** Brokerage Stifel starts coverage on drug developer Palvella Therapeutics PVLA.O with "buy" rating and $45 PT

** New PT represents a 65% upside to the stock's last close

** Stifel thinks PVLA has the potential to build a portfolio of rare skin disease treatments, "which collectively could have multi-billion-dollar potential"

** Stifel notes co's gel QTORIN optimizes for delivery of the treatment into the deepest regions of the skin with potency and high patient tolerability

** Including session's moves, PVLA stock more than doubled YTD

(Reporting by Padmanabhan Ananthan)

((Padmanabhan.Ananthan@thomsonreuters.com;))