Personal-genomics company 23andMe, based in Mountain View, California, and biotechnology firm Genentech, based in San Francisco, are recruiting patients with breast cancer to study genetic predictors of how well they respond to the drug Avastin (bevacizumab).

Genentech’s Avastin is approved to treat several cancers, but in November, the US Food and Drug Administration (FDA) revoked approval to use the drug in certain breast cancers that have metastasized, or spread beyond the initial site of the tumour. The decision came in light of studies done after the drug’s 2008 approval for breast cancer that found, the FDA said, “only a small effect on tumor growth without evidence that patients lived any longer or had a better quality of life compared to taking standard chemotherapy alone — not enough to outweigh the risk of taking the drug.”

Genentech said at the time that it would look for potential biomarkers that could identify the groups of patients with breast cancer who would be most likely to benefit from taking the drug.

23andMe has been turning increasingly towards research studies as consumer demand for its services has plateaued.

23andMe is seeking DNA donations from individuals with metastatic breast cancer who have taken Avastin; in return, it will grant them access to its genome-profiling service. Patient groups are supporting the study.