Shares of AstraZeneca (AZN) experienced a 1.5% decline following the FDA's rejection of its subcutaneous injection form of the Saphnelo lupus drug. The rejection, communicated via a complete response letter, indicates the application cannot be approved in its current state. The company is now working to address the FDA's concerns.

This setback impacts AstraZeneca's plans for wider market access for Saphnelo. The drug, already approved in intravenous form for treating systemic lupus erythematosus (SLE), is available in over 70 countries. The subcutaneous form offers patients a more convenient administration method. The EU approved the subcutaneous form in December 2025.

AstraZeneca is expected to receive a decision on the updated application in the first half of 2026. The original application was based on a Phase III trial, showing the subcutaneous administration met the primary endpoint. Despite the US rejection, the company remains committed to advancing the application.

Investors should watch for further updates on the resubmitted application. The company will need to address the FDA's concerns to gain approval for the subcutaneous form. Success would provide a more convenient treatment option for patients and potentially boost AstraZeneca's market share in the lupus drug sector.