The Fate of Taspoglutide, a Weekly GLP-1 Receptor Agonist, Versus Twice-Daily Exenatide for Type 2 Diabetes

OBJECTIVE Taspoglutide is a long-acting glucagon-like peptide 1 receptor agonist developed for treatment of type 2 diabetes. The efficacy and safety of once-weekly taspoglutide was compared with twice-daily exenatide. RESEARCH DESIGN AND METHODS Overweight adults with inadequately controlled type 2 diabetes on metformin ± a thiazolidinedione were randomized to subcutaneous taspoglutide 10 mg weekly (n = 399), taspoglutide 20 mg weekly (n = 398), or exenatide 10 µg twice daily (n = 392) in an open-label, multicenter trial. The primary end point was change in HbA1c after 24 weeks. RESULTS Mean baseline HbA1c was 8.1%. Both doses of taspoglutide reduced HbA1c significantly more than exenatide (taspoglutide 10 mg: –1.24% [SE 0.09], difference –0.26, 95% CI –0.37 to –0.15, P < 0.0001; taspoglutide 20 mg: –1.31% [0.08], difference –0.33, –0.44 to –0.22, P < 0.0001; exenatide: –0.98% [0.08]). Both taspoglutide doses reduced fasting plasma glucose significantly more than exenatide. Taspoglutide reduced body weight (taspoglutide 10 mg, –1.6 kg; taspoglutide 20 mg, –2.3 kg) as did exenatide (–2.3 kg), which was greater than with taspoglutide 10 mg (P < 0.05). HbA1c and weight effects were maintained after 52 weeks. More adverse events with taspoglutide 10 and 20 mg than exenatide developed over time (nausea in 53, 59, and 35% and vomiting in 33, 37, and 16%, respectively). Allergic and injection-site reactions were more common with taspoglutide. Discontinuations were greater with taspoglutide. Antitaspoglutide antibodies were detected in 49% of patients. CONCLUSIONS Once-weekly taspoglutide demonstrated greater glycemic control than twice-daily exenatide with comparable weight loss, but with unacceptable levels of nausea/vomiting, injection-site reactions, and systemic allergic reactions.