A Continuation Study of Tilrekimig in Adults With Moderate-to-Severe Long-Term Breathing Difficulty, Known by the Medical Term of Chronic Obstructive Pulmonary Disease (COPD) to Learn About This Medicine When Used for a Long Period of Time

A PHASE 3, MULTICENTER, OPEN-LABEL EXTENSION STUDY TO EVALUATE LONG-TERM SAFETY, TOLERABILITY, AND EFFICACY OF TILREKIMIG IN ADULT PARTICIPANTS WITH MODERATE-TO-SEVERE CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)

A Continuation Study of Tilrekimig in Adults with Moderate-to-Severe Long-Term Breathing Difficulty, Known by the Medical Term of Chronic Obstructive Pulmonary Disease (COPD) to Learn About this Medicine when Used for a Long Period of Time.

Study Overview

• Status: Not yet recruiting
• Conditions: Moderate to Severe Chronic Obstructive Pulmonary Disease
• Intervention / Treatment: Drug: Tilrekimig

Detailed Description

C4531015 is a multicenter, open-label extension study designed to evaluate the longer-term safety and tolerability of tilrekimig in eligible participants with chronic obstructive pulmonary disease (COPD) who have participated in and completed the applicable requirements of the parent study, C4531031.

Participants who complete the protocol-defined parent-study period may be considered for enrollment in C4531015. Before entering the extension study, participants must provide informed consent, satisfy all C4531015 eligibility criteria, and be considered appropriate for continued study treatment by the investigator. Participation in C4531031 does not automatically establish eligibility for the extension study.

All enrolled participants will receive open-label tilrekimig according to the dose, route of administration, and treatment schedule specified in the C4531015 protocol. Participants may continue protocol-permitted background COPD maintenance therapy. Use of concomitant and rescue medications will be managed according to the protocol.

The study will primarily characterize the safety and tolerability of longer-term exposure to tilrekimig. Safety monitoring will include the collection of adverse events (AEs), serious adverse events (SAEs), adverse events leading to treatment interruption or discontinuation, and other protocol-defined safety events. Participants will also undergo clinical laboratory testing, vital-sign assessments, physical examinations, and other safety evaluations at scheduled study visits.

Additional protocol-defined assessments may be conducted to characterize COPD-related clinical outcomes and the effects of continued treatment. These may include evaluation of COPD exacerbations, respiratory symptoms, lung function, health status, participant-reported outcomes (PROs), healthcare resource utilization, pharmacokinetics (PK), immunogenicity, biomarkers, or other exploratory measures, as applicable. These assessments are intended to provide supportive information and should not be interpreted as demonstrating that tilrekimig is safe or effective.

Participants will attend study visits according to the protocol Schedule of Activities (SoA). At these visits, investigators will assess continued eligibility, treatment adherence, changes in health status, AEs, concomitant medications, COPD-related events, and the results of required clinical and laboratory evaluations.

Participants may discontinue study intervention because of an AE, pregnancy, use of prohibited medication, lack of compliance with protocol requirements, an investigator or sponsor decision, withdrawal of consent, or another protocol-defined reason. Participants who discontinue study intervention may be asked to complete applicable early-discontinuation and safety follow-up assessments.

The study may provide eligible participants transitioning from C4531031 with continued access to investigational treatment while allowing additional safety and clinical information to be collected over a longer treatment period. Tilrekimig remains investigational, and participation in the study does not guarantee that an individual participant will experience clinical benefit.

• Study Type: Interventional
• Enrollment (Estimated): 1360
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Pfizer CT.gov Call Center; Phone Number: 1-800-718-1021; Email: ClinicalTrials.gov_Inquiries@pfizer.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

INCLUSION CRITERIA

• Participants who completed parent study C4531031.
• Individuals of childbearing potential must be willing to use a highly effective method of contraception.

