Although it's never a good idea to try to time the market, there are undoubtedly better times than others when it comes to buying clinical-stage biotech stocks. If you buy too early, for instance, you can end up having to wait years before a company reaches an important clinical milestone, and that could mean enduring multiple rounds of dilution as well. With this theme in mind, I think investors may want to take a close look at the clinical-stage biotechs Galectin Therapeutics (NASDAQ: GALT) and Verastem (NASDAQ: VSTM) heading into next week.