Spectrum Pharmaceuticals to present data on Ortataxel in breast cancer at major oncology meeting

May 19 2008

Spectrum Pharmaceuticals, Inc., will present Phase 2 data on ortataxel at the 44th American Society of Clinical Oncology (ASCO) Annual Meeting being held May 30 to June 3, 2008 at the McCormick Place Convention Center in Chicago, Illinois.

Ortataxel is a third-generation orally bioavailable taxane, that has activity in tumor models resistant to paclitaxel and docetaxel. A study indicating activity in taxane-resistant non-small cell lung cancer had been previously reported. Results of the Phase 2 study in resistant breast cancer patients will be presented in a poster session on Monday, June 2, 2008. The abstract, entitled "Phase 2 Study of Ortataxel in Taxane-Resistant Breast Cancer" is available now on the ASCO website, www.asco.org.

"Ortataxel has demonstrated activity in taxane-refractory tumors in Phase 2 trials, and we believe that with further clinical development, it could be an effective treatment option within the multi-billion dollar taxane market," said Rajesh C. Shrotriya, M.D., Chairman, President and Chief Executive Officer of Spectrum Pharmaceuticals, Inc. "We plan to initiate a Phase 2 trial in relapsed lung cancer in the second half of 2008."

This single-arm Phase 2 study was performed in 23 centers, in patients with advanced or metastatic breast cancer with resistant disease (defined as disease progression within 6 months of the start of prior treatment with another taxane). Patients received ortataxel, 75 mg/m² as a 1-hour i.v. infusion every 3 weeks. Primary endpoint was objective tumor response, complete (CR) or partial (PR).

Of the 85 patients accrued, 82 were treated and 76 were evaluable for response. Nearly half the patients had an impaired general condition (performance status of 1 or 2), 31% had received more than 4 distinct chemotherapy regimens and 62% had been previously irradiated.

There were 6 PRs (7% of all treated; 95% confidence interval 2.5-12%), with a median response duration of 7 months (range, 4-9 months). Only 2 of the 6 responders had a long-lasting prior response to a taxane. Additionally, 31 patients (38%) experienced disease stabilization (SD) lasting 1.5 - 11+ months. Thus the overall disease control rate (PR + SD) was 45%.

Adverse effects of any grade were seen in 80 patients, including 2 deaths from liver failure. Neutropenia was present in 74%. Peripheral neuropathy was severe in 5%. Fatigue and malaise were also significant. Hematologic side effects were graded as severe in 57% while non-hematologic severe effects were noted in 9% of patients.

Ortataxel retains encouraging activity and clinical benefit in breast cancer patients who are resistant to paclitaxel or docetaxel combinations. Its toxicity, comparable in type to these two other taxanes, was tolerable in this patient population, who had received heavy prior treatment.

Ortataxel (14-beta-hydroxydeacetylbaccatin) belongs to a new generation of taxanes with the potential to be active in tumors resistant to Bristol-Myers Squibb's Taxol® (paclitaxel) and Sanofi-Aventis' Taxotere® (docetaxel). The bioavailability of ortataxel following oral administration has been confirmed in previous studies. Phase 2 studies in taxane-refractory solid tumors have indicated a good level of activity. The safety profile of ortataxel so far has been comparable to that of paclitaxel and docetaxel.