DAPA-CKD grows the pool of eligible heart failure patients
A further consequence of the DAPA-CKD findings is that when, as expected, regulatory bodies give dapagliflozin an indication for treating the types of CKD patients enrolled in the trial, it will functionally expand this treatment to an even larger swath of heart failure patients who currently don’t qualify for this treatment, specifically patients with CKD who also have heart failure with preserved ejection fraction (HFpEF). On Oct. 2, 2020, the Food and Drug Administration fast-tracked dapagliflozin for the CKD indication by granting it Breakthrough Therapy Designation based on the DAPA-CKD results.
Results first reported in 2019 from the DAPA-HF trial led to dapagliflozin receiving a labeled indication for treating HFrEF, the types of heart failure patients enrolled in the trial. Direct evidence on the efficacy of SGLT2 inhibitors for patients with HFpEF will not be available until results from a few trials now in progress become available during the next 12 months.
In the meantime, nearly half of patients with HFpEF also have CKD, noted Dr. McMurray, and another large portion of HFpEF patients have type 2 diabetes and hence qualify for SGLT2 inhibitor treatment that way. “Obviously, we would like to know specifically about heart failure outcomes in patients with HFpEF” on SGLT2 inhibitor treatment, he acknowledged. But the recent approval of dapagliflozin for patients with HFrEF and the likely indication coming soon for treating CKD means that the number of patients with heart failure who are not eligible for SGLT2 inhibitor treatment is dwindling down to some extent.
New DAPA-HF results show no drug, device interactions
In a separate session at the HFSA virtual meeting, Dr. McMurray and several collaborators on the DAPA-HF trial presented results from some new analyses. Dr. McMurray looked at the impact of dapagliflozin treatment on the primary endpoint when patients were stratified by the diuretic dosage they received at study entry. The results showed that “the benefits from dapagliflozin were irrespective of the use of background diuretic therapy or the diuretic dose,” he reported. Study findings also showed that roughly three-quarters of patients in the study had no change in their diuretic dosage during the course of the trial, that the fraction of patients who had an increase in their dosage was about the same as those whose diuretic dosage decreased, and that this pattern was similar in both the patients on dapagliflozin and in those randomized to placebo.
Another set of new analyses from DAPA-HF looked at the impact on dapagliflozin efficacy of background medical and device therapies for heart failure, as well as background diabetes therapies. The findings showed no signal of an interaction with background therapies. “The effects of dapagliflozin are incremental and complimentary to conventional therapies for HFrEF,” concluded Lars Kober, MD, a professor and heart failure physician at Copenhagen University Hospital.
DAPA-CKD was funded by AstraZeneca, the company that markets dapagliflozin (Farxiga). Dr. McMurray’s employer, Glasgow University, has received payments from AstraZeneca and several other companies to compensate for his time overseeing various clinical trials. Dr. Kober has received honoraria for speaking on behalf of several companies including AstraZeneca.