engineered to stay active against the resistance mutations that emerge on earlier TKIs and to penetrate the brain, where ROS1-positive lung cancer frequently spreads. The NDA covers TKI-pretreated patients — a setting with few durable options once first-line ROS1 drugs fail. The application is based on the ARROS-1 trial and is under standard review. The FDA granted Breakthrough Therapy designation specifically for patients previously treated with two or more ROS1 TKIs, plus Orphan Drug status. With a September 18 target date, watch the depth and durability of responses in the pretreated and CNS-metastatic subgroups that define the unmet need.

Dermatomyositis — a rare, often debilitating autoimmune disease that inflames muscle and skin and is still largely managed with steroids and broad immunosuppression.

Brepocitinib is an oral dual TYK2/JAK1 inhibitor from Priovant, a Roivant company, aimed at the interferon-driven inflammation central to dermatomyositis. Most patients today rely on corticosteroids, conventional immunosuppressants and IVIG; a targeted oral agent that dials down the specific signaling pathways behind the disease would be a meaningful addition. The NDA is built on the Phase 3 VALOR study and carries an unusually strong regulatory package — Breakthrough Therapy, Orphan Drug and Priority Review. Priovant has guided a commercial launch by the end of September 2026. Watch how broad the eventual label is and how strongly the functional and skin endpoints read out.

Previously treated cholangiocarcinoma — bile-duct cancer driven by FGFR2 fusions or rearrangements, a hard-to-treat group with few good second-line options.

Lirafugratinib is a selective, irreversible FGFR2 inhibitor (originally Relay Therapeutics' RLY-4008) now carried in the US by Elevar Therapeutics. Unlike the pan-FGFR inhibitors already approved in this setting, it is designed to hit FGFR2 specifically and spare FGFR1, the source of much of the off-target toxicity that limits dosing. The NDA targets second-line FGFR2 fusion/rearrangement-positive cholangiocarcinoma and is supported by the Phase 1/2 ReFocus trial, which showed a confirmed objective response rate of 46.5%. The FDA granted Priority Review with a target date of September 27. Watch whether the selectivity translates into cleaner tolerability than existing FGFR drugs without giving up efficacy.