The FDA just handed this clinical-stage biotech its golden ticket -- but at a $4.3 billion valuation, the market's already pricing in a fair amount of commercial success.Crinetics Pharmaceuticals (CRNX 27.92%) faces the ultimate biotech paradox: Its newly approved drug Palsonify could either justify the stock's $4.3 billion valuation or expose it as dangerously overpriced. The U.S. Food and Drug Administration (FDA) approval on Sept. 25 transforms this clinical-stage company into a commercial powerhouse wit ...