abstract |
The invention provides compounds of Formulas Ia-Ib, stereoisomers or pharmaceutically acceptable salts thereof, wherein A, X, R 1 , R 2 , R 4 , R 5 and R 16 are defined herein, a pharmaceutical composition that includes a compound of Formulas Ia-Ib and a pharmaceutically acceptable carrier, adjuvant or vehicle, and methods of using the compound or composition in therapy. |