Merck & Co., Inc. and Vertex Pharmaceuticals Incorporated have initiated an additional Phase I clinical study with VX-680, a small molecule inhibitor of Aurora kinases.

The two-part, open-label, dose escalation study is designed to evaluate the safety and tolerability of VX-680 when administered over a five-day treatment cycle in patients with haematologic cancers. The study will evaluate VX-680 in patients with relapsed or refractory acute myelogenous leukaemia (AML), myelodysplastic syndrome (MDS), acute lymphocytic leukaemia (ALL) or chronic myelogenous leukaemia (CML) in blast crisis. With the start of this clinical study, Merck and Vertex now have three clinical studies underway with VX-680 in cancer, a company release said here.

The initiation of this clinical study is supported by VX-680’s activity against haematologic cancers in both in vitro and in vivo studies. VX-680 is a potent inhibitor of Aurora kinases and of Flt-3 kinase, which have been implicated in the onset and progression of human leukaemias. VX-680 has demonstrated prolonged survival and induced sustained remission in a model of human AML, and has also shown profound effects in a number of other preclinical cancer models.

“The biologic profile and preclinical studies of VX-680 indicate that this compound has the potential for treating a broad range of human leukaemias by inducing apoptosis in the cells that drive disease,” Stephen H. Friend, executive vice president, Advanced Technology and Oncology at Merck Research Laboratories said adding, “The clinical study announced here is designed to promote rapid clinical assessment of VX-680 in patients with a variety of leukaemic and pre-leukaemic disease states. In addition, access to the leukaemic cells in the blood provides a unique opportunity for understanding the biologic effects and anti-cancer activity of Aurora kinase inhibition on a molecular level.”

In addition to this Phase I study in haematologic cancers announced here, Merck is presently conducting two clinical studies of VX-680 in patients with recurrent or non-responsive solid tumours, or cancers for which standard therapy does not currently exist.

In June 2004, Vertex and Merck entered into a global collaboration to develop and commercialize VX-680. Along with clinical development, Vertex and Merck are conducting a joint research program to characterize VX-680’s activity across a broad range of cancer types and will seek to identify additional drug candidates targeting the Aurora kinases.