Verapamil results ‘brilliant’ but more work needed
In the verapamil part of the CLVer trial, by 52 weeks, verapamil doses in the youth who received it ranged from 120-360 mg/day based on weight and tolerance.
The primary outcome, C-peptide area under the curve, stayed stable, from 0.66 pmol/mL at baseline to 0.65 pmol/mL at 52 weeks in the verapamil group, compared with a drop from 0.60 pmol/mL down to 0.44 pmol/mL with placebo, a significant difference of 0.14 pmol/mL (P = .04), representing a 30% higher C-peptide level in the verapamil group.
“For us, this is a phenomenally exciting result,” Dr. Forlenza commented during his presentation.
At 52 weeks, A1c was 6.6% in the verapamil group versus 6.9% with placebo, which was not significantly different. Daily insulin dose was 0.65 versus 0.74 units/kg per day, respectively, also not significantly different.
One severe hypoglycemic event occurred in each group, and one diabetic ketoacidosis event occurred in the placebo group. In the verapamil group, three participants experienced “nonserious” electrocardiogram abnormalities and one had hypertension.
Dr. Biester said he isn’t “that concerned” about the small number of mild ECG abnormalities seen in the study with verapamil, as this is a known side effect. But overall, he said, “I would think that for a recommendation for routine use it’s too early after one study, even though the results are brilliant.”
He noted that he is involved in a similar ongoing study of verapamil in adults with new-onset type 1 diabetes, called Ver-A-T1D.
No C-peptide effect of tight glycemic control: ‘A tough pill’
In the AID part of the study, the 113 participants were randomized 2:1 to one of two commercially available AID systems (Tandem t:slim X2 with Control-IQ or Medtronic 670G or 780G) plus frequent contact (a median of 35 times) by study staff, or standard management using a continuous glucose monitor (CGM) with an insulin pump or multiple daily injections.
At 52 weeks, A1c was 6.5% for the intensive group versus 7.1% with standard care, a significant difference. Time in blood glucose range of 70-180 mg/dL was significantly longer with intensive management, at 78%, compared with standard care, at 64%.
Nonetheless, the change in C-peptide area under the curve did not differ between the two groups, decreasing from 0.57 pmol/mL at baseline to 0.45 pmol/mL at 52 weeks with the AID system, compared with a decrease from 0.60 pmol/L down to 0.50 pmol/L with standard care (P = .89).
Dr. Forlenza commented that the hypothesis that tight glycemic control would delay the decline in C-peptide secretion “is something I think a lot of endocrinologists assumed to be true and something I’ve heard lots of colleagues over the years talk about.”
Consequently, he said these findings are “a tough pill for us to swallow ... but it’s important for us in the field to understand.”
“Even with frequent contacts that are well above the level we’d be able to do in standard clinical care, and even with use of the most advanced AID systems we have ... we saw absolutely no difference in stimulated C-peptide levels at any of the timepoints throughout the first year or at 52 weeks.”
“So, in our opinion, this,” combined with a prior study from 2022, “should put this hypothesis to rest,” he said.
“Excellent glycemic control has a benefit in and of itself, but it was not a successful intervention for beta-cell preservation.”
Dr. Forlenza has reported serving as a consultant, speaker, or advisory board member for Medtronic, Dexcom, Abbott, Tandem Diabetes Care, Insulet, Lilly, and Beta Bionics, and his institution has also received funding on his behalf for research grants from these companies. Dr. Biester has reported receiving speaker’s fees from DexCom, Medtronic, Novo Nordisk, F. Hoffmann–La Roche, Sanofi, and Ypsomed Holding; serving on advisory boards for Ascensia Diabetes Care Holdings, AstraZeneca, DexCom, and Medtronic; and receiving personal fees from SYNLAB; and is a member of the European Commission Expert Panel for Medical Devices for Endocrinology and Diabetes. Dr. Couper has reported no relevant financial relationships.
The rationale for the companion CLVer analysis of the effect of reducing glucose toxicity via tight glycemic control on C-peptide progression dates back to an inpatient study published in 1989 involving 26 adolescents using an early artificial pancreas prototype called a Biostator, in which beta-cell preservation was achieved. However, two more recent studies of this approach, including one published in late 2022, did not show a difference. The CLVer analysis involved 113 participants randomized 2:1 to one of two commercially available AID systems (Tandem t:slim X2 with Control-IQ or Medtronic 670G or 780G) plus frequent contact by study staff, or standard management using a CGM with a pump or multiple daily injections.
A version of this article originally appeared on Medscape.com.