Favorable results from CytRx’s INNO-206 Phase 1b/2 trial on soft tissue sarcomas

CytRx Corporation (NASDAQ: CYTR), a biopharmaceutical company specializing in oncology, announces that favorable clinical results from its Phase 1b/2 clinical trial with its tumor-targeting doxorubicin conjugate INNO-206 in patients with advanced solid tumors, primarily soft tissue sarcomas, are being presented today at the American Society of Clinical Oncology (ASCO) conference in Chicago. All patients in the study had either not responded to or relapsed after treatment with between one and three prior chemotherapy regimens.    

Clinical benefit (defined as partial response and stable disease of more than four months following up to eight cycles of treatment) with INNO-206 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
• Five of eight patients (62.5%) who demonstrated either partial responses or prolonged stable disease after treatment with INNO-206 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.

The presentation at ASCO was made by the trial's principal investigator Sant P. Chawla, M.D., F.R.A.C.P., Director of the Sarcoma Oncology Center in Santa Monica, Calif. Dr. Chawla is a world-renowned expert in soft tissue sarcoma treatment who has evaluated most chemotherapies being tested in this indication. The poster, entitled "Phase 1b/2 Study of INNO-206 (EMCH-doxorubicin) in Patients with Soft Tissue Sarcoma," was authored by Dr. Chawla, Victoria S. Chua, Andrew Hendifar, M.D., Doris Quon and Sandeep Nagre of the Sarcoma Oncology Center; Kristen N. Ganjoo, M.D. of Stanford University; Kamalesh Sankhala, M.D. of the University of Texas Health Science Center; and Scott Wieland, Ph.D. and Daniel Levitt, M.D., Ph.D. of CytRx.

"The Phase 1b/2 clinical results are exciting and highly supportive of the continued evaluation of INNO-206 as a first-line therapy in patients with advanced soft tissue sarcomas in CytRx's ongoing international Phase 2b clinical trial," stated Dr. Chawla. "These data are even more impressive given the advanced stage of disease of the trial patients and the fact that these patients had already either not responded to or relapsed after being treated with, on average, two prior therapies. Additionally the lack of cardiac toxicity thus far is significant, as this reduces the potential for cardiac safety issues that are associated with standard doxorubicin and limits its clinical efficacy. I was impressed by the progression-free survival of approximately 6.4 months, which is longer than the 4.4 month PFS seen with pazopanib treatment in a very similar patient population. Pazopanib, commercially known as Votrient, was recently approved by the FDA as a second-line treatment for soft tissue sarcomas."

"These are powerful results in a very sick patient population. In light of the strength of these results and the fact that there are only limited approved therapies for patients with advanced soft tissue sarcomas, we plan to meet with the FDA to discuss a Phase 3 pivotal trial design with INNO-206 as a third-line therapy in soft tissue sarcoma patients," said CytRx President and CEO Steven A. Kriegsman. "We have consulted with key thought leaders in the field of soft tissue sarcomas and are preparing a draft clinical trial protocol. If we get approval from the FDA to move forward with this trial, we believe it could be the pivotal study necessary to file for FDA marketing approval, allowing us to eliminate years from the traditional regulatory process."

"CytRx holds exclusive worldwide rights to INNO-206, which is based on a proprietary linker technology that offers multiple potential benefits," stated CytRx Chief Medical Officer Dr. Daniel Levitt. "This technology allows the agent to concentrate at tumor sites where the delivery molecule is cleaved and the drug, in this instance doxorubicin, is released. The ability to deliver substantially more of the agent directly to the tumor site could improve effectiveness. Further, the drug attached to the linker is inactive until it is cleaved. This occurs at the tumor site and only in one other organ, the bone marrow. Thus, INNO-206 avoids many of the side effects associated with systemic delivery of doxorubicin itself."

Source: CytRxCorporation