The Broad Stroke of Hsp90 Inhibitors: Painting over the RAF Inhibitor Paradox

Abstract

The novel Hsp90 inhibitor XL888 is undergoing clinical investigation for use in conjunction with the rapidly accelerated fibrosarcoma (RAF) kinase inhibitor vemurafenib to treat unresectable melanoma. The addition of XL888 to current regimens may serve an additional purpose by blocking the RAF inhibitor paradox. Such activity could reduce adverse events in patients and provide a biomarker for the successful inhibition of Hsp90 target proteins.