CARY, NC–Cornerstone Therapeutics Inc. (NASDAQ: CRTX), a specialty pharmaceutical company focused on commercializing products for the hospital and related specialty markets, announced today that the Company received a Complete Response Letter (CRL) from the U.S. Food and Drug Administration (FDA) for its New Drug Application (NDA) for lixivaptan for the treatment of symptomatic hypervolemic and euvolemic hyponatremia associated with heart failure and syndrome of inappropriate antidiuretic hormone (SIADH), respectively.

The Complete Response Letter requests additional clinical and non-clinical information in order for the FDA to consider approval of lixivaptan. The Company intends to request an End-of-Review meeting with the Division of Cardiovascular and Renal Products to better understand the contents of the CRL.

“We are reviewing the Complete Response Letter and will determine the most appropriate next steps for the Lixivaptan program,” said Craig A. Collard, Cornerstone’s Chief Executive Officer. “We believe we have strong clinical data supporting lixivaptan for the treatment of hyponatremia and that a significant unmet need remains for an alternative vaptan in the hospital and community setting.”

Lixivaptan is a highly potent, non-peptide, oral capsule that works by reducing the action of a hormone (vasopressin) that blocks fluid excretion. Lixivaptan acts specifically on the vasopressin-2 receptor in the kidneys, causing water to be excreted while sparing sodium without affecting other electrolytes. Three large clinical trials, two evaluating lixivaptan for SIADH and one for heart failure, met the primary endpoint of producing a significant increase in serum sodium concentration compared to placebo at treatment day seven.

About Hyponatremia
Hyponatremia is a metabolic condition that occurs when there is not enough sodium (salt) in the blood. It is estimated to affect up to six million people in the U.S. with direct medical costs ranging between $1.6 and $3.6 billion annually. It is the most common electrolyte disorder among hospitalized patients and is often diagnosed in patients with heart failure. In the U.S. alone, there are five million heart failure patients, and each year one-fourth of them develop hyponatremia. Other causes of hyponatremia include burns, diuretic medications, kidney disease, liver cirrhosis and SIADH.

About Cornerstone Therapeutics
Cornerstone Therapeutics Inc. (NASDAQ: CRTX), headquartered in Cary, N.C., is a specialty pharmaceutical company focused on commercializing products for the hospital, niche respiratory and related specialty markets. Key elements of the Company’s strategy are to focus its commercial and development efforts in the hospital and related specialty product sector within the U.S. pharmaceutical marketplace; continue to seek out opportunities to acquire companies and marketed and/or registration-stage products that fit within the Company’s focus areas; and generate revenues by marketing approved generic products through the Company’s wholly-owned subsidiary, Aristos Pharmaceuticals, Inc. For more information, visit www.crtx.com.