The present invention relates to azaindole acetic acid derivatives of formula (I),wherein R1 and R2 are as described in the description and their use as prostaglandin receptor modulators, most particularly as prostaglandin D2 receptor modulators, in the treatment of various prostaglandin-mediated diseases and disorders, to pharmaceutical compositions containing these compounds and to processes for their preparation.本發明係關於式(I)之氮雜吲哚乙酸衍生物,其中R1及R2為如說明書中所述,及其作為前列腺素受體調節劑、最特別作為前列腺素D2受體調節劑在治療各種前列腺素介導疾病及病症之用途,含有此等化合物之醫藥組合物及其製備方法。