Compounds of the formula Ia or Ib: ##STR00001## wherein A, B, X, Y, Z, W, k, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are those defined herein, and compositions comprising the same. The present invention also provides methods for preparing compounds of formula I and using the same in treating p38 mediated disorders in a subject.