Biotech giant Genentech put participants in its human trials for a cancer drug at risk by not following clinical rules and fired a high-level employee who questioned why the company was racing toward the approval deadline, according to a lawsuit filed by the worker who said she was targeted for whistle-blowing. The suit filed in San Mateo County Superior Court by Juliet Kniley, a former senior clinical program manager at Genentech, alleges she was harassed, demoted and eventually let go after questioning the company’s failure to follow federal guidelines governing clinical trials.