On Wednesday, the FDA gave Pfizer Inc. (Pfizer (PFE)) a green light for its blockbuster cancer drug Ibrance (palbociclib) in a new setting: frontline maintenance for metastatic breast cancer. Specifically, the approval covers Ibrance in combination with trastuzumab (with or without pertuzumab) and endocrine therapy for the maintenance treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-positive (HER2+) locally advanced or metastatic breast cancer, following induction treatment.

This is a notable expansion for Ibrance, which has been a go-to first-line therapy for HR+, HER2- metastatic breast cancer since its initial approval in 2015. The drug has been prescribed to more than 900,000 patients and is approved in over 100 countries. Now, it's stepping into the HER2+ arena, where it could become a new standard for maintenance therapy.

The approval is based on positive results from the Phase 3 PATINA trial, sponsored by Alliance Foundation Trials, LLC. The study showed that adding Ibrance to anti-HER2 therapy (trastuzumab or trastuzumab plus pertuzumab) and endocrine therapy reduced the risk of progression or death by 24% compared to anti-HER2 and endocrine therapy alone. That's a meaningful improvement for patients who have already completed induction treatment and need to keep the cancer at bay.

Pfizer has had a busy week beyond the Ibrance news. Earlier, the company reported mixed topline results from its Phase 3 SigVie-002 trial of sigvotatug vedotin, an investigational antibody-drug conjugate for previously treated advanced non-squamous non-small cell lung cancer. The study missed its primary overall survival endpoint in the broader patient population, though it showed encouraging signals in second-line patients. Not a home run, but not a total strikeout either.

In corporate news, Pfizer announced in June that CFO Dave Denton will step down on August 15 to move into the consumer goods industry. Cecile Guegan will take over as interim CFO on August 16 while the company searches for a permanent successor. CEO Albert Bourla noted that Denton helped guide major transactions, including the acquisitions of Seagen, Biohaven, and Metsera.

As for the stock, Pfizer shares were up 0.96% at $24.27 in premarket trading on Thursday, reflecting a modest positive reaction to the Ibrance approval.