O.k., a bit old now, but it doesn't seem to have been posted before.
Hayward, CA – June 5, 2006 – Kosan Biosciences Incorporated (NASDAQ: KOSN) presented results from three Phase I trials of its two heat shock protein 90 (Hsp90) inhibitors, KOS-953 and KOS-1022, at the 42nd Annual Meeting of the American Society of Clinical Oncology (ASCO) in Atlanta, Georgia. Results from these trials demonstrated encouraging clinical activity and safety profiles for both compounds.
“Kosan’s Hsp90 inhibitors have each shown the ability to enhance anti-tumor activity in combination with standard chemotherapies based on their unique mechanism of action,” said Robert G. Johnson, Jr., M.D., Ph.D., Kosan’s Chief Executive Officer. “We are excited by KOS-953’s demonstrated clinical activity in patients with resistant HER2-positive breast cancer and relapsed refractory multiple myeloma. These data suggest that our compounds can re-induce anti-tumor activity after relapse or synergize initial activity of existing cancer therapies. We are also encouraged by the promising activity of KOS-1022, our second-generation Hsp90 inhibitor. We expect to see a significant maturation of our cancer clinical programs in the coming months.”...
KOS-953: Interim Data from Phase I/II Combination Trial with Trastuzumab (Herceptin®)
KOS-953 is an Hsp90 inhibitor that has demonstrated the potential to disrupt the activity of multiple oncogenes and cell signaling pathways implicated in tumor growth, including HER2, a key pathway in breast cancer. In the Phase I portion of the trial, KOS-953 was administered in combination with trastuzumab (Herceptin) to 25 patients with refractory solid tumors, 17 of whom had HER2-positive metastatic breast cancer. The dosing schedule was a weekly intravenous infusion (dose escalating from 225-450 mg/m2). Out of the 17 patients with HER2-positive metastatic breast cancer:
• One patient experienced a partial response (59 percent decrease in lung metastases).
• Four patients experienced tumor shrinkage (20 percent or greater), including two patients with complete responses by World Health Organization (WHO) criteria.
• All patients who experienced tumor regression had radiographically documented tumor progression on a Herceptin regimen immediately prior to entering the study.
In addition, four patients in the Phase I portion of the study experienced stable disease (four months or longer).
Adverse events were generally mild. The only dose-limiting toxicity at the highest dose of 450 mg/m2 was a dose delay in a patient with Grade 2 thrombocytopenia. There was no drug-drug interaction between KOS-953 and Herceptin. Induction of Hsp70 (an indicator of Hsp90 inhibition) was observed at all dose levels.
The data were presented in an oral session on Saturday, June 3, by Shanu Modi, M.D., of Memorial Sloan-Kettering Cancer Center.
“We are excited by the demonstration of anti-tumor activity of KOS-953 in metastatic breast cancer patients whose disease is resistant to treatment with Herceptin,” said Dr. Modi. “These encouraging results indicate that use of an Hsp90 inhibitor in combination with Herceptin may have the potential to reinstitute or extend the efficacy of Herceptin, without adding significant toxicity, and could represent a meaningful benefit to breast cancer patients.”
The Phase II portion of this KOS-953 clinical trial was initiated in early 2006 with a dosing regimen of 450 mg/m2 weekly along with the standard dose of Herceptin to patients with HER2-positive metastatic breast cancer. Preliminary results presented by Dr. Modi indicated that out of the first five patients enrolled in the Phase II portion, there was one unconfirmed partial response and one unconfirmed minor response. Both patients are still on study. Kosan expects to announce further results from this Phase II clinical trial near the end of 2006.'
Linear Mode
