The Food and Drug Administration has stated that it is reviewing new data that provide further evidence of the risks of anemia drugs manufactured by Amgen Inc and Johnson & Johnson that are administered to cancer patients.

The main anemia drugs reviewed by the FDA are Amgen’s Aranesp, Epogen and Johnson & Johnson’s Procrit also known as eythropoiesis-stimulating agents or ESAs.

A study conducted by Amgen revealed that patients with breast cancer or advanced cervical cancers who were on anemia drugs had 14 percent higher rate of dying or had more rapid tumor growth as compared to 9.8 percent in the placebo group. The study that revealed these data had 733 patients who received chemotherapy and surgery for breast cancer.

“FDA is reviewing these data and may take additional action. In the meantime, FDA recommends that health care providers review the risks and benefits of ESAs outlined in the product label and discuss this information with their patients," said in a statement FDA Deputy Commissioner Janet Woodcock.

Another study of women with cervical cancer showed 66 percent of patients not being on treatment with Procrit were alive and free of cancer growth, compared with 58 percent of those taking the drug.

Erythropoiesis-stimulating agents are drugs synthetically engineered from a natural protein produced by kidney. This protein is responsible for stimulating the bone marrow to manufacture more red blood cells. The FDA approved these drugs in chronic kidney failure and in cancer patients who have anemia because of chemotherapy.

This is not the first time when the FDA reviewed the drugs. In March and November last year, the health agency revised boxed warnings to reflect new data on health risks posed by these drugs. They already contain a blackbox warning due to their cancer risk.

An FDA advisory committee will discuss the new data and revisit the drugs’ risks and benefits in the next few months.

Both Amgen and Johnson & Johnson said they would continue to work closely with the FDA on any additional label updates. Moreover, they would continue to provide safety updates to health-care providers.

Shares of Amgen Inc. rose 44 cents Thursday to $46.13 in after-hours trading, following an earlier close at $45.69. Johnson & Johnson shares rose 2 cents to close at $65.93.