Novel thalidomide analogues display anti-angiogenic activity independently of immunomodulatory effects

The anti-tumour effects of thalidomide have been associated with its anti-angiogenic proper-ties. Second generation thalidomide analogues are distinct compounds with enhanced therapeutic potential. Although these compounds are beginning to enter trials for the treatment of cancer there is very little information regarding the anti-angiogenic activity of these clinically relevant compounds. Furthermore, it is not known how the various immunomodulatory activities of these compounds relate to anti-angiogenic activity. In this study we assessed the anti-angiogenic activity of compounds from both IMiD(TM) and SelCID(TM) classes of analogues using a novel in vitro multicellular human assay system and the established rat aorta assay. Our results show that both the IMiDs and SeCIDs tested are significantly more potent than thaliclomide. The anti-angiogenic potency of the analogues was not related to inhibition of endothelial cell proliferation, nor their TNF-alpha/PDE type 4 inhibitory properties. However, anti-migratory effects in vitro and inhibition of tumour growth in vivo was observed with the analogue IMiD-I (clinically known as REVIMID(TM)). Our results show that anti-angiogenic activity spans both currently defined classes of thalicomide analogue and is not related to their previously described immunomodulatory properties. Identification of the differential effects of these compounds will enable targeting of such compounds into the appropriate clinical setting. (C) 2002 Cancer Research UK.