Synta Presents STA-9090 NSCLC data at the IASLC10th Annual Targeted Therapies of the Treatment of Lung Cancer Meeting

-STA-9090 shows activity against EGFR T790M resistance mutation -
- Simultaneously inhibits MET, a key mechanism of resistance, and EGFR -

LEXINGTON, Mass., Feb 26, 2010 (BUSINESS WIRE) -- Synta Pharmaceuticals Corp. (NASDAQ: SNTA), a biopharmaceutical company focused on discovering, developing, and commercializing small molecule drugs to treat severe medical conditions, today announced that Dr. Geoffrey I. Shapiro of Dana-Farber Cancer Institute, presented preclinical and clinical data on STA-9090, a potent second-generation Hsp90 inhibitor, at IASLC (International Association for the Study of Lung Cancer) 10th Annual Targeted Therapies of the Treatment of Lung Cancer Meeting in Santa Monica, CA.

"Results to date demonstrate that the Hsp90 inhibitor STA-9090 has greater potency compared to first-generation Hsp90 inhibitors, such as 17-AAG, in destabilizing critical oncoproteins and components of their signaling pathways, including EGFR, ERBB2 (HER2), BRAF and MET," said Geoffrey Shapiro, M.D., Ph.D., Dana-Farber, a co-principal investigator on the recently initiated Phase 2 trial for STA-9090 in NSCLC. "In early trials, STA-9090 has shown promising signs of single-agent activity and an acceptable safety profile, without the severe liver and other toxicities observed with the first-generation Hsp90 inhibitors. These preclinical and early clinical results are encouraging and support the ongoing Phase 2 multicenter clinical study of STA-9090 in NSCLC."

The presentation by Dr. Shapiro can be found on the Synta Pharmaceuticals website at http://www.syntapharma.com.

"We are pleased to have STA-9090 presented as a leading Hsp90 inhibitor program in NSCLC at this major international lung cancer meeting" said Vojo Vukovic, M.D., Ph.D., Chief Medical Officer, Synta Pharmaceuticals. "We are particularly encouraged that leading lung cancer investigators have shown a high level of interest in participating in our NSCLC clinical trial with STA-9090."

Synta is currently enrolling patients in a Phase 2 single-arm, open-label, single-agent study of STA-9090 in patients with stage IIIB or IV non-small cell lung cancer, with patient cohorts defined by the genetic profile of their tumors.

About STA-9090

STA-9090 is a potent, synthetic, small-molecule Hsp90 inhibitor, with a chemical structure unrelated to the first-generation, ansamycin family of Hsp90 inhibitors (e.g., 17-AAG or IPI-504). In preclinical studies, STA-9090 has shown potency up to 100 times greater than the first-generation Hsp90 inhibitors as well as activity against a wider range of kinases. In in vitro and in vivo models, STA-9090 has shown potent activity against a wide range of cancer types, including lung, prostate, colon, breast, gastric, pancreatic, melanoma and certain hematologic cancers - as well as potent activity against cancers resistant to imatinib (Gleevec(R)), sunitinib (Sutent(R)), erlotinib (Tarceva(R)), and dasatanib (Sprycel(R)).

Synta is currently conducting Phase 2 trials in non-small cell lung cancer (NSCLC) and gastrointestinal stromal tumors (GIST), two Phase 1/2 clinical trials of STA-9090 in hematologic cancers and two Phase 1 trials of STA-9090 in solid tumor cancers. The most common adverse events observed to date have been fatigue and diarrhea, which were manageable and reversible. Information on clinical trials with STA-9090 can be found at http://www.clinicaltrials.gov.

About the STA-9090 Phase 2 Trial in NSCLC

SyntaPharmaceuticals is currently enrolling patients in aPhase 2 study evaluating the efficacy and safety of STA-9090 in subjects with Stage IIIB or IV non-small cell lung cancer (clinicaltrials.gov: NCT01031225). The trial is currently being conducted at 10 centers in the United States. STA-9090 is administered as an intravenous infusion once weekly for three weeks followed by a one week dose-free interval. The primary endpoint of the trial is progression-free survival.

About Hsp90

Hsp90 is a chaperone protein required for the proper folding and activation of other cellular proteins, particularly kinases. Many of these "client proteins" of Hsp90 - such as AKT, BCR-ABL, BRAF, KIT, MET, EGFR, FLT3, HER2, PDGFRA, VEGFR - have been shown to be critical to cancer cell growth, proliferation, and survival and are the targets of clinically validated cancer drugs. In preclinical studies, inhibiting Hsp90 causes the degradation of multiple client proteins and leads to cancer cell death. Because mutated kinases which no longer respond to treatment with kinase inhibitors remain dependent on Hsp90 for their activity, inhibiting Hsp90 offers the potential for treating cancers that have become resistant to targeted therapies such as kinase inhibitors.

About Synta Pharmaceuticals

Synta Pharmaceuticals Corp. is a biopharmaceutical company focused on discovering, developing, and commercializing small molecule drugs to extend and enhance the lives of patients with severe medical conditions, including cancer and chronic inflammatory diseases. Synta has a unique chemical compound library, an integrated discovery engine, and a diverse pipeline of clinical- and preclinical-stage drug candidates with distinct mechanisms of action and novel chemical structures. All Synta drug candidates were invented by Synta scientists using our compound library and discovery capabilities. For more information, please visit http://www.syntapharma.com.

Safe Harbor Statement

This media release may contain forward-looking statements about Synta Pharmaceuticals Corp. Such forward-looking statements can be identified by the use of forward-looking terminology such as "will", "would", "should", "expects", "anticipates", "intends", "plans", "believes", "may", "estimates", "predicts", "projects", or similar expressions intended to identify forward-looking statements. Such statements, including statements relating to the timing, developments and progress of our clinical and preclinical programs, reflect our current views with respect to future events and are based on assumptions and subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such forward-looking statements, including those described in "Risk Factors" of our Form 10-K for the year ended December 31, 2008 as filed with the Securities and Exchange Commission. Synta undertakes no obligation to publicly update forward-looking statements, whether because of new information, future events or otherwise, except as required by law.

SOURCE: Synta Pharmaceuticals Corp.

Synta Pharmaceuticals Corp.
Rob Kloppenburg, 781-541-7125