By Michael Dabaie

Pfizer Inc. shares were down 7% to $35.59 in afternoon trading.

The company after the market close Friday updated on the Phase 3 PALLAS trial of Ibrance, or palbociclib, plus endocrine therapy in early breast cancer. Pfizer said the independent Data Monitoring Committee of the collaborative Phase 3 study determined that the trial is unlikely to show a statistically significant improvement in the primary endpoint of invasive disease-free survival.

The PALLAS trial compared palbociclib plus standard adjuvant endocrine therapy to standard adjuvant endocrine therapy alone in women and men with hormone receptor-positive, human epidermal growth factor receptor 2-negative early breast cancer.

J.P. Morgan said that while it had previously highlighted a less than favorable risk/reward into the PALLAS readout, the study was broadly viewed as having a high probability of success and so this early failure represents a meaningful setback for Pfizer.

J.P. Morgan said it still sees a significant opportunity for Ibrance in metastatic disease and forecasts sales increasing to $6.8 billion by 2025 from about $5 billion in 2019. It maintained Pfizer at neutral and lowered its price target to $36 from $37.

Write to Michael Dabaie at michael.dabaie@wsj.com