FDA Approves Cyanokit(R) For Treatment Of Cyanide Poisoning

EMD Pharmaceuticals and Dey, LP, U.S. Affiliates of Merck KGaA of Darmstadt, Germany, jointly announced today that the U.S. Food and Drug Administration (FDA) has approved Cyanokit(R) (hydroxocobalamin for injection), for the treatment of known or suspected cyanide poisoning.

EMD Pharmaceuticals completed the submission of a New Drug Application (NDA) for Cyanokit(R) (hydroxocobalamin for injection) to the FDA in June of 2006. Dey, LP is located in Napa, CA and will market Cyanokit in the US market. Dey, LP expects Cyanokit to be available early in 2007.

Cyanokit's unique mechanism of action makes possible its use in a pre- hospital or hospital setting. It is the first cyanide antidote to be approved in the United States in several decades.

In the U.S., cyanide poisoning is primarily caused by smoke inhalation during closed space structural fires. Additional causes may include accidental or intentional ingestion or exposure during industrial accidents or a terrorist attack involving cyanide.

"We are very pleased with the FDA's decision to approve Cyanokit," said Christy Taylor, Senior Vice President of Marketing, Sales and Business Development for Dey, LP. "Treating cyanide poisoning as soon as possible after exposure is critical to survival. Emergency responders will now have a way to treat people for cyanide poisoning immediately at the scene of a fire, accident or other emergency as well as in the emergency department of a hospital. We anticipate that the availability of Cyanokit will have a significant impact on the survival of those who are affected by cyanide poisoning."

Cyanokit Exhibited Positive Safety, Efficacy Profiles

The FDA approval is supported by efficacy studies in animals and safety studies in healthy adults. These studies demonstrated that Cyanokit is safe and effective in treating cyanide poisoning from smoke inhalation and other causes.

At the American College of Emergency Physicians 2005 Research Forum, investigators Frederic Baud, MD, Medical and Toxicological Critical Care Department, Lariboisiere Hospital, Paris, France and Stephen W. Borron, MD, FACEP of The University of Texas Health Science Center at San Antonio presented the results of several studies including a prospective open-label study(1) carried out in 69 subjects who had been exposed to smoke inhalation from fires. Subjects were over 15 years of age, presented with soot in the mouth or nose and expectoration, and had altered neurological status. The median Cyanokit dose was 5.0 g with a range from 4.0 to 15.0 g.

Fifty of 69 patients, or 73 percent of subjects, survived following treatment with Cyanokit and supportive care. Of the 19 subjects who did not survive, 13 subjects were in initial cardiac arrest at the scene.

Of the 42 subjects with pretreatment cyanide levels considered to be potentially toxic, 28 (67 percent) survived. Of the 19 subjects whose pretreatment cyanide levels were considered potentially lethal, 11 (58 percent) survived. Of the 50 subjects who survived, 9 subjects (18 percent) experienced long-term neurologic effects from cyanide poisoning at hospital discharge.

A study of 136 healthy adult subjects(2) also was conducted to assess the safety, tolerability, and pharmacokinetics of Cyanokit. Side effects observed with Cyanokit were generally transient and self-limiting. The most frequently occurring adverse reactions were injection site reactions; skin rash; chromaturia (urine discoloration), which was reported in all subjects receiving 5.0 g Cyanokit or greater; and erythema (skin redness), which occurred in most subjects receiving 5.0 g Cyanokit or greater. Elevations in blood pressure were observed in some subjects, generally returning to normal within a few hours after administration. People with known hypersensitivity to hydroxocobalamin and /or Vitamin B12 should not be administered Cyanokit.

"These results show that Cyanokit is safe and effective in treating cyanide poisoning, even in patients with potentially lethal concentrations of cyanide in the blood," says Dr. Stephen W. Borron, one of medical advisors to the safety study. "In addition, the side effects experienced by patients were modest and temporary; no severe adverse events related to Cyanokit treatment were observed. These characteristics of a cyanide antidote are very important in an emergent situation requiring rapid, life-saving treatment."

Smoke Inhalation and Cyanide Poisoning

Fire smoke is a common source of cyanide exposure. Cyanide may be produced by the pyrolysis (incomplete burning) of common synthetic or plastic materials as well as from natural materials such as wood, paper and silk. Cyanide is increasingly recognized as a common and dangerous component of fire smoke, adding to the effects of carbon monoxide as a fire smoke toxicant. In fact, cyanide poisoning and carbon monoxide poisoning most often occur together during a fire. Prompt recognition and treatment of cyanide poisoning with an antidote can save lives.

