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CytRx's Drug Candidate INNO-206 Produces Statistically Significant Tumor Shrinkage in Animal Model of Small Cell Lung Cancer

Results to Be Published in the Peer-Reviewed Journal Investigational New Drugs


Clinical Development Plans for INNO-206 to Be Announced Next Quarter


LOS ANGELES--(BUSINESS WIRE)--Aug 12, 2009 - CytRx Corporation (NASDAQ:CYTR), a biopharmaceutical research and development company engaged in the development of high-value human therapeutics, today announced that its proprietary drug candidate INNO-206 dramatically inhibited tumor growth in an experimental animal model of small cell lung cancer (SCLC). The results of the trial have been released in electronic form and accepted for publication in the peer-reviewed journal Investigational New Drugs.


CytRx's INNO-206 is a pro-drug derivative of the commonly prescribed chemotherapeutic agent doxorubicin. INNO-206 is designed to reduce adverse events by controlling drug release and preferentially targeting tumors. In a Phase 1 clinical trial, INNO-206 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. In the Phase 1 clinical trial of 35 patients with various cancers treated with INNO-206, three patients showed a partial tumor reduction and 20 patients showed stable disease over the course of the trial. All three of the partial responses occurred at the higher dose ranges of the dose-ranging safety study.


CytRx president and CEO Steven A. Kriegsman stated, “We hold the exclusive worldwide rights to INNO-206, which has demonstrated statistically significant efficacy in animal models of multiple cancer types. INNO-206 epitomizes our corporate strategy of minimizing development risk by focusing on drug candidates that have been tested in humans with very fundamental mechanisms of action that make them potentially efficacious in multiple oncology indications. The ability to inhibit SCLC tumor growth in an animal model is gratifying given the fact that this cancer is particularly devastating. In light of this compelling animal data in SCLC, and previously announced positive data showing INNO-206's potential to treat breast, pancreatic and ovarian cancer, we are designing potential Phase II clinical trials for one or more of those deadly diseases, and expect to announce our plans in the fourth quarter of 2009.”


INNO-206 inventor Dr. Felix Kratz, Department of Medical Oncology, Clinical Research, at the Tumor Biology Center in Freiburg, Germany, directed the animal study in which 10 million human H209 SCLC tumor cells from cell culture were transplanted under the skin of 32 mice, all lacking a normal immune system that would otherwise reject these cells. When the tumors had grown to a palpable size 20 days later, the experimental animals were randomly separated into four treatment groups of eight each. Two groups were treated with two cycles of weekly 8 mg/kg intravenous injections of either doxorubicin or CytRx's INNO-206. Although doxorubicin doses above 8 mg/kg were not tolerable and resulted in animal deaths, INNO-206's lower toxicity allowed the third animal group to be treated more aggressively, with three weekly cycles of 24 mg/kg INNO-206 injections. The fourth group received intravenous injections lacking either drug and served as a control. Tumor growth was monitored continuously throughout the remainder of the 44-day experiment.


Neither doxorubicin nor INNO-206 at two weekly cycles of 8 mg/kg intravenous dosing produced evidence of significant anti-tumor effect, with relative-tumor volumes increasing approximately 20-fold or 16-fold, respectively, 24 days after initiation of therapy, which was comparable to the control. However, the group treated with three weekly cycles of 24 mg/kg intravenous INNO-206, because of its improved tolerability compared to doxorubicin, produced a statistically significant (p<0.05) anti-tumor effect with relative tumor volumes increasing only by a factor of approximately 3.5 at the end of the experiment. In addition to the remarkably improved efficacy of INNO-206 compared to doxorubicin, its toxicity based on body weight loss following three weekly cycles of 24 mg/kg was comparable to that seen with only two weekly cycles of doxorubicin at 8 mg/kg based on body weight loss.


“We were not surprised that doxorubicin did not significantly inhibit tumor growth in this animal model as this broadly prescribed chemotherapeutic agent has not proven effective as an SCLC treatment unless used as part of a multi-drug cocktail,” stated Joseph Rubinfeld PhD, co-founder of Amgen, CytRx Chief Scientific Advisor and world-renown oncologist. “By contrast, higher doses of the more tolerable INNO-206 showed dramatic and statistically significant inhibition of tumor growth even as a single agent in this animal model, apparently because its pro-drug structure allowed for the accumulation of higher levels of the drug specifically targeting the tumor.”


About Small Cell Lung Cancer (SCLC)


Lung cancer is the leading cause of U.S. cancer death in men and women, accounting for more deaths than breast, prostate and colon cancers combined, according to the American Cancer Society. SCLC represents 15% of all lung cancer incidents, with more than 30,000 new SCLC cases diagnosed every year in the U.S. Without treatment, the average survival rate following SCLC diagnosis is only two to four months. According to a 2006 publication (R. Govindan et al, J Clin Oncol 24, 4539-4544) patients with best prognosis SCLC (limited-stage disease) have an 11% five-year survival and those with the worst prognosis SCLC (extensive-stage disease) have a 6% two-year survival rate.


About INNO-206


INNO-206 is a prodrug of the commonly prescribed chemotherapeutic doxorubicin and was designed to reduce adverse events by controlling release and preferentially targeting the tumor. In a Phase 1 study, doses were administered at up to six times the standard dosing of doxorubicin without an increase in observed side effects over those historically seen with doxorubicin.


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 registration study for the treatment of acute promyelocytic leukemia (APL). 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 39% 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 future pre-clinical or clinical testing of INNO-206 as a treatment for small cell lung cancer, the risk that any future human testing of INNO-206 for small cell lung cancer might not produce results similar to those seen in animals, risks related to CytRx's ability to manufacture its drug candidates, including INNO-206, in a timely fashion, cost-effectively or 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, risks related to CytRx's need for additional capital or strategic partnerships to fund its ongoing working capital needs and development efforts, including any future clinical development of INNO-206, 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: August 2009