- San Francisco, CA
- press release
Cytokinetics, Incorporated announced today that five abstracts summarizing data from clinical trials conducted by GlaxoSmithKline (GSK) or the National Cancer Institute (NCI) evaluating ispinesib (SB-715992) or SB- 743921 will be presented at the 2006 Annual Meeting of the American Society of Clinical Oncology (ASCO) in Atlanta, Georgia.
Ispinesib and SB-743921 are both novel, chemically distinct, small molecule inhibitors of kinesin spindle protein (KSP), a mitotic kinesin essential for proper cell division. Both drug candidates have arisen from a broad strategic collaboration between Cytokinetics and GSK to discover, develop and commercialize novel small molecule therapeutics targeting human mitotic kinesins for applications in the treatment of cancer and other diseases.
A Phase II Study of SB-715992 (Ispinesib) in Patients with Recurrent and/or Metastatic Head and Neck Squamous Cell Carcinoma (RMHNSC). Abstract will be published in the ASCO 2006 Annual Meeting Proceedings.
Ispinesib is a novel small molecule inhibitor of Kinesin Spindle Protein (KSP), a mitotic kinesin protein essential for proper cell division. Ispinesib is the first drug candidate in clinical development that has arisen from a broad strategic collaboration between Cytokinetics and GSK to discover, develop and commercialize novel small molecule therapeutics targeting human mitotic kinesins for applications in the treatment of cancer and other diseases. GSK is conducting a broad clinical trials program for ispinesib designed to study this drug candidate in multiple tumor types, combination regimens and dosing schedules.
GSK is currently evaluating ispinesib in two Phase II clinical trials being conducted in patients with each of ovarian and breast cancers and two Phase Ib clinical trials designed to evaluate ispinesib in combination with each of carboplatin and capecitabine. Interim data from the ongoing breast cancer clinical trial and data from the platinum-refractory and the platinum-sensitive treatment arms of the non-small cell lung cancer clinical trial were announced recently.
In the Phase II clinical trial enrolling patients with advanced breast cancer, the best overall responses observed with ispinesib administered as monotherapy have been partial responses in 3 of 33 evaluable patients to date. These 3 patients had maximum decrease in tumor size ranging from 46% to 68% with the duration of response ranging from 7.1 weeks to 13.4 weeks. The overall response rate in this clinical trial for all 33 evaluable patients was 9% with an overall median time to progression of 5.7 weeks.
In the platinum-refractory treatment arm of a Phase II clinical trial enrolling patients with non-small cell lung cancer, the best overall response observed with ispinesib administered as monotherapy was disease stabilization in 25% of evaluable patients (N=20) with a median time to progression (TTP) of 12 weeks (overall median TTP was 6 weeks). In the platinum-sensitive treatment arm of this Phase II clinical trial, the best overall response observed with ispinesib administered as monotherapy was disease stabilization in 50% of evaluable patients (N=20) with a median TTP of 17 weeks (overall median TTP was 6 weeks).
For both clinical trials, the adverse events were manageable, predictable, and consistent with the Phase I experience. The most common adverse event was Grade 4 neutropenia. In addition to the ongoing studies being conducted by GSK, the National Cancer Institute (NCI) is sponsoring five other Phase II clinical trials evaluating ispinesib in other tumor types, including melanoma, head and neck, hepatocellular, colorectal and prostate cancers. In addition, the NCI plans to conduct an additional Phase II clinical trial in patients with renal cell carcinoma. The NCI is also conducting two other Phase I clinical trials evaluating an alternative schedule of ispinesib in leukemia and advanced solid tum