Cyanokit has been used in France for over 10 years in both pre-hospital and hospital settings to treat cyanide poisoning resulting from smoke inhalation, ingestion and other causes. Although recognized in Europe for many years, only recently has the risk of cyanide exposure in fire smoke gained recognition in the U.S. The U.S. maintains one of the highest fire- related death rates of industrialized countries even though the number of fires has steadily decreased over the past two decades. Smoke inhalation is responsible for up to 80 percent of U.S. fire-related injuries and deaths. According to the United States Fire Administration (USFA), in 2004, the most recent year for which statistics are available:

-- 3,900 civilians and 117 firefighters lost their lives in fires, with an additional 17,785 civilians injured as the result of fire

-- Of all civilian fire-related deaths, 83 percent of them occurred in residences

-- An estimated 20,800 residential structure fires are attributed to mattresses, pillows, and bedding materials, all of which are highly likely to contain synthetic materials that release hydrogen cyanide when they smolder

Cyanide is highly toxic by all routes of exposure and may result in rapid onset of serious effects on the nervous, cardiovascular, and respiratory systems, leading to death within minutes to hours. Exposure to lower concentrations of cyanide may produce headache, confusion, nausea, and vomiting followed in some cases by coma and death. The presence and extent of cyanide poisoning are often initially unknown.

There is no widely available, rapid, confirmatory cyanide blood test. Treatment decisions must be made on the basis of clinical history and/or signs and symptoms of cyanide intoxication. If clinical suspicion of cyanide poisoning is high, Cyanokit should be administered without delay.

About Cyanokit

The active ingredient in Cyanokit, hydroxocobalamin, is a precursor of vitamin B12. Hydroxocobalamin works by binding directly to the cyanide ions, creating cyanocobalamin, a natural form of vitamin B12, which is excreted in the urine. Advantages of this approach are that methemoglobin is not produced and the oxygen-carrying capacity of the victim's blood is not lowered. Therefore, Cyanokit is suitable for use in smoke inhalation victims. The most common side effects seen in clinical trials of hydroxocobalamin are: injection site redness; temporary discoloration of the skin, urine and mucous membranes; and transient elevations in blood pressure.

The initial dose of Cyanokit for adults is 5.0 g, (2 vials) administered by intravenous infusion. Depending upon the severity of the poisoning and the clinical response, a second dose of 5.0 g may be administered up to a total dose of 10.0 g.

Cyanokit has been approved for marketing in France (marketed under the same name by Merck Sante s.a.s.) since 1996 for the treatment of cyanide poisoning.

For full prescribing information, please contact 1-800-429-7751 or visit http://www.dey.com.

About EMD Pharmaceuticals, Inc.

A U.S. Affiliate of Merck KGaA of Darmstadt, Germany, EMD Pharmaceuticals is a specialty pharmaceutical company with a focus on clinical development, regulatory affairs, and business development in support of providing targeted therapies for cancer treatment and other specialty areas, including central nervous system disorders and cyanide poisoning. EMD is headquartered in Durham, N.C. Additional information about EMD is available at http://www.emdpharmaceuticals.com.

About Dey, LP.

A U.S. Affiliate of Merck KGaA of Darmstadt, Germany, DEY, L.P. develops, manufactures, and markets innovative airway, allergy and emergency medications that save and improve lives. The Company puts "patients first" through integrated healthcare delivery solutions, and facilitates efficient, cost- effective partnerships with its customers. DEY is committed to investing in its employees and the communities in which they live. Additional information about Dey, LP is available at http://www.dey.com.

(1) Borron SW et al. "Hydroxocobalamin for Empiric Treatment of Smoke Inhalation-Associated Cyanide Poisoning: Results of a Prospective Study in the Prehosptial Setting" poster presentation presented at the American College of Emergency Physicians 2005 Research Forum.

(2) Uhl W. "Hemodynamic Effects of Hydroxocobalamin in Healthy Volunteers" poster presentation presented at the American College of Emergency Physicians 2006 Research Forum.

EMD Pharmaceuticals; Dey, LP
http://www.emdpharmaceuticals.com