Cell Therapeutics Announces Interim Results From Phase 2 Tosedostat Trial

(RTTNews) - Cell Therapeutics, Inc. (CTIC) announced promising interim results from an investigator-initiated Phase 2 clinical trial of tosedostat in combination with cytarabine or decitabine in newly diagnosed older patients with acute myeloid leukemia or AML or high-risk myelodysplastic syndrome or MDS.

The company noted that the interim results of Tosedostat in combination with chemotherapy or hypomethylating agents in first-line demonstrated 54 percent complete response rate and 12-month median survival.

Tosedostat is a first-in-class selective inhibitor of aminopeptidases, which are required by tumor cells to provide amino acids necessary for growth and tumor cell survival. Tosedostat is administered orally and has been previously shown to induce complete remissions as monotherapy in relapsed or refractory AML.

The company said that researchers presented the findings from this combination study today for the first time at the 55th American Society of Hematology or ASH Annual Meeting and Exposition held December 7-10 in New Orleans, La.

According to the company, the Phase 2 trial was designed to test the efficacy of tosedostat in combination with low intensity therapy for older patients with previously untreated AML or high-risk MDS not considered candidates for standard intensive therapy. This presentation reported on the results of 26 patients (median age was 69) enrolled in the first dose cohort. Patients were randomized to treatment with tosedostat in combination with either cytarabine or decitabine.

Fourteen out of 26 (54 percent) patients in this cohort had either a complete response (CR; n=10, 39 percent) or complete response with incomplete blood count recovery (CRi; n=4, 15 percent). The percentage of complete responses was comparable between arms. Seven (50 percent) of the 14 CR/CRi were achieved in patients with poor-risk cytogenetic features. Importantly, 10 of the 26 patients subsequently went on to receive hematopoietic stem cell transplant. The study achieved its primary objective with 21 (82 percent) patients alive at four months. Median overall survival was encouraging at approximately 12 months for both study arms.

Tosedostat combination therapy was well tolerated and predominantly administered as an outpatient therapy. The primary side effects of the combination therapy, the majority of which were associated with the cytarabine arm, included febrile neutropenia (50 percent), pulmonary infections (31 percent) and sepsis (19 percent). Clinically significant non-hematological toxicities were uncommon and predominantly low grade.