Approval of Invokana, new kind of type 2 diabetes drug, by the U.S. Food and Drug Administration means diabetics have a significant new tool for treating the disease, as well as for losing weight and improving their overall health.
“It’s not hype to say that this is a new class of drug that could provide patients with a lot of beneficial results,” Dr. Zachary Bloomgarden, Clinical Professor in the Department of Medicine, Division of Endocrinology at Mount Sinai School of Medicine and a nationally renowned diabetes educator and lecturer, said about the approval of the new drug, canagliflozin, which will be sold under the brand name Invokana. “The bottom line with this drug is that it controlled blood sugar levels without causing weight gain and caused almost no hypoglycemia. This drug could be the backbone of new treatments for type 2 diabetes.”
How Invokana Works
In development for the last 13 years, Invokana employs a “novel mechanism of action” to lower blood sugar in type 2 diabetics, Bloomgarden says. The medication is a sodium glucose co-transporter 2 (SGLT2) inhibitor, according to the drug’s developer Janssen Pharmaceuticals, Inc., a part of Johnson & Johnson.
Invokana works by inhibiting sodium glucose co-transporter 2, a carrier that aids in the reabsorption of glucose into the bloodstream through the kidneys, which occurs during the process in which blood is filtered through the kidneys. The excess glucose is then flushed out of the body, which is why Invokana also acts as a “potent diuretic,” Bloomgarden said.
“One of the most basic biological factors driving the diabetes and obesity epidemics is that our bodies have evolved to never waste food and energy,” medical journalist Alasdair Wilkins said when describing how Invokana works. “For most species, including our hunter-gatherer ancestors who could never be entirely sure where their next meal would come from, such aggressive conservation of energy made perfect sense. But modern humans live in an era of plentiful food, where there’s far greater danger of eating too much rather than too little. SGLT-1 and SGLT-2 evolved to prevent the loss of seemingly vital sugar by transporting glucose from the kidney back into the body’s circulation, with SGLT-2 reabsorbing 90% of glucose in the kidney and SGLT-1 accounting for the final 10% in the kidney.”
Invokana reduced the A1c of type 2 diabetics more effectively than glimepiride, or Amaryl, which works by increasing insulin production in the pancreas, according to Jimmy Ren, Ph.D., of Janssen Pharmaceuticals. It also worked with about the same effectiveness as sitagliptin, or Januvia, which inhibits enzymes and increases pancreatic function, Ren added.
Invokana Side Effects, Weight Loss
Because Invokana is such a powerful diuretic, it can help lower a person’s systolic blood pressure, which made some clinical trial subjects feel dizzy and even faint in the first three months while taking the drug. For extended periods, however, reducing blood pressure in a population of patients with typically higher than normal blood pressure as a result of their diabetes is a positive side effect.
Additionally, because Invokana blocks absorption of glucose, it could reduce a person’s weight. According to Janssen Pharmaceuticals, clinical trials subjects taking the drug experienced a 3 percent weight loss compared to subjects taking a placebo.
This method of reducing blood sugar by blocking glucose absorption in the kidneys proved safe and effective through nine clinical trials involving 10,285 participants, according to Janssen Pharmaceuticals. The most common side effects experienced were vaginal yeast infections and urinary tract infections, according to the company.
Even though the FDA voted 10 to five to approve Invokana, the jury is still partially out on the drug’s complete safety and the long-term effects of the new class of medication. A drug called dapagliflozin, from Bristol-Myers Squibb and AstraZeneca, that also works as a SGLT2 inhibitor, for instance, was rejected for approval by the FDA in 2012 because of concerns it increased rates of bladder and breast cancers in subjects.
The FDA said they are requiring Janssen Pharmaceuticals to conduct “five post marketing studies for Invokana:
- a cardiovascular outcomes trial;
- an enhanced pharmacovigilance program to monitor for malignancies, serious cases of pancreatitis, severe hypersensitivity reactions, photosensitivity reactions, liver abnormalities, and adverse pregnancy outcomes;
- a bone safety study;
- and two pediatric studies under the Pediatric Research Equity Act (PREA), including a pharmacokinetic and pharmacodynamic study and a safety and efficacy study.”
Should I Take Invokana?
Even though Invokana is a creative and apparently effective new way of reducing blood sugar, Bloomgarden says that metformin, or Glucophage is, and will most likely remain, the primary drug for treating type 2 diabetes. However, Invokana can be taken by those already taking metformin and other medications, according to the FDA.
“Invokana has been studied as a stand-alone therapy and in combination with other type 2 diabetes therapies including metformin, sulfonylurea, pioglitazone, and insulin,” the agency said. The agency also said there are those who cannot and should not take Invokana.
“Invokana should not be used to treat people with type 1 diabetes; in those who have increased ketones in their blood or urine (diabetic ketoacidosis); or in those with severe renal impairment, end stage renal disease, or in patients on dialysis.”
The FDA said Invokana can be used in conjunction with other drugs, such as metformin, in patients as long as they do not have suffer from any kidney function impairment.
Patients won’t have to wait long to get their hands on Invokana if their doctor prescribes it for them. According to company spokesperson Christina Holden, Invokana is already being manufactured and field sales agents are already taking order from doctors. Financial analysts are predicting that the drug will bring in more than $100 million in sales this year and top out at more than $660 million in annual sales by 2016.