How results compare with prior CVOTs
In some ways, these results seemed to contrast with outcomes from the CVOTs for the other SGLT2 inhibitors, which all showed at least two statistically significant benefits for major endpoints when compared with placebo.
Dr. Darren K. McGuire
As summarized in a new meta-analysis of all the CVOTs by Darren K. McGuire, MD, a cardiologist and professor of medicine at the University of Texas, Dallas, both empagliflozin and canagliflozin showed statistically significant superiority compared with placebo for their trial’s primary, combined major cardiovascular adverse event endpoint, but dapagliflozin and ertugliflozin did not. Empagliflozin was the sole SGLT2 inhibitor to show a statistically significant cut in cardiovascular deaths, compared with placebo.
The primary, composite renal efficacy endpoints used in these trials were hardest to compare because they differed from study to study, but unlike ertugliflozin, all the other three drugs in the class showed a statistically significant improvement, compared with placebo, for their respective renal outcomes. On the other hand, the pattern of estimated glomerular filtration rates measured at multiple times during the various trials showed a high level of consistency across the CVOTs.
The greatest consistently among the major endpoints across the trials was for heart failure hospitalization. All four agents showed statistically significant improvements, compared with placebo, and all four had roughly equal magnitudes of effect, a cut in event rates by about one-third.
“The greatest magnitude of benefit is for reductions in heart failure hospitalizations and for renal outcomes,” with the heart failure outcomes the “most consistent” across the studies and the renal outcomes “largely consistent,” concluded Dr. McGuire. All together, the five CVOTs for these four SGLT2 inhibitors involved more than 46,000 patients.
Dr. Mark E. Cooper
“A lot of data suggest these are all class effects,” that are roughly similar across all four of these SGLT2 inhibitors, commented Mark E. Cooper, MBBS, a professor and head of the department of diabetes at Monash University, Melbourne, and designated discussant for the study.
There was “clear homogeneity” between the VERTIS-CV results for hospitalization for heart failure and the other CVOTs, he noted. “I think there is a difference” in the cardiovascular death outcomes, specifically the sole statistically significant, 38% relative risk reduction with empagliflozin that stood out from the other CVOTs, but this difference is “totally unexplained,” added Dr. Cooper. “To really determine differences you’d need head-to-head studies that are unlikely to happen.”
The results of new SGLT2 inhibitor meta-analysis appeared to also “support contemporary society recommendations to prioritize the use of SGLT2 inhibitors independent of glucose-control considerations in patients with type 2 diabetes with or at high risk for cardiovascular and renal complications,” said Dr. McGuire.
“The guidelines have it right. Now it’s on us to implement these treatments to appropriate patients,” concluded Dr. Cannon.
Study details
VERTIS-CV (Cardiovascular Outcomes Following Ertugliflozin Treatment in Type 2 Diabetes Mellitus Participants With Vascular Disease) enrolled and followed patients with type 2 diabetes and established atherosclerotic cardiovascular disease at 531 centers in 34 countries during December 2013–December 2019. Other effects from ertugliflozin recorded during the trial were consistent with prior studies of the drug, which is already FDA approved for glycemic control: Compared with placebo, ertugliflozin treatment reduced hemoglobin A1c by an average of 0.5% after 1 year, cut average body weight by about 2.5 kg after 1 year with additional modest weight loss, during subsequent years on the drug, and reduced systolic blood pressure by about 3 mm Hg after 1 year.
The drug’s safety profile was generally reassuring and consistent with prior studies of this drug and others in the class, with overall no increase in total adverse events or serious adverse events, compared with placebo, and modestly increased rates of urinary tract and mycotic genital infections.
VERTIS-CV was sponsored by Merck and Pfizer, the companies that market ertugliflozin (Steglatro). Dr. Cannon has received research funding and fees from Merck and Pfizer and from several other companies. Dr. McGuire has received honoraria from Merck, has been a consultant to Pfizer, and has had similar relationships with several other companies. Dr. Cooper has been an advisor to and received honoraria from Merck. He has also received honoraria from or been an adviser to AstraZeneca, Boehringer Ingelheim, Lilly, MundiPharma, Novartis, Reata, and Servier, and he has received research funding from Boehringer Ingelheim and Novo Nordisk.