The adverse-event profile seen in DAPA-HF looked very “clean,” said Dr. Mann, especially compared with the other medical classes recommended in guidelines for patients with HFrEF: the angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), beta-blockers, and mineralocorticoid-receptor antagonists such as spironolactone, and the angiotensin receptor-neprilysin inhibitor (ARNI) sacubitril-valsartan (Entresto). As used in DAPA-HF dapagliflozin also had the advantages of not needing dose titration or laboratory follow-up, as do several of these other drug classes.
“I think dapagliflozin will have a huge uptake [for treating HFrEF], because it will be easy for primary care physicians to prescribe. It will be easier to use than traditional heart failure medications.” Once approved for heart failure use, Dr. Mann predicted a standard dosing regimen for HFrEF patients of an ACE inhibitor, ARB or ARNI, a beta-blocker, a mineralocorticoid-receptor antagonist, and an SGLT2 inhibitor. He suggested that this large and cumbersome collection of medications could conceivably be simplified into a polypill.
He also saw a suggestion in the DAPA-HF results that combining dapagliflozin with the ARB valsartan might have similar efficacy to dapaglifozin plus sacubitril-valsartan, which might also help simplify heart failure treatment. In the trial, 11% of patients received sacubritril-valsartan, and the primary-endpoint reduction compared with placebo in this subgroup was 26%, compared with 25% for patients treated with an ACE inhibitor or ARB. Currently, labeling for sacubitril-valsartan calls for starting a patients on an ACE inhibitor or ARB, titrating them to a stable and effective dosage, and then stopping this regimen to switch to the ARNI. If dapagliflozin is also added, then a simpler approach would be to just start a patient on valsartan, optimize the dosage, and then start dapagliflozin and achieve the same benefit as from sacubitril-valsartan plus dapagliflozin. While an attractive scenario, it needs validation, Dr. Mann said in an interview.
One additional, notable finding from DAPA-HF was that the primary endpoint benefit appeared much stronger in patients with New York Heart Association class II heart failure at entry, two-thirds of the study population, compared with patients with class III or IV HFrEF. Compared with placebo the primary endpoint fell by 37% among the class II patients, a statistically significant difference, but by just 10% in the class III and IV patients, a reduction that was not significant compared with placebo. This too needs more study, commented Dr. Mann, as does the ways by which dapagliflozin and the other SGLT2 inhibitors benefit heart failure patients. Currently the ways by which dapagliflozin produced these results remain unknown.
DAPA-HF randomized a total of 4,744 patients at 410 sites in 20 countries. About 10% of enrolled patients were in the United States.
DAPA-HF was sponsored by AstraZeneca, the company that markets dapagliflozin (Farxiga). AstraZeneca paid Glasgow University to cover Dr. McMurray’s salary during the time he spent working as principal investigator of DAPA-HF. Dr. McMurray had no other relevant disclosures. Dr. Mann has been a consultant to Bristol-Myers Squibb, LivaNova, Novartis, and Tenaya Therapeutics. Dr. Bhatt has received research funding from AstraZeneca, and he has served as a consultant to or received research funding from several other companies.