ADA Sessions Spotlight Powerful Weapons Against Diabetes
Several hopeful trends emerged from this year’s ADA Scientific Sessions in Philadelphia, held June 8 through 12.
· SGLT2 inhibitors are a class of drugs upon which big pharmaceutical companies are now focusing major attention. In the meantime, other drugs such as Januvia and Bydureon continue battling for market share with robust comparison studies.
· Bariatric surgery continues its push as a major alternative to medication in the treatment of type 2s.
· For both type 1s and type 2s, positive developments include a new insulin analog from Lilly Boehringer, a needleless continuous glucose monitor that has shown a high degree of accuracy, and an insulin analog under development by Lilly Boehringer that assists or surpasses insulin glargine.
The Rise of SGLT2 Inhibitors
SGLT2 inhibitors are an emerging class of type 2 diabetes drugs that work differently from older drugs that increase insulin production and effectiveness or stop the liver from producing too much glucose.
SGLT, which stands for sodium-glucose transporter, refers to a process by which the kidneys process glucose and then return it to the bloodstream. By interfering with this process so that glucose is excreted rather than retained, an SGLT inhibitor gives type 2 patients another means of glycemic control.
At the ADA sessions, pharmaceutical companies presented current studies on three SGLT2 inhibitors:
• Janssen Research presented results from five phase 3 clinical studies of canagliflozin as a monotherapy and in a head-to-head comparison with sitagliptin. In both cases, Janssen reports, type 2 patients taking canagliflozin experienced lower A1Cs, greater weight loss, lower blood pressure, and higher HDL cholesterol than patients on sitagliptin. Janssen has submitted canagliflozin to the FDA for approval as a type 2 therapy.
• Bristol-Myers Squibb reported that its SGLT2 inhibitor, dapagliflozin, produced “significant reductions” in blood sugar levels when used over a 48-week period in conjunction with sitagliptin. The study of 447 adult type 2s compared a placebo to a combination of sitagliptin and dapagliflozin in patients whose sitagliptin or sitagliptin/metformin therapy no longer produced the desired level of glycemic control. Bristol-Myers has applied to the FDA for approval to market dapagliflozin. Pending approval, the agency has asked the company for more information on the drug’s benefit-risk profile.
• Results from a 90-week study showed that empagliflozin from Eli Lilly and Boehringer Ingelheim Pharmaceuticals reduced A1C levels and body weight when used alone or as an add-on to metformin. The partners also reported that the empagliflozin/metformin combination outperformed sitagliptin. Empagliflozin is currently in a phase 3 clinical trial that will enroll 14,500 participants.
The Drumbeat Increases for Bariatric Surgery
Cincinnati-based Ethicon Endo-Surgery (EES) presented results from 13 studies on the use of bariatric surgery as an effective treatment for diabetes and obesity. The EES studies looked at finding less invasive methods to perform the surgeries, ways to target the surgeries at specific metabolic disorders, and postsurgical effects of bariatric surgery.
Bariatric surgery, which alters the upper digestive system to reduce hunger pangs and the quantity of food the body can digest at any one time, has led to remarkable remissions in type 2 patients who were originally being treated for morbid obesity. Surgeons noted that many type 2s experienced a total remission of their diabetes symptoms after bariatric surgery, with blood glucose counts often returning to normal, nondiabetic levels. As a result, there has been more discussion over the past three years about making the surgery available to less-obese type 2s, under insurance coverage as a diabetes therapy.
Meanwhile, Massachusetts-based GI Dynamics announced that a one-year study of its EndoBarrier® device showed that obese type 2s using it averaged a 20 percent greater decline in their A1Cs than patients who did not use the device. They also enjoyed a weight loss of 9.3 percent, compared to a 5.7 percent weight loss among control group members.
EndoBarrier is a thin, flexible liner that surgeons place in the upper intestine during a nonsurgical procedure. (The device is inserted through the esophagus while the patient is in twilight sleep.) The barrier’s location affects the action of hormones that are involved in insulin sensitivity, glucose metabolism, and feelings of satiety. The device is currently being marketed in Europe and Australia.
