Genentech Inc has issued a warning about patients being treated with its cancer drug Avastin.
The San Francisco-based company reported to the FDA several cases of anemia in patients taking Avastin in a cancer drug trial.
The Food and Drug Administration (FDA) has posted an alert on its Web site. Doctors prescribing the drug for colon, lung, and breast cancers are asked to report any cases of anemia to the FDA or Genentech.
Adverse reports can also be sent to the FDA online on the agency’s MedWatch Voluntary Reporting Form.
Avastin is the company’s blockbuster cancer drug presently being combined with Pfizer Inc’s Sutent in a Phase 1 of a kidney cancer drug trial.
The microangiopathic hemolytic anemia observed in several patients involved in the trial, led to the closure of the trial of the two drugs, which are not approved or recommended to be combined, according to Genentech.
Microangiopathic hemolytic anemia results in a loss of red blood cells.
Two other trials were stopped mid-stage involving the two drugs because of fatigue, gastrointestinal complications and a suppression of blood cells and platelets. Those trials involved patients with breast and lung cancer.
Avastin is approved to treat colon, lung and breast cancer. And with quarterly sales of $640, Avastin is expected to be Genentech’s most important drug. The drug works by cutting of the supply of blood to tumors.
Sutent treats advanced kidney cancer.
In the letter by Genentech posted on the FDA Web site, the company said that five of 12 patients who were treated with the highest dose of Sutent have been diagnosed with microangiopathic hemolytic anemia.
Two of the most severe cases were reversed with three weeks of therapy and a discontinuation of the drugs.
Avastin will be combined with other therapies to be used in other trials.
Shares of Genentech fell 2 percent last week after reports questioned whether Avastin is worth its high price - generally costing an estimated $100,000 per patient a year. #