Genaissance obtains gene test patent
Genaissance Pharmaceuticals has expanded its genetic testing
service, which can analyse key cardiac ion channel proteins
involved in drug-induced cardiac arrhythmias.
The method will help identify experimental drugs that may induce life threatening cardiac arrhythmias before they are brought to market. Drug-induced cardiac arrhythmias that are associated with prolongation of the QT interval on the electrocardiogram have led to the withdrawal from the market of such well- known drugs as the heartburn agent Propulsid (cisapride) and the antihistamine Seldane (terfenadine).
Genaissance has gained the commercial rights to the patent, which details the screening of patients for susceptibility for drug-induced cardiac arrhythmias. It achieves this by testing for a common polymorphism in KCNE1, an important cardiac ion-channel gene.
Drug-induced cardiac arrhythmias continue to represent difficulty in developing safe and effective anti-arrhythmic agents. Drug induced cardiac arrhythmias also occur during treatment with non-cardiac drugs that have unintended effects on cardiac repolarisation. For example, as many as 10 per cent of patients treated with quinidine, sotalol, and ibutilide will develop excessive QT interval prolongation.
"Gaining the right to screen patients for this KCNE1 polymorphism, which increases a patient's risk of developing a drug-induced arrhythmia, is especially critical for FDA-mandated thorough QT safety trials that now occur in early stages of drug development," said Richard Judson, chief scientific officer of Genaissance.
A variety of therapeutic agents commonly used to treat cardiac arrhythmias, along with other non-cardiac drugs, can provoke potentially dangerous disturbances of cardiac rhythm.
By blocking the rapidly activating cardiac delayed rectifier potassium current, (I.sub.Kr), the desired therapeutic effect of many anti-arrhythmic agents is achieved.
Approximately, 1-10 per cent of patients receiving action potential prolonging drugs will develop marked prolongation of the electrocardiographic QT interval or polymorphic ventricular tachycardia.
The patent, which was licensed from Vanderbilt University adds to Genaissance patent portfolio for target genes associated with Long QT syndrome (LQTS). Genaissance has a patent estate of more than 50 issued and pending patents in the United States and other countries relating to five cardiac ion channel genes associated with LQTS: KCNQ1, KCNH2 (HERG), SCN5A, KCNE1, KCNE2.
Episodic cardiac arrhythmia is a cause of sudden death and characteristic of LQTS. LQTS can be inherited (familial) or acquired, as in drug-induced LQT.
Genaissance is currently marketing its proprietary Famillon test, a genetic test for cardiac channelopathies, including LQTS and Brugada Syndrome, to cardiologists and electrophysiologists, who commonly care for these patients.
Genaissance also offers the test to pharmaceutical customers as a tool to understand the contribution of genetics to QT prolongation seen in clinical trial subjects.
