AstraZeneca's breast cancer trial flops as Scholar Rock secures FDA nod for SMA drug

AstraZeneca reported that camizestrant, a breast-cancer pill tested as a first-line option for advanced tumors, failed to show longer progression-free survival when paired with a partner drug, missing the trial’s primary goal and potentially limiting its market beyond the accelerated-approval niche for a specific tumor mutation. The setback follows the drug’s recent accelerated approval in the United States. In a separate development, Scholar Rock secured U.S. Food and Drug Administration clearance for Isembyld, the inaugural therapy aimed at counteracting muscle loss in spinal muscular atrophy.

Isembyld is authorized for adults and children two years and older who are already receiving SMN2-targeted SMA treatments, offering a new avenue to improve mobility for patients with this rare, progressive disorder. The FDA decision marks progress for SMA care, while AstraZeneca’s trial failure underscores the challenges of expanding oncology drug indications.