On January 8, the US Food and Drug Administration (FDA) approved the oral Type 2 diabetes medicine Farxiga (generic name dapagliflozin), a joint development of Bristol-Myers Squibb and AstraZeneca. Farxiga will join Invokana (canagliflozin) as a member of the class of drugs known as sodium-glucose cotransporter 2 (SGLT2) inhibitors.
In the process of filtering the blood, the kidneys typically reabsorb all the filtered glucose and return it to the bloodstream. One of the main proteins responsible for this reabsorption is SGLT2. By inhibiting the action of SGLT2, Farxiga blocks the reabsorption of glucose by the kidneys, promoting a loss of glucose in the urine and lowering blood glucose levels.
The medicine, which is already available in Europe under the brand name Forxiga, was initially denied approval in 2012 over a lack of information about its risks and benefits. In mid-December of 2013, an FDA advisory panel voted 13 to 1 in favor of approving the medicine, and 10 to 4 that it had an acceptable cardiovascular risk level.
Farxiga tablets are approved for use in conjunction with diet and exercise in adults with Type 2 diabetes alone or in combination with metformin, Actos (pioglitazone), Amaryl (glimepiride), Januvia (sitagliptin), and insulin.
The medicine comes in tablet strengths of 5 milligrams and 10 milligrams. The recommended starting dose is 5 milligrams once daily, taken in the morning with or without food. In certain people requiring increased blood glucose control, the dose can be increased to up to 10 milligrams daily.
The safety and effectiveness of Farxiga were established through 16 clinical trials, involving more than 9,400 people with Type 2 diabetes, that showed improvements in A1C levels (a measure of blood glucose control over the previous 2–3 months).
This medicine should not be used to treat Type 1 diabetes or diabetic ketoacidosis (a potentially life-threatening condition marked by a chemical imbalance in the body). It should also not be used in people who have kidney problems.
Because an increased number of bladder cancers were diagnosed in people using Farxiga in clinical trials, it is also not recommended for those who have active bladder cancer. People with a history of bladder cancer should talk to their health-care providers before using the medicine.
The FDA is requiring six trials of Farxiga once it is on the market, including one focusing on cardiovascular events; an “enhanced pharmacovigilance program” to monitor liver abnormalities and adverse pregnancy outcomes; two studies looking at how the drug works and how safe and effective it is in children; an assessment of bladder cancer risk; and a study looking at the medicine’s effects on bladder tumors in rodents.
Because of its diuretic effect, Farxiga may cause postural hypotension, or sudden low blood pressure upon standing; this can cause symptoms such as dizziness or fainting. The most common side effects of Farxiga are genital fungal infections and urinary tract infections.
For more information, see the press release on the FDA’s Web site.