Oops: Pfizer halts cancer drug experiments after too many people die

Drug maker Pfizer (PFE) said late Tuesday that it will discontinue research on an experimental lung cancer drug after side effects led to an unexpected number of deaths in patients.

Pfizer said it was canceling enrollments for Phase 3 clinical trials for the drug, which was known as figitumumab. The compound was being used in treatment for a disease known non-adenocarcionoma, nonsmall-cell lung cancer.

According to Pfizer, the committee monitoring the clinical trials said in September it saw a “apparent imbalance” in serious side effects when using the drug, including fatalities.

Pfizer said it would continue to study the drug for use in other cancer treatments, including prostate and breast cancer and Ewing’s sarcoma.

Figitumumab belongs to a class of drugs called IGF-1R inhibitors that may block substances in the body that stimulate growth of cancer cells. The Wall Street Journal said that analysts expected that if successful, this compound could have resulted in $1 billion in sales for the company by 2015.

Shares of Pfizer were down 0.2% to $18.53 on Wednesday in a lightly traded session.