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CytRx Announces Positive Phase 2 Results For Tamibarotene in the Treatment of Relapsed Acute Promyelocytic Leukemia

- Data Presented at the 2009 ASH Conference -


LOS ANGELES--(BUSINESS WIRE)--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.


About Tamibarotene


Tamibarotene is an orally available, rationally designed, synthetic retinoid compound which was designed to potentially avoid toxic side effects by binding to its molecular target more selectively than all trans-retinoic acid (ATRA), the current first line treatment for APL. There are currently no approved third-line treatment options for refractory APL subjects, an annual market that CytRx estimates at approximately $20 million in the U.S. and $25 million in Europe. The estimated annual market potential in the U.S. and Europe for an expanded label for tamibarotene that includes refractory, maintenance and front-line therapy is up to $150 million. A Special Protocol Assessment (SPA) is in place with the U.S. Food and Drug Administration (FDA) for a Phase 2 STAR-1 trial. The STAR-1 trial is ongoing and currently includes six clinical sites in the U.S.


The FDA has granted Orphan Drug Designation for APL and Fast Track Designation for the use of tamibarotene in patients with relapsed or refractory APL following treatment with ATRA and arsenic trioxide. In addition, tamibarotene has been granted orphan medicinal product status by the European Medicines Agency for the treatment of APL. The efficacy of tamibarotene was demonstrated in two Phase 2 studies conducted in Japan in a total of 63 Japanese subjects with APL. The overall complete response rate in these subjects was 60%. In subjects experiencing their first relapse, the overall complete response rate was 81%. Tamibarotene is currently approved for relapsed or refractory treatment of APL in Japan.


Tamibarotene also has demonstrated statistically significant anti-tumor activity in an animal trial for multiple myeloma, an incurable malignant tumor of the plasma cells of bone marrow.


CytRx holds the North American and European rights to tamibarotene as a treatment for APL. CytRx also has the right to develop tamibarotene as a treatment for multiple myeloma in Europe, and has the option to expand its license for the use of tamibarotene for multiple myeloma and certain other oncology applications in the U.S.


About Acute Promyelocytic Leukemia (APL)


Acute promyelocytic leukemia (APL) is a subtype of acute myeloid leukemia (AML) characterized by the balanced chromosomal translocation, (15;17) that results in the creation of the fusion gene product PML/RAR-alpha, which is critical in the pathogenesis of the disease. APL occurs in 10% to 15% of adults with AML. In the U.S. approximately 1,500 cases of APL are diagnosed each year. The disease is clinically notable for life-threatening coagulopathy, which has historically been the major cause of death.


About CytRx Corporation


CytRx Corporation is a biopharmaceutical research and development company engaged in the development of high-value human therapeutics. The CytRx drug development pipeline includes programs in clinical development for cancer indications, including tamibarotene in a clinical trial for the treatment of acute promyelocytic leukemia (APL). CytRx recently announced plans to initiate Phase 2 trials with its oncology candidate INNO-206 as a treatment for gastric cancer and soft tissue sarcomas. In addition, CytRx is developing two drug candidates based on its industry-leading molecular chaperone technology, which aims to repair or degrade misfolded proteins associated with disease. CytRx also maintains a 36% equity interest in publicly traded RXi Pharmaceuticals, Inc. (NASDAQ:RXII). For more information on the Company, visit


Forward-Looking Statements


This press release contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended. Such statements involve risks and uncertainties that could cause actual events or results to differ materially from the events or results described in the forward-looking statements, including risks relating to the timing, outcome or results of any clinical testing of tamibarotene as a treatment for APL or as a treatment for multiple myeloma, risks relating to CytRx's ability to obtain regulatory approval for clinical testing of tamibarotene as a first-line treatment for APL, the scope of clinical testing that may be required by regulatory authorities, risks related to CytRx's ability to manufacture tamibarotene in commercial quantities in compliance with stringent regulatory requirements, risks related to CytRx's ability to enter into partnerships or other transactions to advance the clinical development of its portfolio of drug candidates, or commercialize any of CytRx's current drug candidates or initiate commercial operations through the acquisition of any newly identified drug candidates, risks related to CytRx's need for additional capital or strategic partnerships to fund its ongoing working capital needs and development efforts, risks related to the future market value of CytRx's investment in RXi and the liquidity of that investment, and the risks and uncertainties described in the most recent annual and quarterly reports filed by CytRx with the Securities and Exchange Commission and current reports filed since the date of CytRx's most recent annual report. All forward-looking statements are based upon information available to CytRx on the date the statements are first published. CytRx undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.






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Posted: December 2009