Rigel Pharmaceuticals Inc and Serono have signed an agreement under which Serono has been granted an exclusive license to develop and commercialise product candidates from Rigel's Aurora kinase inhibitor programme. The license is worldwide, except for Japan, which Serono has an option to include at any time within the next two years.

Rigel's Aurora kinase inhibitor programme includes R763, for which Rigel expects to file an investigational new drug (IND) application in December 2005. R763 is a highly potent, orally available multi-Aurora kinase inhibitor that has been shown in vitro and in vivo tumour xenograft models to inhibit proliferation and trigger apoptosis in several tumour cell lines including the cervix, colon, lung, pancreas and prostrate.

Under the terms of the agreement, Rigel will receive initial payments totaling $25 million, comprised of a license fee of $10 million and purchase of $15 million of Rigel's common stock, at a premium to the market price. With additional development and sales-based milestone payments for R763, Rigel could receive up to $160 million in total, as well as royalties on any eventual product sales of R763 and other Aurora kinase inhibitors developed under the agreement, states a company release.

Serono will be responsible for the further development and commercialisation of R763, as well as any other product candidates arising from Rigel's Aurora kinase inhibitor programme.


"Serono has been extraordinarily proactive in building and advancing its portfolio in oncology. R763 is a potent, selective inhibitor of Aurora kinase and fits well into Serono's oncology strategy. We are confident that Serono will be equally proactive in realising the potential of this product candidate," said Donald G Payan, executive vice president and chief scientific officer of Rigel.

The over-expression of Aurora kinase can cause cells to rapidly develop an abnormal number of chromosomes. Elevated levels of Aurora kinase are frequently associated with various human cancers, such as cancers of the breast, bladder, colon, ovary, head and neck, and pancreas. Inhibition of Aurora kinase arrests cell division and promotes programmed cell death (apoptosis). Increased knowledge of Aurora kinase and its regulation may result in future treatments for cancer.

Rigel's lead oncology drug candidate, R763, is a highly potent inhibitor of Aurora kinase, that has been shown to potently inhibit proliferation and trigger apoptosis in several tumour cell lines including cervix, colon, lung, pancreas and prostate. Rigel discovered R763 using its proprietary cell-based PAD assays applied to tumour cell lines.