Results from CytRx's Phase 2 STAR-1 registration clinical trial for tamibarotene announced

Dec 7 2009

CytRx Corporation (NASDAQ: CYTR), a biopharmaceutical company, today announced favorable preliminary results from its Phase 2 STAR-1 registration clinical trial for tamibarotene in the treatment of acute promyelocytic leukemia (APL) in patients failing other treatments. The results were presented in a poster at the 51st Annual Meeting of the American Society of Hematology (ASH), being held December 5-8, 2009 at the Ernest N. Morial Convention Center in New Orleans, Louisiana.

“These results demonstrate that tamibarotene warrants additional evaluation for the management of APL, which supports our work with key opinion leaders to design a clinical trial to evaluate tamibarotene in combination with other agents as a first-line treatment for this cancer,” stated Steven A. Kriegsman, CytRx President and CEO. “A previously announced dose escalation trial with orally administered tamibarotene combined with arsenic trioxide injection in patients with relapsed APL is currently underway.”

CytRx Chief Medical Officer Daniel Levitt, MD, Ph.D., said, “Some APL patients may choose not to be exposed to all-trans retinoic acid (ATRA) and anthracycline-based chemotherapy – the current first-line treatment for APL. ATRA therapy is associated with several toxicities. The most serious of these is differentiation syndrome, which occurs in up to one-quarter of patients treated with ATRA and is a serious and potentially fatal complication. Additionally, anthracyclines, which are among the most effective anticancer treatments, can cause heart damage, considerably limiting their usefulness. Results from the STAR-1 trial indicate that tamibarotene was well tolerated, which is consistent with other studies, and it is associated with a relatively low incidence of differentiation syndrome and has shown no effect on heart function.”

The poster presented at the ASH meeting, “A Phase II Study of Oral Tamibarotene in Acute Promyelocytic Leukemia (APL) Patients (Pts) Who Have Received Prior Therapy with ATRA and Arsenic Trioxide (STAR-1),“ reviewed preliminary results from the open-label, non-randomized STAR-1 trial, which has a primary endpoint of determining the rate of durable complete response for tamibarotene therapy when administered as a single agent to adult patients following treatment failure with ATRA and arsenic trioxide. Trial patients were administered 6 mg of tamibarotene daily until they achieved remission or for a maximum of 56 days. Following remission, patients could continue tamibarotene treatment at the same dose for three four-week cycles on eight week intervals.

The poster included results from eleven patients who had received a median of seven prior therapies. Of these eleven patients, three (27%) achieved a hematologic complete response, and four (36%) a morphologic leukemia-free state.

The previously announced dose escalation study with tamibarotene combined with arsenic trioxide injection in patients with relapsed APL is currently being conducted by Northwestern University under the leadership of Dr. Martin Tallman, Professor of Medicine, and Dr. Jessica Altman, Assistant Professor of Medicine, both at the Northwestern University Feinberg School of Medicine. In this multi-center Phase 1 trial, between 16 and 22 relapsed APL subjects in three dose groups will be treated with two to three six-week cycles of intravenous arsenic trioxide and self-administered oral tamibarotene tablets with two to six weeks between cycles. A total of 10 subjects will be enrolled at the maximum dose for one or two additional cycles of therapy and evaluated for disease remission. The dose for the subsequent Phase 2 trial will be the dose at which at least five of six subjects tolerate the treatment or the maximum dose used in this trial.