Suggest Precautions To Be Taken While On Sprycel

My daughter s husband has been diagnosed with CML. He started taking Gleevec but stopped responding to that med and is now on Sprycel. At the time, I searched WebMD on both drugs and never found any warning about the cross-contamination (for lack of a better term) through unprotected sex. But on Drugs.com I read today under the paragraphs about What should I avoid while taking Sprycel? , that one should use condoms during sexual activity to avoid exposure to body fluids . Is this true? Is my daughter in danger? If so, what possible dangers?