‘Soliqua is considered an initial intensification therapy for patients with hard-to-control blood glucose’

According to data from the Korean Diabetes Association, last year's prevalence of diabetes in Korea reached one in seven adults aged 30 and older (15.5 percent). The prevalence of prediabetes is also quite high at 41.1 percent. However, patients' blood glucose control rates remain low.

Only 32.4 percent of patients achieved a target HbA1c level below 6.5 percent, and 60.6 percent achieved a level below 7 percent. Conversely, 16 percent had HbA1c levels of 8 percent or higher, indicating they require intensive treatment. The number of patients on triple or more drug regimens is also rapidly increasing.

"As the patients who have had the disease since the 2000s age, the burden of complications is growing,” said Professor Rhee Eun-jung of the Endocrinology Department at Kangbuk Samsung Hospital. “Conditions that an aging society faces, such as dialysis, dementia, and Parkinson's disease, can ultimately stem from failed diabetes management. Therefore, preparing for a super-aged society must start with diabetes prevention and treatment.”

Professor Rhee cited two main reasons for the difficulty in controlling diabetes.

First is low patient compliance. Even when advised to add medication or switch to injectables, patients often refuse. Second is clinical inertia in the treatment setting. There is a tendency to delay intensifying treatment due to the burden of selecting medications and explaining side effects. Persuading patients to switch from oral to injectable medications is particularly challenging.

“Currently, only about 6 percent of patients receive insulin injections, but the actual number of patients who need it is likely much higher,” Rhee said. “Reducing clinical inertia that delays treatment intensification is key to preventing complications.”

Failure to achieve early glycemic control not only increases the risk of complications but also raises the probability of treatment failure. Previous studies, including the UKPDS and VERIFY, have also demonstrated that early combination therapy reduces treatment failure rates and preserves pancreatic function.

“Prolonged high blood sugar causes ‘glucotoxicity,’ which damages the pancreas,” Professor Rhee explained. “The key is not to use strong medications too quickly, but to implement intensified treatment at the right time to protect the pancreas.”

Indeed, many patients arriving at university hospitals are already in severe stages of the disease.

“We clearly set a target blood glucose achievement deadline for patients and document in their charts that if they fail, we will add medication or start insulin,” Rhee said. “Preventing complications is difficult unless the physician builds trust with the patient and persuades them.

Rhee described her as a “strict doctor,” adding, “Ultimately, patients come to understand this process benefits them.”

Against this backdrop, a treatment option gaining attention in clinical practice is the fixed-ratio combination (FRC). FRC combines basal insulin and a GLP-1 receptor agonist in a single injection, thereby simultaneously controlling both fasting and postprandial blood glucose levels. In contrast, premixed insulin combines basal insulin with rapid-acting insulin, posing a greater risk of hypoglycemia and weight gain.

FRC particularly excels at controlling “residual hyperglycemia”—where fasting blood glucose is normal but HbA1c remains elevated. Professor Rhee stated, “In such cases, FRC is clearly advantageous over using basal insulin alone.”

The Soli-D study presented at the 2024 ADA compared Soliqua (FRC) with premix in Chinese patients and demonstrated superiority of FRC in both HbA1c reduction (-2.0 percent vs. -1.7 percent for premix) and target blood glucose attainment rate (72.5 percent vs. 59.8 percent). Weight decreased in the FRC group but increased in the premix group, and the incidence of hypoglycemia was also lower with FRC.

Separately, a network meta-analysis presented at this year's ADA also showed similar results. There was approximately a 0.4 percent difference in HbA1c improvement, with an average weight change of 1.5 kg and lower insulin usage in the FRC group.

"This data supports the clinical efficacy of FRC and encourages active consideration of FRC over premix in real-world practice,” Rhee said, assessing their effectiveness.

The professor shared a memorable case involving a woman in her 40s previously treated with multiple daily insulin injections (MDI). Her weight had been steadily increasing, causing significant psychological distress. After switching to Soliqua, her weight decreased, blood glucose control improved, and her motivation for lifestyle management increased.

Another older adult in her 70s also experienced significantly improved treatment outcomes after switching from premix to FRC, with reduced weight gain and hypoglycemia burden.

However, the use of FRC formulations still faces many restrictions. Current reimbursement criteria for Soliqua only permit its use sequentially after oral agents, followed by basal insulin or GLP-1 monotherapy, and then FRC. Professor Rhee stated, “Insurance reimbursement criteria must be expanded more flexibly,” adding, “Combination drugs integrating GLP-1 agents—which have proven cardiovascular disease prevention effects—with insulin should be used without restrictions.”

She also emphasized the role of primary care providers in diabetes treatment. “Delays in convincing patients to intensify treatment increase the risk of complications,” Rhee said. “FRC agents like Soliqua should be actively used, providing patients with sufficient education and psychological support.”

In conclusion, Professor Rhee reiterated the critical importance of lifestyle management. “Blood sugar is difficult to self-monitor because it causes no pain,” she explained, using the analogy that “the patient is both the protagonist and director of their own film, while the doctor is merely a supporting actor.”

She emphasized patients’ compliance, saying, “Habit formation at the time of initial diagnosis shapes the rest of one's life,” and concluding that “lifestyle management is more crucial than medication use.”