AstraZeneca’s combination of two of its main type 2 diabetes treatments, Forxiga and Onglyza, has had its application turned down by the FDA.

The company said in a statement that the regulator had issued a Complete Response Letter (CRL) saying that more clinical data are required to support the approval of the combo. 

“AstraZeneca will work closely with the FDA to determine the appropriate next steps for the NDA and remains committed to the development of the Onglyza (saxagliptin)/Forxiga (dapagliflozin) fixed-dose combination,” the company added.

“This announcement does not affect ongoing interactions with other health authorities as part of these individual application procedures. Based on the information available, the CRL is not expected to affect individual components of Onglyza or Forxiga, which are approved for the treatment of adult patients with type 2 diabetes.”

The drug combo is still under review by the EMA.

AZ has previously been enthusiastic about touting positive results from the combination drug, which showed ‘significant’ greater reductions in HbA1c compared to the monotherapies in a Phase III trial.

But Onglyza is one of several DPP-4 inhibitor drugs that were under investigation in the US for possible links to increased risk of heart failure. The FDA concluded that the safety profile of the drug is acceptable but its label should carry information about the increased risk of death.