Presentation to be Subject of ECCO News Briefing

LEXINGTON, Mass.--(BUSINESS WIRE)--Sept. 18, 2007--Synta Pharmaceuticals Corp., (NASDAQ: SNTA) announced that Anthony Williams, M.D., Vice President, Clinical Research, Synta will present new clinical data on STA-4783 in combination with paclitaxel compared to paclitaxel alone in the treatment of metastatic melanoma at the European Conference on Clinical Oncology (ECCO) on September 26, 2007 in Barcelona, Spain. The presentation will also be featured in an ECCO press briefing at 11:00 AM local time on the same day.

Synta has announced that it plans to initiate an international Phase 3 clinical trial to investigate STA-4783 as a first-line therapy for patients with metastatic melanoma in the third quarter of 2007.

About STA-4783

STA-4783 is a novel, injectable, drug candidate that kills cancer cells by elevating oxidative stress levels beyond a breaking point, triggering programmed cell death. In preclinical models STA-4783 showed potent killing of a broad range of cancer cell types at high doses, and an ability to strongly enhance the efficacy of certain chemotherapy agents, with minimal additional toxicity, at moderate doses. In a recent 21-center, double-blind, randomized, controlled Phase 2b clinical trial in 81 patients with metastatic melanoma, STA-4783 in combination with paclitaxel met the primary endpoint - doubling the median time patients survived without their disease progressing - compared to paclitaxel alone (p=0.035). STA-4783 is now entering a pivotal, confirmatory Phase 3 clinical trial in melanoma. Phase 2 trials in other indications, and in combination with other agents, are planned.

About Metastatic Melanoma

Melanoma, the most deadly form of skin cancer, arises from melanocytes, the pigment-producing cells of the skin. According to the American Cancer Society, melanoma accounts for approximately five percent of all skin cancers but causes about 75% of all skin cancer-related deaths. An estimated 60,000 people will be diagnosed and nearly 8,200 people will die from melanoma this year in the U.S. alone. If diagnosed and surgically removed while localized in the outermost skin layer, melanoma is potentially curable; however, for patients with metastatic disease the prognosis is poor with limited available treatments and an expected survival of only six to nine months. The incidence of melanoma has increased more rapidly than any other cancer during the past ten years. The FDA has not approved a novel, small molecule drug for the treatment of metastatic melanoma in over 30 years.

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 discovered and developed internally. For more information, please see 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 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, 2006 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.

    CONTACT: Synta Pharmaceuticals Corp.
             Rob Kloppenburg, 781-541-7125
             or
             Yates Associates
             Adriana Jenkins, 617-710-8350

    SOURCE: Synta Pharmaceuticals Corp.