Xolair and Cancer: Does the Medication Increase Your Risk?

There has been some concern over a potential association between the medication Xolair (omalizumab) and cancer. Prior to Xolair being approved for use in the United States, the original FDA safety officer's report included the following passage:

"Comparisons of malignancy rates suggest (but do not establish) an increased rate for Omalizumab-exposed subjects ... Comparisons of the clinical study data to a large epidemiological database suggested Omalizumab-exposed subjects experienced more malignancies than expected while the control group experienced fewer malignancies."

Possible Links

In clinical trials, cancers were seen in one of every 200 Xolair-treated study volunteers (20 of 4127 patients) compared to one of every 500 control volunteers who did not take Xolair (5 of 2236 patients). The cancers were of various types. The cancers that occurred more than once in this group included:

There were five other cancers that each occurred one time.

It is important to realize that if someone had cancer before participating in the Xolair studies, they were not excluded from the study - in fact, it is thought that at least 5 patients had symptoms of cancer before participation in the clinical trial. As a result, it would be very unlikely that Xolair caused cancer in these patients.

Patients also developed the cancers in a very short period of time after beginning treatment with Xolair. It is unlikely that the cancers would have grown in such a short time period -- meaning, they may already have been developing cancer before starting Xolair.

Subsequently, a panel of oncologists has stated that it does not feel that Xolair treatment causes cancer based on currently available data.

Long-Term Use

The impact of longer exposure to Xolair or its use in people at higher risk for cancer (such as smokers or those with a family history of cancer) is not known but is undergoing further study. The Epidemiologic Study of Xolair (omalizumab): Evaluating Clinical Effectiveness and Long-Term Safety in Patients with Moderate-to-Severe Asthma will examine the long-term effects of Xolair related to various types of cancers.

A 2014 review of 5-year safety data for Xolair found no difference in cancer rates between Xolair patients and those who were not being treated with Xolair. The drug has also been associated with mini-strokes known as transient ischemic attacks. Heart attacks; sudden, unexpected chest pain; high blood pressure in the arteries of the lungs called pulmonary hypertension; and blood clots in the lungs and veins. However, the FDA is not able to say whether or not Xolair contributes to these problems or not based on their assessment of the currently available evidence. Because the FDA is not able to definitively state there is an absence of risk related to these heart and brain problems, the FDA added them to the package insert in the Adverse Reactions section of the drug label. Similarly, the FDA is unable to definitively say there is not a risk of cancer with Xolair, so information discussing this topic was added to the Warnings and Precautions section of the drug label. If you are going to consider Xolair as a treatment for your or your child's asthma you should discuss these issues with your doctor.

The FDA suggests that doctors periodically reassess the need for continued Xolair therapy based on the patient’s disease severity and level of asthma control.

Was this page helpful?

Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.