Compounds of formula (I) in free or pharmaceutically acceptable salt form, where R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, m, n, w, X, and Y have the meanings as indicated in the specification, are useful for treating conditions mediated by the CRTh.sub.2 receptor, especially inflammatory or obstructive airways diseases.