Cytokinetics, Incorporated Reports Second Quarter 2005 Financial Results

Company Announces the Initiation of Two Additional Clinical Trials for Ispinesib and the Advancement of its Lead Cardiac Myosin Activator, CK-1827452

South San Francisco, CA. - July 27, 2005 - Cytokinetics, Incorporated (Nasdaq: CYTK) reported revenues from research and development collaborations of $2.3 million for the second quarter of 2005. Net loss for the second quarter of 2005 was $10.5 million, or $0.37 per share. As of June 30, 2005, cash, cash equivalents, restricted cash and marketable securities totaled $94.2 million.

"We are pleased to report the initiation of two additional clinical trials involving ispinesib, our novel kinesin spindle protein (KSP) inhibitor, bringing the number of ongoing Phase II clinical trials being conducted either by GlaxoSmithKline (GSK) or the National Cancer Institute (NCI) for our leading drug candidate to eight in multiple settings of advanced cancer," stated James H. Sabry, M.D., Ph.D. President and Chief Executive Officer. "In addition, interim Phase I data relating to SB-743921 were presented at the recent American Society of Clinical Oncology meetings. Furthermore, we made significant progress in setting the stage for the initiation of a clinical trial for CK-1827452, our lead cardiac myosin activator. We look forward to initiating clinical trials of this compound, our third drug candidate, in 2005."

Company Highlights
In June, GlaxoSmithKline (GSK) completed patient treatment in the platinum-refractory arm of a Phase II clinical trial evaluating ispinesib as monotherapy in the second-line treatment of patients with non-small cell lung cancer (NSCLC). GSK is collecting data from the investigative centers and will be meeting with Cytokinetics to evaluate data arising from this arm of the study. Data relating to the safety, tolerability and potential efficacy of ispinesib in platinum-refractory patients enrolled in this Phase II study are expected to be announced during the third quarter. GSK continues to enroll patients in the platinum-sensitive arm of this clinical trial; data from this arm of the clinical trial are expected by the year end.

GSK continued to enroll patients in two additional Phase II clinical trials, one evaluating ispinesib as second-line treatment for patients with advanced ovarian cancer and the other evaluating ispinesib as second- or third-line line treatment for patients with advanced breast cancer. Data from both of these Phase II clinical trials are anticipated in 2005.

GSK continued to enroll patients in three dose-escalating Phase Ib clinical trials. Each of these clinical trials are designed to evaluate the safety, tolerability, and pharmacokinetics of ispinesib in combination with a leading anti-cancer therapeutic, one in combination with carboplatin, the second in combination with capecitabine, and the third in combination with docetaxel. Data from each of these clinical trials are anticipated in 2005.

The National Cancer Institute (NCI), in collaboration with GSK, initiated patient enrollment in two additional Phase II clinical trials of ispinesib. One clinical trial is evaluating the potential efficacy of ispinesib in the first-line or second-line treatment of patients with head and neck cancers. The other clinical trial is evaluating the potential efficacy of ispinesib for the second-line treatment of patients with hormone-refractory prostate cancer.

The NCI continued to enroll patients in three additional Phase II clinical trials evaluating the potential efficacy of ispinesib in the second-line treatment of patients with colorectal cancer, in the first-line treatment of patients with hepatocellular cancer and in the first-line treatment of patients with melanoma. In addition, the NCI plans to initiate an additional Phase II clinical trial to evaluate the potential efficacy of ispinesib as second-line treatment of patients with renal cell cancer.

The NCI continued patient enrollment in two additional Phase I clinical trials designed to evaluate the safety, tolerability and pharmacokinetics of ispinesib on an alternative dosing schedule. One clinical trial is enrolling patients with advanced solid tumors that have failed to respond to all standard therapies and the other clinical trial is enrolling patients with acute leukemia, chronic myelogenous leukemia or advanced myelodysplastic syndromes.

Data relating to SB-743921, a second KSP inhibitor, were presented at the 2005 Annual Meeting of the American Society of Clinical Oncology (ASCO) in May. The data presented were from 20 patients who collectively had a variety of advanced solid tumors and received doses of SB-743921 intravenously every 21 days. While determination of the maximum tolerated dose (MTD) is still ongoing, SB-743291 appears to have an acceptable tolerability profile for patients suffering from advanced solid tumors. Notably, neurotoxicities, mucositis, thrombocytopenia, alopecia and nausea/vomiting requiring pre-medication were not observed. The dose-limiting toxicities observed to date are prolonged neutropenia, febrile neutropenia (with or without infection), elevated transaminases, hyperbilirubinemia and hyponatremia.

Cytokinetics continued preclinical development activities with CK-1827452, a novel cardiac myosin activator, discovered as a potential treatment for heart failure and selected for development earlier this year. During the second quarter, the company qualified an investigative site in the United Kingdom for the first clinical trial of CK-1827452 under an Investigational Medicinal Product Dossier (IMPD). The center is qualified for the Phase I clinical trial we have designed which requires careful timing of blood sampling, electrocardiography and echocardiography and other careful measurements. The Phase I clinical trials program is expected to commence in 2005. Preclinical data relating to CK-1827452 will be presented at the Heart Failure Society of America Annual Meeting in September.

Financials
Revenues from research and development collaborations for the second quarter of 2005 were $2.3 million, compared to revenues in the second quarter of 2004 of $2.9 million. Revenues included payments for research collaborations with GSK and AstraZeneca. The decline in collaborative research revenues for the second quarter of 2005, as compared to the second quarter of 2004, was primarily the result of a reduction in funding of $0.6 million by GSK in the second quarter of 2005.

Total research and development (R&D) expenses for the second quarter of 2005 were $10.0 million compared to $9.8 million for the same period in 2004.

Total general and administrative (G&A) expenses for the second quarter of 2005 were $3.4 million compared to $2.6 million in the second quarter of 2004. The increased spending in the second quarter of 2005, over the second quarter in 2004 was primarily due to increased personnel expenses and additional outside services associated with the cost of being a public company.

The net loss for the three months ended June 30, 2005, was $10.5 million, or $0.37 per share. This compares to a net loss for the same period in 2004 of $9.2 million, or $0.46 per share.

Cytokinetics also reported results of its operations for the six months ended June 30, 2005. Revenues from research, development collaborations and grants for the six months ended June 30, 2005 were $4.9 million, compared to revenues of $8.8 million for the same period in 2004. The decline in collaborative research revenues for the first six months of 2005, as compared to the same period in 2004, was primarily the result of the receipt of a $3.0 million milestone from GSK for the initiation of Phase II clinical trials for ispinesib earned in the first quarter of 2004, along with a decrease in funding of $0.8 million in the first six months of 2005.

Total R&D expenses for the six months ended June 30, 2005 were $20.6 million, compared to $19.1 million for the same period in 2004. Expenses related to the development of the company's drug candidates for the treatment of congestive heart failure and expenses related to research programs were the primary reasons for the increased spending in 2005.

Total G&A expenses for the six months ended June 30, 2005 were $6.5 million compared to $5.1 million for the same period in 2004. The increased spending in the first six months of 2005, over the same period in 2004, was primarily due to increased personnel expenses and additional outside services associated with the cost of being a public company.

The net loss for the six months ended June 30, 2005, was $21.1 million, or $0.74 per share. This compares to a net loss for the same period in 2004 of $15.2 million, or $1.35 per share. The per share amounts for the first six months of 2004 were derived from the weighted average shares of common stock outstanding for the period, and does include the preferred shares outstanding that converted to common stock subsequent to the company's initial public offering on April 29, 2004.