CytRx Corporation (NASDAQ: CYTR), a biopharmaceutical company specializing in oncology, announced that a 44-year-old female patient with advanced acute promyelocytic leukemia (APL) achieved molecular complete remission with no evidence of disease in the blood cells and/or bone marrow following treatment with CytRx's oncology drug candidate tamibarotene. The patient was treated in CytRx's Phase 2 STAR-1 registration trial, which is evaluating the efficacy and safety of orally available tamibarotene as a third-line treatment for APL. The patient report, "Molecular remission in advanced acute promyelocytic leukaemia after treatment with the oral synthetic retinoid Tamibarotene," (Francesco Lo-Coco, et. al.), was published in the July online issue of the peer-reviewed British Journal of Haematology with publication in the print edition expected later this year.

"This event represents a very significant milestone for CytRx and our drug candidate tamibarotene. Tamibarotene has saved a life and nothing can compare with that," said CytRx President and CEO Steven A. Kriegsman. "These important results indicate that tamibarotene warrants further evaluation as a third-line treatment and in combination as a first-line treatment for APL. We are also considering developing tamibarotene for other cancers as well.

"Previously published reports indicate that tamibarotene is 10-times more potent and may be better tolerated than all trans retinoic acid (ATRA). We believe that the combination of tamibarotene and arsenic trioxide (ATO) could produce a complete response rate similar to the ATRA and ATO combination with fewer toxicities such as APL differentiation syndrome. We currently are conducting a dose escalation trial combining tamibarotene with ATO as an important step in our ultimate goal of evaluating tamibarotene as a first-line treatment for APL," he added.

CytRx Chief Medical Officer Daniel Levitt, M.D., Ph.D., stated, "This demonstrates that orally administered tamibarotene is active in APL patients relapsing after treatment with ATRA, anthracyclines, and ATO, the current first and second-line treatments, and a bone marrow transplant." In addition to maintaining a complete remission six months following the last dose, tamibarotene was also well tolerated. This patient reportedly had a severe toxic reaction called APL differentiation syndrome when given ATRA. However, when tamibarotene was administered, the patient achieved a molecular complete remission without these side effects."

The APL patient profiled in the peer-reviewed British Journal of Haematology article was initially treated simultaneously with ATRA and chemotherapy. Following treatment she achieved molecular complete remission, although she developed severe APL differentiation syndrome. During the subsequent two years, she received maintenance therapy and then suffered an APL relapse. She was treated with a combination therapy of ATRA and ATO, and again achieved molecular complete remission. She then underwent a bone marrow transplant, at which time molecular complete remission was confirmed. However, her APL relapsed again. The patient was then enrolled in CytRx's STAR-1 registration trial and treated with tamibarotene for 56 days at the Department of Biopathology at the University of Rome 'Tor Vergata'. A molecular complete remission in the bone marrow was documented at the end of the treatment period and again six months following the last treatment with tamibarotene.

About Tamibarotene

The ongoing Phase 2 STAR-1 registration trial, which is evaluating the efficacy and safety of tamibarotene as a third-line treatment for APL, is being conducted under a Special Protocol Assessment (SPA). In June 2009 CytRx reported that, of the 11 patients enrolled in the STAR-1 trial at that time, three (27%) achieved a hematologic complete response, and four (36%) a morphologic leukemia-free state. In December 2009, favorable preliminary results from the STAR-1 registration trial were presented at the Annual Meeting of the American Society of Hematology (ASH).

The U.S. Food and Drug Administration (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 ATO. In addition, tamibarotene has been granted orphan medicinal product status by the European Medicines Agency for the treatment of APL. The efficacy of orally administered 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%.

A dose escalation study with tamibarotene combined with ATO in patients with relapsed APL is currently being conducted by Northwestern University under the leadership of Dr. Jessica Altman, Assistant Professor of Medicine, 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 ATO 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. CytRx plans to conduct a subsequent Phase 2 trial with tamibarotene at the dose at which at least five of six subjects tolerate the treatment or the maximum dose used in this trial.

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 retains an option to expand its licenses for the use of tamibarotene in other fields in oncology, including multiple myeloma, myelodysplastic syndrome and certain solid tumors in the U.S., and multiple myeloma, myelodysplastic syndromes and solid tumors other than hepatocellular carcinoma in Europe.

About Acute Promyelocytic Leukemia (APL)

APL is diagnosed in approximately 1,500 new patients in the U.S. annually. It is a subtype of acute myelogenous leukemia, a cancer of the blood and bone marrow. In APL, an abnormal accumulation of immature granulocytes called promyelocytes in the bone marrow results in a reduction in the production of normal red blood cells and platelets, resulting in anemia and thrombocytopenia. Either leukopenia (low white cell count) or leukocytosis (high white cell count) may be observed in the peripheral blood. Symptoms include fatigue, weakness, shortness of breath from anemia, easy bruising and bleeding from thrombocytopenia and coagulopathy, and fever and infection from lack of normal white blood cells.

Source:
CytRx Corporation