Compounds of Formula I: (I) in which A, A1, R1, R7a, R7b, R8 and R10 have the meanings given in the specification, are DP2 receptor inhibitors useful in the treatment of useful in the treatment and prevention of immunologic diseases, allergic diseases such as asthma, allergic rhinitis and atopic dermatitis, and other inflammatory diseases mediated by prostaglandin D2 (PGD2). The compounds of Formula I may also be useful in treating diseases or medical conditions involving the Th2 T cell via production of IL-4, IL-5 and/or IL-13.