A study of effectiveness and safety of the type 2 diabetes drug Farxiga shows that whilst it is effective in reducing HbA1c, weight and systolic blood pressure it is also linked with higher rates of kidney damage.

Farxiga, which is also known by the medical name dapagliflozin, is a relatively new drug in the SGLT-2 inhibitors class of drugs. Because the drug is new, long term safety of the drug is not yet known and therefore studies are currently being run, such as this one, to assess whether the effectiveness of the drug outweighs any health risks.

The study was carried out over 24 weeks with an additional 28 weeks extension period. During the first 24 weeks, the patients were unaware whether they were taking Farxiga or a placebo pill. Effectiveness of the drug was measured by the number of participants that achieved a 0.5% decrease in A1c levels, a 3% reduction in body weight and a reduction in systolic blood pressure of 3 mmHg.

As part of the safety assessment, rates of heart events, renal failure and impairment, low blood glucose and low blood pressure levels and genital and urinary tract infections were recorded.

The study showed that 11.7% of patients taking Farxiga met all three of the study targets (A1c, body weight and systolic blood pressure reduction) which compared with just 0.9% of those taking placebo. The study showed no increased risk associated with Farxiga in terms of heart problems but indicate greater risks of renal failure or impairment (kidney damage).

People with type 2 diabetes have a significantly higher risk of kidney disease than the rest of the population and therefore the fact that Farxiga is linked with a further increase in risk of kidney problems will need to be taken seriously by health regulators and physicians when considering prescribing the drug.

Additional studies are being carried out to assess kidney safety in more detail, however, these studies will not be completed until June 2019. For now, doctors and patients will need to weigh up whether the benefits of the treatment, such as on body weight and A1c reduction are strong enough to outweigh the possible risks of reduced kidney function.

The study was published online on 7 April of the Diabetes Care journal.