Pfizer wins four Zithromax label updates in one week; two Phase 2 trial results also posted

Pfizer had four FDA label approvals and two Phase 2 study results posted this week, spanning an established antibiotic and pipeline compounds in breast cancer and cicatricial alopecia.

• The FDA approved Supplement 40 to Zithromax's NDA050784, covering an oral tablet with azithromycin at a strength equivalent to 500MG base¹, with a submission status date of 2026-07-13.
• The FDA approved Supplement 52 to Zithromax's NDA050733, covering an injectable formulation of azithromycin at 500MG base per vial², also dated 2026-07-13.
• The FDA approved Supplement 53 to Zithromax's NDA050711, covering an oral tablet with azithromycin at a strength equivalent to 250MG base³, with the same status date.
• The FDA approved Supplement 54 to Zithromax's NDA050710, covering oral suspension formulations of azithromycin at strengths of 100MG base per 5ML and 200MG base per 5ML⁴, also dated 2026-07-13.
• A Phase 2 study of PF-07220060 plus letrozole versus letrozole alone in postmenopausal women is completed. The trial enrolled participants confirmed to have Hormone receptor (HR) positive, Human epidermal growth factor receptor 2 (HER2) negative breast cancer.⁵ Primary completion was listed as 2025-07-10, results were first posted 2026-07-15, enrollment reached 121 participants, and the primary outcome was Percentage of Participants With Complete Cell Cycle Arrest (CCCA) at Day 14⁵.
• A Phase 2 study of ritlecitinib in cicatricial alopecia is completed, sponsored by Emma Guttman with Pfizer as a collaborator⁶. Primary completion was listed as 2025-03-20, results were first posted 2026-07-15, enrollment reached 50 participants, and the primary outcome tracked Change in Ct Values of mRNA Levels of CCL5 gene expression in skin biopsies from baseline to week 24⁶.