CytRx's New Aldoxorubicin Data Demonstrates Significant Advantages over Doxorubicin

CytRx Corporation (NASDAQ:CYTR), a biopharmaceutical research and development company specializing in oncology, today announced compelling preliminary data from its global Phase 2b soft tissue sarcoma trial indicating that patients treated with aldoxorubicin had a significantly higher OVERALL RESPONSE RATE (ORR) of 22% as compared to those administered the widely used chemotherapeutic agent doxorubicin with an ORR of 0%.

Additionally, aldoxorubicin compared with doxorubicin produced statistically significant improvement in survival rates in animals with a human model of glioblastoma (brain tumor), and showed an improved and narrow distribution of aldoxorubicin within the human body in a pharmacokinetics trial. Results from the glioblastoma trial and pharmacokinetics trial were discussed in poster presentations at the 2013 European Cancer Congress (ECCO/ESMO/ESTRO) being held in Amsterdam, Netherlands.

“We are compiling an ever-increasing portfolio of impressive human and pre-clinical data that aldoxorubicin could have an essential role in the treatment of patients with a wide range of cancers,” said CytRx President and CEO Steven A. Kriegsman. “This collective body of data gives us tremendous hope that we will be able to make an important difference in the lives of cancer patients worldwide. This data also supports our belief in the potential benefit of our linker technology platform to one day form the basis of a multi-billion dollar revenue oncology franchise with drugs to treat a wide range of cancers.

“Given the promising prospects for aldoxorubicin, we are aggressively moving forward with its clinical development,” he added. “We recently received acceptance from the U.S. Food and Drug Administration (FDA) for a protocol to conduct a Phase 2 clinical trial with aldoxorubicin in glioblastoma, a very difficult-to-treat and deadly cancer, and also plan to conduct a Phase 2 clinical trial in HIV-related Kaposi’s sarcoma.”

Increased Responses Show OVERALL RESPONSE RATE of 22% in Global Phase 2b Trial in Advanced Soft Tissue Sarcoma

Preliminary data from the Phase 2b clinical trial directly comparing aldoxorubicin with doxorubicin as a first-line treatment for patients with metastatic, locally advanced or unresectable soft tissue sarcomas showed that aldoxorubicin-treated patients demonstrated a significantly greater percentage of overall responses compared with those treated with doxorubicin, the current standard-of-care for advanced, metastatic soft tissue sarcoma. This was based on a blinded reading of tumor scans by an independent radiology review. In this trial, aldoxorubicin was safely delivered at 3.5 times the dose level of doxorubicin in the comparator arm. The overall response data, which were reviewed on a blinded basis by independent radiologists, are as follows:

Responses were evaluated using the RECIST 1.1 criteria. Partial responses are defined as at least a 30% shrinkage in the sum of the longest diameters of target tumors with no increase in non-target tumors or development of new tumors. Stable disease is defined as less than a 20% increase in the longest diameter of target tumors with no increase in non-target tumors or development of new tumors.

“The magnitude of the clinical response difference supports our belief that aldoxorubicin could fill an important medical need in patients with advanced soft tissue sarcoma,” said Executive Vice President and Chief Medical Officer Daniel Levitt, M.D., Ph.D. “Although preliminary, we are certainly optimistic about aldoxorubicin’s prospects in soft tissue sarcoma based on the favorable results from our earlier second-line Phase 1b/2 clinical trial in patients who had failed other therapies and these preliminary overall response results as a first-line treatment announced today. The study is ongoing and many of the patients with tumor responses and stable disease are still receiving treatment.” The Company expects to report top-line data for the global Phase 2b clinical trial in December 2013.

Significantly Increased Survival with Excellent Safety Profile in Glioblastoma Model

CytRx announced additional data from a trial in immunodeficient mice transplanted with human glioblastoma cells in their brain that showed those animals treated with aldoxorubicin had a median survival rate of more than 63 days, compared with approximately 25 days for animals treated with doxorubicin or saline.

“We saw clear evidence of drug concentration inside tumors growing in the brain and significant tumor regression in aldoxorubicin-treated animals, where doxorubicin did not appear to enter the tumor to any significant degree and showed virtually no efficacy in the treatment of these brain tumors,” said Om Prakash, Ph.D., the study’s principal investigator and poster presenter at ESMO. “Aldoxorubicin significantly reduced the number of dividing cells within the brain tumors in this trial and showed a statistically relevant increased expression of apoptosis or cell death markers. The combined results of this trial are significant as glioblastoma is the most common and aggressive of the adult brain tumors with a median survival of 12-14 months despite aggressive treatment.” Dr. Prakash is Research Professor of Medicine, Stanley S. Scott Cancer Center, Louisiana State University (LSU) Health Sciences Center, New Orleans.