Therapies Beneficial to Both Type 1s and Type 2s
Echo Therapeutics discussed progress on its Symphony® tCGM System, a continuous glucose monitoring system that is both wireless and needle-free. It works in combination with the company’s Prelude SkinPrep® System, which uses an electrical current to remove 0.1 mm of skin where the Symphony device will be placed. The shallow abrasion to the skin, which is not visible, allows Symphony to detect glucose levels when attached to that spot on a user’s body.
Readings are collected through the skin (the “t” in tCGM means “transdermal”). According to Echo, 94.4 percent of all readings from the device were accurate in the 20 adult type 1s and type 2s who tested it. (“Benign errors”-readings that, although inaccurate, did not endanger users in any way-accounted for another 2.5 percent of all readings.) With blood glucose measurements ranging from 42 to 333 mg/dL, 96.8 percent of readings were within plus or minus two mg/dL.
Lilly/Boehringer reported that two phase 2 trials of its investigational basal insulin analog, currently labeled LY2605541, have shown positive results in glycemic control with two groups:
• A trial with type 1 patients has shown LY2605541 to be superior to insulin glargine in controlling blood glucose levels.
• A trial with type 2 patients has shown that LY2605541 in combination with insulin glargine can achieve the same results as stand-alone LY2605541 did with the type 1 group. The companies say that the new insulin appears to work “preferentially” in the liver, a characteristic that makes it more like the body’s own naturally produced insulin. LY2605541 now moves to a phase 3 trial.
Type 1 Therapies
Hylenex® recombinant (hyaluronidase human injection) from Halozyme Therapeutics modifies tissue permeability, making tissue under the skin at an insulin infusion site better able to absorb the insulin and deliver it more quickly to the circulatory system.
Halozyme reports that in phase 4 studies, immediately after infusion set sites were changed every three days, a dose of Hylenex or placebo was injected through the infusion cannula. The product reportedly produced faster insulin absorption and significantly improved post-meal glucose control. Hylenex is currently available to US healthcare providers.
Cebix Inc. reported that its once-weekly C-peptide replacement therapy for type 1 patients, ErsattaTM, was well tolerated in a randomized study involving 30 patients. Cebix is developing the therapy, a long-acting form of human C-peptide, to treat diabetic peripheral neuropathy.
Previous studies have shown that C-peptide replacement therapy in type 1 patients increases nerve blood flow and lessens peripheral and autonomic neuropathy. However, naturally occurring C-peptide has a half life of one hour, compared to Ersatta’s six- to seven-day half life.
Cebix is now testing Ersatta in a phase 3 clinical trial involving 40 type 1 patients with neuropathy. The FDA has fast-tracked the drug to accelerate its marketplace arrival.
Type 2 Therapies
Along with SGLT inhibitors and bariatric surgery, several other drugs for the treatment of type 2 diabetes were the topic of papers presented at the sessions:
• Halozyme Therapeutics reported positive data from a clinical trial that paired its rHuPH20 (human hyaluronidase enzyme) with rapid analog insulin. The enzyme accelerates the absorption and action of prandial insulins taken at meals. In the trial, rHuPH20 was combined with rapid analog insulins lispro or aspart and then compared to lispro alone. Results showed a 61 percent increase in the proportion of type 2 patients who achieved a post-prandial glucose target of less than 140 mg/dL at least two-thirds of the time compared to the lispro-only patient group.
• Amylin presented four-year data for its recently introduced Bydureon (once-weekly injectible exenatide), which showed that the drug demonstrated significant and sustained glycemic control over a four-year test period, provided greater glucose control, weight loss, and lowered risk of hypoglycemia than once- or twice-daily Levemir, and improved fasting glucose, glycemic control and weight loss regardless of type 2 patients’ baseline weight at the start of treatment.
• Merck reported that studies show that type 2 patients 65 years and older treated with 100 mg of Januvia (sitagliptin, a DPP-4 inhibitor) achieved similar blood sugar reductions as patients taking a sulfonylurea, with “significantly less” hypoglycemia.
• Eli Lilly and Boehringer Ingelheim presented data from two phase 3 studies and a post-hoc analysis that demonstrate the effectiveness of their once-daily oral medication, Tradjenta (linagliptin, a DPP-4 inhibitor). Among the studies’ conclusions were that Tradjenta is safe and effective as a therapy for glycemic control, either alone or in combination with metformin or pioglitazone.