Larotaxel (XRP9881) is a taxane analogue with preclinical activity against taxane-resistant breast cancer. Larotaxel (XRP9881) exerts its cytotoxic effect by promoting tubulin assembly and stabilizing microtubules, ultimately leading to cell death by apoptosis. It presents the ability to cross the blood brain barrier and has a much lower affinity for P-glycoprotein 1 than Docetaxel[1][2][3].

[1]. Diéras V, et al. Phase II multicenter study of larotaxel (XRP9881), a novel taxoid, in patients with metastatic breast cancer who previously received taxane-based therapy. Ann Oncol. 2008 Jul;19(7):1255-60. [2]. Morris PG, et al. Novel anti-tubulin cytotoxic agents for breast cancer. Expert Rev Anticancer Ther. 2009 Feb;9(2):175-85. [3]. Zatloukal P, et al. Randomized multicenter phase II study of larotaxel (XRP9881) in combination with cisplatin or gemcitabine as first-line chemotherapy in nonirradiable stage IIIB or stage IV non-small cell lung cancer. J Thorac Oncol. 2008 Aug;3(8):894-901.