SURPASS-CN-INS

Study record

Population

Adults with type 2 diabetes in China receiving daily insulin glargine, alone or with metformin with or without an SGLT2 inhibitor. Of 257 randomized and treated participants, two inadvertently enrolled participants were excluded from efficacy analyses, leaving 255; safety retained all 257.

Read source · Abstract-level extractionPrimary abstract — Methods and Findings

Formulation

Investigational tirzepatide single-dose pen and marketed insulin glargine prefilled pen. The comparator used tirzepatide-matched placebo; this is not evidence for compounded preparations.

Read source · Study protocolProtocol section 6.1.4, printed page 45; registry treatment groups

Route

Subcutaneous tirzepatide or matched placebo once weekly, added to daily insulin glargine.

Read source · Registry resultsPosted treatment-group descriptions

Dose & frequency

Maintenance assignments were 5, 10 or 15 mg tirzepatide weekly, starting at 2.5 mg and increasing by 2.5 mg every four weeks. All groups continued basal insulin. The protocol reduced glargine by 20% within seven days for baseline HbA1c ≤8%, followed by a four-week stabilization period with safety exceptions and subsequent monitored titration. This was a supervised trial regimen, not personal dosing advice.

Read source · Study protocolRegistry treatment groups; protocol section 6.1.3, printed page 45

Study design

Double-blind, placebo-controlled 1:1:1:1 randomized trial, stratified by HbA1c and SGLT2 inhibitor use. Efficacy and safety populations differed; the study tests adding tirzepatide to insulin, not substituting it for insulin.

Read source · Abstract-level extractionPrimary abstract — Methods and Findings

Duration

40 weeks of treatment; registry adverse-event reporting extends through week 44.

Read source · Registry resultsPosted treatment descriptions and adverse-event time frame

Reported findings

At week 40, registry HbA1c changes for 10 and 15 mg versus placebo were −26.1 and −25.9 versus −9.96 mmol/mol; posted outcome denominators were 57, 55 and 58. The 5 mg secondary outcome was −23.0 mmol/mol (n=62). MMRM excluded data after permanent study-drug discontinuation or rescue and excluded inadvertent enrollment. These outcome denominators are not the randomized arm sizes.

Read source · Registry resultsPrimary and secondary HbA1c outcomes: units, population descriptions, denominators and least-squares means

Adverse events

Registry serious-event counts for 5/10/15 mg versus placebo were 8/65, 5/65, 8/63 versus 7/64; one death was reported in the 5 mg group. These are all-cause observations, not proof of treatment causation. Nonserious-event tables use a 5% reporting threshold, so absence from that listing does not establish no event. Full publication/registry safety reconciliation remains incomplete.

Inspect extraction gap · Registry resultsAdverse events module — event-group totals, threshold and time frame

Monitoring

The protocol required twice-weekly insulin-dose assessments during stabilization, then weekly assessments over 36 additional weeks. Site staff reviewed adjustments and provided further training when needed. Office visits were weekly or every other week initially, then every four to eight weeks. This describes planned supervision, not a personal monitoring schedule.

Read source · Study protocolSection 6.1.3, printed page 45; visually verified