6.1Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Linagliptin/Metformin The safety of concomitantly administered linagliptin (daily dosage 5 mg) and metformin (mean daily dosage of approximately 1,800 mg) has been evaluated in 2,816 patients with type 2 diabetes mellitus treated for ≥12 weeks in clinical trials.
Three placebo-controlled trials with linagliptin + metformin were conducted: 2 studies were 24 weeks in duration, 1 trial was 12 weeks in duration. In the 3 placebo-controlled clinical studies, adverse reactions which occurred in ≥5% of patients receiving linagliptin + metformin (n=875) and were more common than in patients given placebo+ metformin (n=539) included nasopharyngitis (5.7% vs 4.3%). In a 24-week factorial design trial, adverse reactions reported in ≥5% of patients receiving linagliptin + metformin and were more common than in patients given placebo are shown in Table 1.
Table 1 Adverse Reactions Reported in ≥5% of Patients Treated with Linagliptin + Metformin and Greater than with Placebo in a 24-week Factorial-Design Trial Adverse Reactions Placebo (%) n =72 Li n a g li pt in M o n o th er a py (%) n =142 M e tf or m i n M o n o th er a py (%) n =291 C o m b i n a t io n of Li n a g li pt i n with Metformin(%) n =286 Nasopharyngitis 1.4 5.6 2.7
6.3 Other adverse reactions reported in clinical studies with treatment of linagliptin + metformin were hypersensitivity (e.g., urticaria, angioedema, or bronchial hyperreactivity), cough, decreased appetite, nausea, vomiting, pruritus, and pancreatitis. Linagliptin Adverse reactions reported in ≥2% of patients treated with linagliptin 5 mg and more commonly than in patients treated with placebo included: nasopharyngitis (7% vs 6.1%), diarrhea (3.3% vs 3%), and cough (2.1% vs 1.4%).
Rates for other adverse reactions for linagliptin 5 mg vs placebo when linagliptin was used in combination with specific anti-diabetic agents were: urinary tract infection (3.1% vs 0%) and hypertriglyceridemia (2.4% vs 0%) when linagliptin was used as add-on to sulfonylurea; hyperlipidemia (2.7% vs 0.8%) and weight increased (2.3% vs 0.8%) when linagliptin was used as add-on to pioglitazone; and constipation (2.1% vs 1%) when linagliptin was used as add-on to basal insulin therapy.
Other adverse reactions reported in clinical studies with treatment of linagliptin monotherapy were hypersensitivity (e.g., urticaria, angioedema, localized skin exfoliation, or bronchial hyperreactivity) and myalgia. In the clinical trial program, pancreatitis was reported in 15.2 cases per 10,000 patient year exposure while being treated with linagliptin compared with 3.7 cases per 10,000 patient year exposure while being treated with comparator (placebo and active comparator, sulfonylurea).
Three additional cases of pancreatitis were reported following the last administered dose of linagliptin. Metformin The most common (>5%) adverse reactions due to initiation of metformin therapy are diarrhea, nausea/vomiting, flatulence, abdominal discomfort, indigestion, asthenia, and headache. Other Adverse Reactions Hypoglycemia Linagliptin/Metformin In a 24-week factorial design trial, hypoglycemia was reported in 4 (1.4%) of 286 subjects treated with linagliptin + metformin, 6 (2.1%) of 291 subjects treated with metformin, and 1 (1.4%) of 72 subjects treated with placebo.
The incidence of hypoglycemia with plasma glucose <54 mg/dL was 8.1% in the linagliptin group (N=792) compared to 5.3% in the placebo group (N=263) when administered in combination with metformin and sulfonylurea in a 24-week trial. Linagliptin The incidence of severe hypoglycemia (requiring assistance) was 1.7% in the linagliptin group (N=631) compared to 1.1% in the placebo group (N=630) when administered in combination with basal insulin in a 52-week trial.
Laboratory Test Abnormalities in Clinical Trials of Linagliptin or Metformin Linagliptin Increase in Uric Acid: Changes in laboratory values that occurred more frequently in the linagliptin group and ≥1% more than in the placebo group were increases in uric acid (1.3% in the placebo group, 2.7% in the linagliptin group). Increase in Lipase: In a placebo-controlled clinical trial with linagliptin in type 2 diabetes mellitus patients with micro- or macroalbuminuria, a mean increase of 30% in lipase concentrations from baseline to 24 weeks was observed in the linagliptin arm compared to a mean decrease of 2% in the placebo arm.
Lipase levels above 3 times upper limit of normal were seen in 8.2% compared to 1.7% patients in the linagliptin and placebo arms, respectively. Increase in Amylase: In a cardiovascular safety trial comparing linagliptin versus glimepiride in patients with type 2 diabetes mellitus, amylase levels above 3 times upper limit of normal were seen in 1% compared to 0.5% of patients in the linagliptin and glimepiride arms, respectively.
The clinical significance of elevations in lipase and amylase with linagliptin is unknown in the absence of potential signs and symptoms of pancreatitis [see Warnings and Precautions (5.2 )]. Metformin Decrease in Vitamin B 12 : In metformin clinical trials of 29-week duration, a decrease to subnormal levels of previously normal serum vitamin B 12 levels was observed in approximately 7% of patients .
