Leo said over 500K in the PR, so I know the number was conservative. With more and more immunotherapies being approved, the need for B-OM as a preventative increases because oral mucositis is a common side effect.

"The most common side effects of immunotherapy include:

Mouth sores. Immunotherapy can damage the cells inside the mouth and throat. This causes painful sores in these areas, a condition called mucositis. These sores can get infected. Mouth sores usually happen 5 to 14 days after a treatment."

http://www.cancer.net/navigating-cancer-care/...unotherapy