FDA Agreement for Phase 2 Clinical Trial in Glioblastoma

“We have reached an agreement with the FDA to enroll up to 28 patients in a Phase 2 clinical trial to evaluate the preliminary efficacy and safety of aldoxorubicin in patients with unresectable glioblastoma whose tumors have progressed following prior treatment with surgery, radiation and with the drug temozolomide. I am pleased to announce that the John Wayne Cancer Center in Santa Monica, Calif.; City of Hope in Duarte, Calif.; and the LSU Cancer Center in New Orleans have agreed to participate in this trial,” stated Dr. Levitt. The trial is set to commence this year with preliminary results expected in the third quarter of 2014. “The strong survival, tumor regression and safety evidence from this study provides more than sufficient rationale to move into clinical development of aldoxorubicin for the treatment of patients suffering from this devastating cancer,” Dr. Levitt added.

Phase 2 Clinical Trial in AIDS-related Kaposi’s Sarcoma

CytRx announced plans to initiate a Phase 2 clinical trial in 2013 evaluating the preliminary efficacy of aldoxorubicin in patients with AIDS-related Kaposi’s sarcoma, a common HIV-associated tumor. The current standard-of-care for severe dermatological and systemic Kaposi’s sarcoma is liposomal doxorubicin (Doxil®); however, a significant proportion of patients exhibit minimal to no clinical response to this agent and the drug’s toxicity often prevents continued therapy. The Phase 2 trial will enroll up to 30 patients and will be conducted at the LSU Health Science Center in New Orleans.

“The key to this trial is that Kaposi’s sarcoma usually manifests as skin lesions. We have the opportunity to biopsy these lesions as the trial progresses and to collect important information about the accumulation of aldoxorubicin at the tumor site,” said Dr. Levitt.

Better, Safer Distribution of Aldoxorubicin in Cancer Patients

CytRx announced in its poster presentation at ESMO that additional data from a Phase 1b clinical trial at the Cedars Sinai Medical Center in Beverly Hills, Calif., evaluating the pharmacokinetics and safety of aldoxorubicin in patients with metastatic solid tumors who have either relapsed or not responded to treatment with standard therapies clearly demonstrate that aldoxorubicin has circulating half-life of approximately 20-24 hours with narrow volume of distribution to healthy tissue and slow clearance from the circulation. Doxorubicin has a significantly shorter half-life and a much wider distribution in normal, healthy tissues in cancer patients than aldoxorubicin. In this study, treatment with aldoxorubicin has extended past 13 cycles (a cycle is 21 days).

“We found that only trace amounts of either free doxorubicin or its major metabolite, doxorubicinol, were detectable in the blood stream even over multiple cycles of administration,” said Dr. Levitt. “The long circulating half-life, slow clearance and narrower volume of distribution of aldoxorubicin provide insights into its ability to safely deliver higher levels of agent to tumors and not normal, healthy tissues compared with doxorubicin.”

About Aldoxorubicin

The widely used chemotherapeutic agent doxorubicin is delivered systemically and is highly toxic, which limits its dose to a level below its maximum therapeutic benefit. It is associated with many side effects–especially the potential for damage to the heart muscle at cumulative doses greater than 500 mg/m². Aldoxorubicin combines doxorubicin with a novel single-molecule linker that binds directly and specifically to circulating albumin, the most plentiful protein in the bloodstream. Protein-hungry tumors concentrate albumin thus increasing the delivery of the linker molecule with the attached doxorubicin to tumor sites. In the acidic environment of the tumor, but not the neutral environment of healthy tissues, doxorubicin is released. This allows for greater doses of doxorubicin to be administered while reducing its toxic side effects. In studies thus far there has been no evidence of clinically significant effects of aldoxorubicin on the heart muscle, even at cumulative doses of drug well over 2 grams/m².

About CytRx Corporation

CytRx Corporation 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 is conducting a global Phase 2b clinical trial with aldoxorubicin as a treatment for soft tissue sarcomas, has completed its Phase 1b/2 clinical trial primarily in the same indication and a Phase 1b study of aldoxorubicin in combination with doxorubicin in patients with advanced solid tumors, and has completed a Phase 1b pharmacokinetics clinical trial in patients with metastatic solid tumors. The Company plans to initiate a Phase 3 global 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 also is initiating Phase 2 clinical trials with aldoxorubicin in patients with late-stage glioblastoma (brain cancer) and Kaposi’s sarcoma. 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. CytRx completed its evaluation of bafetinib in the ENABLE Phase 2 clinical trial in high-risk B-cell chronic lymphocytic leukemia (B-CLL), plans to seek a partner for further development of bafetinib, and is evaluating further development of tamibarotene. For more information about CytRx Corporation, visit www.cytrx.com.

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 outcome, timing and results of CytRx's clinical trials, the risk that any future human testing of aldoxorubicin, including the conclusion of the Phase 2b clinical testing of aldoxorubicin as a first-line treatment in patients with metastatic, locally advanced or unresectable soft tissue sarcomas who have not been previously treated with any chemotherapy, might not produce objective response results similar to the preliminary data described in this press release, or might not correlate with the trial’s primary endpoint of progression-free survival, risks related to CytRx's ability to manufacture its drug candidates in a timely fashion, cost-effectively or in commercial quantities in compliance with stringent regulatory requirements, risks related to CytRx's need for additional capital or strategic partnerships to fund its ongoing working capital needs and development efforts, including the Phase 3 clinical development of aldoxorubicin, 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.