Albiglutide
GSK716155, albumin-GLP-1 fusion protein
Albiglutide was a once-weekly GLP-1 receptor agonist created by fusing a tandem GLP-1 dimer to recombinant human albumin. It was approved in the United States and European Union in 2014 but withdrawn from all markets by July 2018 for commercial reasons. Its cardiovascular outcomes trial, published after withdrawal, showed a clear reduction in major adverse cardiovascular events, making it an unusual case of a medicine whose best evidence arrived after it had been discontinued.
Mechanism
Albiglutide activates the GLP-1 receptor through the standard incretin pathway: Gs coupling, cyclic AMP generation, glucose-dependent insulin secretion, glucagon suppression, delayed gastric emptying and reduced appetite. The molecular design differs from every other agent in the class. Rather than acylating a peptide to bind albumin non-covalently, as liraglutide and semaglutide do, albiglutide is genetically fused to albumin. Two copies of a DPP-4-resistant GLP-1 analogue sit in tandem at the amino terminus of a full-length recombinant human albumin molecule, giving a single expressed protein of roughly 73 kDa.
That size has consequences. Renal filtration is impossible, so clearance depends on general protein catabolism and albumin's own long circulatory lifespan mediated by neonatal Fc receptor recycling. It also restricts passage across the blood-brain barrier and into deep tissue compartments, and this is the leading explanation for albiglutide's comparatively weak central effects: it produced notably less nausea than other GLP-1 receptor agonists but also markedly less weight loss, typically around 1 kg or less in trials. In pharmacological terms albiglutide traded central potency for tolerability, and in the head-to-head comparison against liraglutide that trade proved unfavourable.
What the research shows
The HARMONY programme demonstrated consistent but modest glycaemic efficacy. HARMONY 3 followed roughly 1,012 patients for 104 weeks and showed albiglutide superior to placebo, sitagliptin and glimepiride on HbA1c. HARMONY 4 randomised 779 patients and established non-inferiority to insulin glargine over 52 weeks with weight loss instead of weight gain. HARMONY 2 confirmed monotherapy efficacy in 309 patients over 52 weeks. The negative result that shaped the drug's fate was HARMONY 7: in 841 patients across 162 sites, albiglutide failed to meet non-inferiority against liraglutide 1.8 mg daily, with HbA1c reductions of 0.78 versus 0.99 percentage points, and produced considerably less weight loss. Injection-site reactions were substantially more frequent with albiglutide, while gastrointestinal effects were less frequent.
Harmony Outcomes, published in 2018 after the withdrawal decision, randomised 9,463 people with type 2 diabetes and established cardiovascular disease and followed them for a median of only 1.6 years. Major adverse cardiovascular events occurred in 7% of albiglutide recipients versus 9% on placebo, a hazard ratio of 0.78 (95% CI 0.68-0.90), driven principally by a reduction in myocardial infarction. This is one of the largest relative risk reductions reported for any GLP-1 receptor agonist, achieved over the shortest follow-up, and it is unusual in having been observed in a drug that produced almost no weight loss. That dissociation is often cited as evidence that GLP-1 receptor cardiovascular benefit is not simply a consequence of weight reduction, though a single trial cannot settle the question.
Evidence assessment
High-quality evidence
Albiglutide held approved labelling in both the United States and European Union and was supported by the multi-trial HARMONY phase 3 programme plus Harmony Outcomes, a 9,463-participant cardiovascular outcomes trial. The evidence tier reflects the quality and replication of the trial data, not current availability; the product has not been marketed since 2018. All five cited studies were individually verified, and two sample sizes in the draft were corrected.
Tiers are applied consistently across the library and re-checked when new trials read out. Read the grading method.
Key studies
Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial Preclinical only
Major adverse cardiovascular events occurred in 7% versus 9% on placebo, hazard ratio 0.78 (95% CI 0.68-0.90), driven mainly by reduced myocardial infarction. The benefit emerged despite negligible weight loss.
