CytRx Corporation Overview
CytRx Corporation (NASDAQ: CYTR), located in Los Angeles, California, is a biopharmaceutical research and development company specializing in oncology. The CytRx oncology pipeline is focused on the clinical development of aldoxorubicin (formerly known as INNO-206), its improved version of the widely used chemotherapeutic agent doxorubicin. CytRx has initiated an international Phase 2b clinical trial as a treatment for soft tissue sarcomas, has completed its Phase 1b/2 clinical trial primarily in the same indication, and has initiated a Phase 1b pharmacokinetics clinical trial in patients with metastatic solid tumors and a Phase 1b study of aldoxorubicin in combination with doxorubicin in patients with advanced solid tumors. The Company is initiating a Phase 3 pivotal trial under a special protocol assessment (SPA) with aldoxorubicin as a therapy for patients with soft tissue sarcomas whose tumors have progressed following treatment with chemotherapy. CytRx is expanding its pipeline of oncology candidates based on a novel linker platform technology that can be utilized with multiple chemotherapeutic agents and could allow for greater concentration of drug at tumor sites. The Company also has rights to two additional drug candidates, tamibarotene and bafetinib. The Company completed its evaluation of bafetinib in the ENABLE Phase 2 clinical trial in high-risk B-cell chronic lymphocytic leukemia (B-CLL), and plans to seek a partner for further development of bafetinib, and is evaluating further development of tamibarotene.
The CytRx Drug Development Portfolio
Aldoxorubicin (formerly INNO-206) is a novel conjugate of the commonly prescribed chemotherapeutic agent doxorubicin that binds covalently to albumin, the most abundant protein in blood plasma, and is circulated throughout the body. Doxorubicin is a standard chemotherapeutic treatment for a variety of cancers and is used either alone or in combination with other chemotherapy agents. Aldoxorubicin is designed with a linker that releases doxorubicin in the low pH environment of tumors, concentrating the chemotherapeutic agent where it preferentially damages the tumor while minimizing the effect on healthy tissues. This conjugate formulation has the potential to safely deliver greater amounts of doxorubicin directly to the tumor compared with standard doxorubicin treatment, which could lead to improved efficacy. CytRx holds the exclusive worldwide rights to aldoxorubicin.
In a Phase 1 clinical trial, aldoxorubicin was administered in doses at up to six times the standard dosing of doxorubicin without an increase in observed side effects over those historically seen with doxorubicin. Animal studies conducted by aldoxorubicin inventor Dr. Felix Kratz, Department of Medical Oncology, Clinical Research, at the Tumor Biology Center in Freiburg, Germany, demonstrated statistically significant results in breast, ovarian, pancreatic and small cell lung cancers. Results of these studies were published in the peer-reviewed journal Investigational New Drugs.
CytRx completed a Phase 1b/2 clinical trial with aldoxorubicin in patients with advanced solid tumors and presented favorable data at the ASCO conference in Chicago, Illinois in June. CytRx also has initiated a Phase 2b international clinical trial in patients with soft tissue sarcomas, and recently initiated a Phase 2 trial for advanced pancreatic ductual adenocarcinomas.
In the Phase 1b/2 clinical trial, clinical benefit (defined as partial response and stable disease of more than four months following up to eight cycles of treatment) with aldoxorubicin at the maximum tolerated dose was shown in 10 of 13 (76.9%) evaluable patients with relapsed or refractory soft tissue sarcoma.
In addition, best response for the 13 evaluable soft tissue sarcoma trial subjects included the following: Five (38.5%) achieved partial response, as defined as tumor shrinkage of more than 30%; Seven (53.8%) showed prolonged stable disease (defined as tumor shrinkage <30% from baseline or tumor growth <20% from the nadir); Eight (61.5%) had tumor shrinkage; and five of eight patients (62.5%) who demonstrated either partial responses or prolonged stable disease after treatment with aldoxorubicin had been previously treated with doxorubicin and had failed to respond.
There were no observed cardiac toxicities and no drug-related patient deaths. The most common adverse event, neutropenia, also observed with doxorubicin treatment, resolved prior to the start of the next treatment.
Median estimated progression-free survival for advanced soft tissue sarcoma patients in the trial was 6.4 months with a range of 1.0 to more than 10.7 months. This compares favorably with the historical median progression-free survival for this patient population of approximately 3 months.
In December 2011, CytRx initiated its international Phase 2b clinical trial to evaluate the preliminary efficacy and safety of aldoxorubicin as a first-line treatment in patients with soft tissue sarcoma who are ineligible for surgery. The Phase 2b clinical trial will provide the first direct clinical trial comparison of aldoxorubicin with native doxorubicin, which is dose-limited due to toxicity, as a first-line therapy.
Aldoxorubicin has been granted orphan drug designation by the Office of Orphan Product Development of the U.S. Food and Drug Administration (FDA) for the treatment of patients with soft tissue sarcomas and pancreatic cancer.
Tamibarotene (formerly known as TM-411, TOS-80T, Am-80, and INNO-507) is an orally available, rationally designed, synthetic retinoid compound which originally 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. CytRx holds the North American and European rights to tamibarotene as a treatment for Non-small-cell lung cancer and APL, among other indications.