"Merck said data shows the drug is not capable of inducing genetic changes in human cells, but men in its trials have to abstain from heterosexual intercourse or agree to use contraception."
Exclusion Criteria from the IPIX trial: Sexually active males with female partners of childbearing potential unwilling to use a condom when engaging in intercourse of reproductive potential throughout the study and for up to 30 days after stopping treatment.
See the difference? I don't. Because there isn't one.