Once-weekly albiglutide versus once-daily liraglutide in patients with type 2 diabetes inadequately controlled on oral drugs (HARMONY 7): a randomised, open-label, multicentre, non-inferiority phase 3 study Preclinical only
Albiglutide did not meet the non-inferiority margin against liraglutide 1.8 mg (HbA1c reductions 0.78 versus 0.99 percentage points) and produced less weight loss, though with fewer gastrointestinal effects and more injection-site reactions.
HARMONY 3: 104-week randomized, double-blind, placebo- and active-controlled trial assessing the efficacy and safety of albiglutide compared with placebo, sitagliptin, and glimepiride in patients with type 2 diabetes taking metformin Preclinical only
Albiglutide was superior to placebo, sitagliptin and glimepiride for HbA1c reduction at two years, with weight loss relative to glimepiride and less hypoglycaemia.
HARMONY 4: randomised clinical trial comparing once-weekly albiglutide and insulin glargine in patients with type 2 diabetes inadequately controlled with metformin with or without sulfonylurea Preclinical only
Albiglutide was non-inferior to insulin glargine on HbA1c, with weight loss rather than the weight gain seen with glargine, and less hypoglycaemia.
Efficacy and safety of once-weekly GLP-1 receptor agonist albiglutide (HARMONY 2): 52 week primary endpoint results from a randomised, placebo-controlled trial in patients with type 2 diabetes mellitus inadequately controlled with diet and exercise Preclinical only
Albiglutide monotherapy significantly reduced HbA1c versus placebo at 52 weeks, with a low rate of hypoglycaemia but minimal weight change.
Safety
Gastrointestinal effects were milder than for most GLP-1 receptor agonists, consistent with limited central nervous system penetration, but diarrhoea and nausea remained common. Injection-site reactions, including erythema, rash and induration, were distinctly more frequent than with peptide-based agonists and were a leading cause of discontinuation, reflecting the large fusion-protein construct. The US label carried the class boxed warning for thyroid C-cell tumours based on rodent data. Acute pancreatitis was reported and listed as a warning. Hypoglycaemia was uncommon with albiglutide alone but frequent alongside sulfonylureas or insulin. Immunogenicity was measurable but did not appear to attenuate efficacy meaningfully. No renal dose adjustment was required. Because the product has not been marketed since 2018, long-term post-marketing safety data are limited to the trial period.
Regulatory status
| Jurisdiction | Status |
|---|---|
| United Kingdom | Authorised across the European Union from March 2014, with a corresponding UK licence at the time. The marketing authorisation was withdrawn at the holder's request during 2018 and the product was removed from all European markets. It is not obtainable in the UK and has no current MHRA authorisation. |
| United States | Approved by the FDA in April 2014 as an adjunct to diet and exercise for glycaemic control in adults with type 2 diabetes. The manufacturer announced withdrawal in 2017 and completed removal from the market in July 2018, stating explicitly that the decision reflected limited commercial prospects rather than any safety or efficacy concern. The product is no longer available and no generic or biosimilar version exists. |
| WADA (sport) | Not prohibited. Albiglutide never appeared on the WADA Prohibited List, and GLP-1 receptor agonists remain unlisted as a class. |
Questions
For commercial reasons. It produced smaller reductions in HbA1c and body weight than liraglutide and other competitors, failed a head-to-head non-inferiority test against liraglutide, and caused more injection-site reactions. The manufacturer stated the withdrawal was not related to any safety or efficacy concern.
Harmony Outcomes reported in October 2018, after the commercial withdrawal decision had already been taken and executed. Reintroducing a discontinued biologic requires re-establishing manufacturing and regulatory infrastructure, which was not judged commercially viable against competitors with both cardiovascular benefit and far superior weight loss.
Its roughly 73 kDa albumin fusion is too large to reach appetite-regulating centres efficiently. Weight loss in trials was typically around 1 kg or less. The same property explains its unusually low rate of nausea, since that effect is also centrally mediated.
It is a useful natural experiment. Albiglutide produced a 22% relative reduction in major adverse cardiovascular events while causing almost no weight loss, which argues that cardiovascular benefit in this class is not simply a downstream consequence of reduced body weight. One trial cannot prove the point, but it is hard to explain away.