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  1. Medical Information Right
  2. Obesity Right
  3. Zepbound (tirzepatide) injection Right
  4. Do antidrug antibodies (ADA) affect the pharmacokinetics, efficacy, or safety of ZEPBOUND® (tirzepatide)?
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Zepbound ® (tirzepatide) injection

2.5 mg/ 5 mg/ 7.5 mg/ 10 mg/ 12.5 mg/ 15 mg

Full Prescribing Information

This information is provided in response to your request. Resources may contain information about doses, uses, formulations and populations different from product labeling. See Prescribing Information above, if applicable.

Do antidrug antibodies (ADA) affect the pharmacokinetics, efficacy, or safety of ZEPBOUND® (tirzepatide)?

No clinically significant effect of ADA on the PK or effectiveness of tirzepatide has been identified. There were more hypersensitivity or injection site reactions in tirzepatide-treated patients who developed ADA compared with those who did not.

US_cFAQ_TZP037B_Z_ANTIDRUG_ANTIBODIES_CWM

See important safety information, including boxed warning, in the attached prescribing information.

Antidrug Antibodies in Phase 3 Studies for Obesity or Overweight

The observed incidence of anti-drug antibodies (ADA) is highly dependent on the sensitivity and specificity of the assay used. Differences in assay methods preclude meaningful comparisons of the incidence of anti-drug antibodies in the studies described below with the incidence of anti-drug antibodies in other studies.1

The incidence of ADA to tirzepatide was evaluated in adult patients with overweight or obesity, or with obstructive sleep apnea (OSA) and obesity, in clinical studies lasting 52 weeks or longer. Anti-tirzepatide antibodies were detected in 64.5% (1591/2467) of tirzepatide-treated patients in weight reduction clinical studies SURMOUNT-1 and SURMOUNT-2.1

Table 1. Incidence of Anti-Tirzepatide Antibodies in Clinical Studies for Weight Reduction1

Antibody Category

SURMOUNT-1 and -2

Anti-tirzepatide antibodies

64.5% (1,591/2,467)

Antibodies cross-reactive to native GIP

40%

Antibodies cross-reactive to native GLP-1

16.5%

Neutralizing antibodies against tirzepatide activity on the GIP receptor

2.8%

Neutralizing antibodies against tirzepatide activity on the GLP-1 receptor

2.7%

Neutralizing antibodies against native GIP

0.8%

Neutralizing antibodies against native GLP-1

0.1%

Abbreviations: GIP = glucose-dependent insulinotropic polypeptide; GLP-1 = glucagon-like peptide.

No clinically significant effect of anti-tirzepatide antibodies on the pharmacokinetics or effectiveness of tirzepatide has been identified.1

More tirzepatide-treated patients who developed anti-tirzepatide antibodies experienced hypersensitivity reactions or injection site reactions than those who did not develop these antibodies. See Table 2 for incidence from a pool of SURMOUNT-1 and -2 studies.1

Table 2. Hypersensitivity Reactions and Injection Site Reactions by Anti-Tirzepatide Antibody Status1

Adverse Reaction

Patients With Anti-Tirzepatide Antibodies

Patients Without Anti-Tirzepatide Antibodies

Hypersensitivity reactions

6.2%

3%

Injection site reactions

11.3%

1%

Enclosed Prescribing Information

ZEPBOUND® (tirzepatide) Injection, for subcutaneous use, Lilly

Reference

  1. Zepbound [package insert]. Indianapolis, IN: Eli Lilly and Company; 2026.

Date of Last Review: September 15, 2026

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