Invokana Risk of Heart Problems Raised Concerns Before Approval

As concerns continue to mount over the potential side effects of Invokana, Johnson & Johnson’s new-generation diabetes drug, a look back at the FDA’s approval process for the medication indicates that red flags were raised about the potential risk of heart problems before the drug hit the market. 

Invokana (canagliflozin) was introduced by Johnson & Johnson’s Janssen subdiairy in March 2013, as the first member of a new class of diabetes drugs. The medication works by inhibiting a particular function of the kidneys, allowing an increased amount of sugar to be excreted in the urine. However, concerns have emerged about several potential health risks that users may face.

Last month, the FDA issued a warning about the potential link between Invokana and ketoacidosis, which involves the build up of dangerously high acid levels in the blood, which may result in hospitalization or even death. In addition, a recent independent review of FDA adverse event reports submitted since the drug was introduced suggested a potential risk of kidney failure with Invokana, as well.

Amid these rising concerns, questions are being raised about the approval process for the new drug and whether the minimal benefits provided in treating type 2 diabetes justify the potential health risks.

A review of information considered by the FDA’s Endocrinologic and Metabolic Drug Advisory Committee in January 2013, prior to Invokana’s approval, raises further questions about the safety of this new class of diabetes drugs, suggesting that potential Invokana heart risks were considered before the drug was approved.

According to official minutes (PDF) from the FDA panel meeting, there were signs in clinical trials that Invokana may be associated with an increased risk of major adverse cardiovascular events (MACE+), such as heart attacks, strokes or other similar problems.

In one early trial, there were 13 cardiovascular events in the Invokana group, while there was only one in the placebo group. However, the committee noted that the Invokana users outranked the placebo group two-to-one and pointed to other factors that may have led to false conclusions about Invokana heart risk.

In an 8 to 7 vote, committee members expressed concerns about excluding signs of a high risk margin for Invokana heart problems. A majority of the advisory committee “expressed some level of concern over the increased stroke incidence, low-density cholesterol, and MACE+ events at thirty days, but described a general comfort with the data overall,” the meeting’s minutes note. “These committee members generally discussed a need for a longer period of exposure, particularly for a drug that treats a chronic disease.”

Ultimately, however, the panel voted 10 to 5 to recommend approval of Invokana for the treatment of type 2 diabetes. While the advisory committee votes are not binding on the FDA, the agency often follows their advice and Invokana was approved for marketing in the U.S. only a few months later.

Invokana Health Risks

Over the first two years Invokana was on the market in the U.S., the diabetes drug was aggressively marketed by Johnson & Johnson’s Janssen unit, resulting in rapid sales growth and a dominant position within this new class of medications. However, as more and more individuals are switched to this diabetes drug, it appears that Invokana risks are surfacing that may suggest the drug was not thoroughly researched before it was introduced and that inadequate warnings may have been provided for potential users and the medical community.

On May 15, the FDA issued a drug safety communication to warn about the risk of ketoacidosis from Invokana and other sodium-glucose cotransporter-2 (SGLT2) inhibitors. The U.S. drug regulators indicated that at least 20 cases of diabetic ketoacidosis (DKA) were identified during the first 15 months Invokana was on the market, with all of the cases involving hospitalization or emergency room treatment. The agency is continuing to review whether additional warnings or prescribing information is needed for this new class of drugs.

The same month as the FDA warnings, the Institute of Safe Medication Practices (ISMP) released a report that independently evaluates adverse event reports submitted to the FDA, identifying potential safety signals involving kidney toxicity and raising questions about whether the potential Invokana risks may actually outweigh the benefits provided by the diabetes drug.

During the first year Invokana was on the market, ISMP highlighted 457 serious adverse event reports submitted to the FDA involving complications from Invokana. These adverse event reports typically only account for a small portion of the total problems associated with prescription medications on the market.

Many of the reported Invokana problems involved kidney failure, kidney impairment or problems with kidney stones, urinary tract infections, dehydration, hypersensitivity and abnormal weight loss. Looking at reports to the FDA’s adverse event reporting system, the ISMP found that Invokana received more serious adverse event reports than 92% of the other drugs regularly monitored by the group.

During the FDA advisory meeting’s discussion on potential Invokana heart problems, one of the committee members warned that “because this drug acts as an osmotic diuretic, there could be a wider impact on the function of the kidneys than is easily understood.” The ISMP report also noted that, given how Invokana is designed, some potential kidney function risks should have been an obvious threat.

Given the emerging safety concerns and rush to market this new class of diabetes drug, some product liability lawyers are now reviewing whether individuals who suffered an injury may be entitled to financial compensation through an Invokana lawsuit as a result of the drug makers’ failure to adequately research the potential risks and warn about the side effects.