The FDA issued a Complete Response Letter to Janssen, telling the drugmaker it needs more data about the experimental canagliflozin-metformin treatment for diabetes. The Johnson & Johnson subsidiary said in a statement that the FDA wants data indicating that canagliflozin—known by the brand Invokana, approved earlier this year—is as effective in the combined form as it is when used as a standalone treatment.

PMLive notes that the CRL is not much of a setback for Janssen, because doctors can prescribe the two drugs separately if they want to use them in tandem. The site also notes that the combination is not a unique one—Bristol-Myers Squibb and AstraZeneca are already marketing a dapagliflozin-metformin mix abroad under the brand Xigduo.