Drugmaker Mitsubishi Tanabe Pharma has a history going back almost 340 years, primarily resulting from a number of mergers, acquisitions and takeovers during the 20th Century. However, its current issues with the diabetic drug Invokana began only recently. It was in 2014 that the company entered into a three-year collaboration with AstraZeneca in order to share research and knowledge so as to more quickly produce drugs for the treatment of Type 2 diabetes.
Specifically, the two companies were interested in a condition known as diabetic nephropathy. A common complication of diabetes, it is a progressive disease that attacks clusters of blood vessels in the kidneys (known as glomeruli, literally “ball of yarn”) that are instrumental in filtration of the blood. Untreated, the disorder can lead to hypertension, fluid retention and general swelling and hardening of the renal artery (arteriosclerosis). Eventually, the kidneys fail altogether. At this point, the only realistic option for the patient is dialysis or a kidney transplant. It's a condition that also causes nerve damage in approximately 65% of diabetics in the U.S.
Both Mitsubishi Tanabe and AstraZeneca, along with Johnson & Johnson and Eli Lilly as well as Boehringer-Ingelheim, have developed a class of drugs known as gliflozins. Earlier Type 2 diabetic medications target chemical messengers regulating blood sugar (Actos and Avandia) or slowed down the production of glucose (Januvia). Gliflozins like Invokana inhibit the action of a protein known as SGLT2, which allows the kidneys to reabsorb glucose not used by the body. This excess glucose is then excreted through the urine.
This new class of drugs would supposedly revolutionize the treatment of Type 2 diabetes. Invokana was not the first drug of this class to come to market. In 2011, the European Union approveddapagliflozin for diabetics. Produced and sold by AstraZeneca under the brand name Farxiga, this drug was approved by the U.S. Food and Drug Administration in January of 2014. However, Invokana, which received approval ten months earlier, was the first SGLT2 inhibitor to reach the U.S. market.
Despite numerous clinical trials and long-term studies of Invokana, the new “blockbuster” drug had been on the market less than a month before the FDA began receiving reports of diabetic ketoacidosis, a condition that dangerously lowers blood pH levels, causing a build-up of acids in the bloodstream. Over the next fifteen months, the FDA identified twenty such cases, all of which required emergency medical treatment or hospitalization.
Other side effects associated with Invokana include:
- urinary tract infections
- genital fungal (yeast) infections
- rise in LDL cholesterol levels
- hypotension (low blood pressure)
- heart problems and stroke
What is significant is that while these side effects were revealed by the manufacturers as a result of clinical trials and studies, occurrences of ketoacidosis were not. “This suggests they missed something or intentionally decided not to report it,” says Tim O'Brien, Invokana lawsuit attorney for Levin, Papantonio, Thomas, Mitchell, Rafferty & Proctor P.A.
If evidence winds up proving that the Japanese drug maker was aware of such dangers (or should have known of them) and withheld this information from physicians and patients, it would not be the first time. “We've litigated dozens of cases in which a manufacturer with a profitable product knew of dangerous defects and chose not to inform consumers,” Mr. O'Brien adds. “It's something we intend to find out.”