EXCLUSION CRITERIA

• Ongoing safety-significant AE.
• Parent-study SAE incompatible with continued participation.
• Medical, laboratory, psychiatric, or behavioral condition that increases risk or interferes with study participation.
• Pregnancy or breastfeeding.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Tilrekimig (PF-07275315); Tilrekimig (PF-07275315) subcutaneous injection (sc)	Drug: Tilrekimig; SC injection; Other Names: PF-07275315

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Treatment-Emergent Adverse Events During Treatment Period 1 (TP1)	Number and percentage of participants with treatment-emergent adverse events. An adverse event is considered treatment-emergent if it begins or increases in severity following initiation of study intervention. Events will be summarized by severity and other protocol-defined characteristics	Up to 60 weeks
Number of Participants With Treatment-Emergent Serious Adverse Events During Treatment Period 1	Number and percentage of participants with treatment-emergent serious adverse events. Serious adverse events are events that meet one or more of the protocol-defined seriousness criteria.	Up to 60 weeks
Number of Participants With Treatment-Emergent Adverse Events Leading to Permanent Discontinuation of Study Intervention During Treatment Period 1	Number and percentage of participants with treatment-emergent adverse events that lead to permanent discontinuation of tilrekimig.	Up to 60 weeks
Number of Participants With Clinically Significant Laboratory Abnormalities During Treatment Period 1	Number and percentage of participants with protocol-defined clinical abnormalities in laboratory values and vitals signs. Laboratory assessments include protocol-required hematology and blood chemistry evaluations. Abnormal laboratory findings will be evaluated according to protocol-defined criteria and investigator assessment of clinical significance. Vital-sign assessments include blood pressure, pulse rate, respiratory rate, temperature, and oxygen saturation measured by pulse oximetry.	Up to 60 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Annualized Rate of Moderate or Severe COPD Exacerbations During Treatment Period 1	Unadjusted annualized rate of adjudicated moderate or severe exacerbations of COPD. A moderate exacerbation is an acute worsening of COPD requiring systemic corticosteroids and/or antibiotics. A severe exacerbation is an acute worsening of COPD requiring hospital admission for at least 24 hours.	52 Weeks
Annualized Rate of Severe COPD Exacerbations During Treatment Period 1	Unadjusted annualized rate of adjudicated severe COPD exacerbations. A severe COPD exacerbation is an acute worsening of COPD requiring hospital admission for at least 24 hours.	52 Weeks
Annualized Rate of COPD Exacerbations Requiring an Emergency Department Visit and/or Hospitalization During Treatment Period 1	Unadjusted annualized rate of COPD exacerbations requiring an emergency department visit and/or hospitalization.	52 Weeks
Cumulative Number of Moderate or Severe COPD Exacerbations During Treatment Period 1	Mean cumulative number of adjudicated moderate or severe COPD exacerbation events over time.	52 Weeks
Cumulative Number of Severe COPD Exacerbations During Treatment Period 1	Mean cumulative number of adjudicated severe COPD exacerbation events over time.	52 Weeks
Time to First Moderate or Severe COPD Exacerbation During Treatment Period 1	Treatment Period 1Time from initiation of C4531015 study intervention to the first adjudicated moderate or severe COPD exacerbation. The probability of an event will be estimated using the Kaplan-Meier method.	52 Weeks
Change From Parent-Study Baseline in Pre- and Post-Bronchodilator Lung Function During Treatment Period 1	Change from the parent-study baseline at each scheduled assessment in the following spirometry parameters: pre-bronchodilator FEV1, post-bronchodilator FEV1, pre-bronchodilator FEV1/FVC ratio, and post-bronchodilator FEV1/FVC ratio. FEV1 is the forced expiratory volume in 1 second, and FVC is the forced vital capacity. Spirometry will be performed using standardized equipment and procedures. Post-bronchodilator measurements will be obtained following administration of a short-acting bronchodilator in accordance with the protocol. FEV1 will be reported in liters, and FEV1/FVC will be reported as a ratio.	52 Weeks
Change From Parent-Study Baseline in Saint George's Respiratory Questionnaire (SGRQ) Total Score During Treatment Period 1	Change from the parent-study baseline in SGRQ total score at each scheduled assessment. The SGRQ contains 50 items assessing symptoms, activity, and impacts on daily life. Total scores range from 0 to 100, with lower scores indicating better quality of life.	52 Weeks
Change From Parent-Study Baseline in COPD Assessment Test (CAT) Total Score During Treatment Period 1	Change from the parent-study baseline in CAT total score at each scheduled assessment. The CAT contains 8 items scored from 0 to 5. The total score ranges from 0 to 40, with higher scores indicating worse health.	52 Weeks
Change From Parent-Study Baseline in Weekly Use of Short-Acting Bronchodilator Medication During Treatment Period 1	Change from the parent-study baseline in weekly use of short-acting bronchodilator medication at each protocol-specified assessment. Use of the bronchodilator administered solely for post-bronchodilator spirometry is excluded.	52 Weeks
Percentage of Participants Achieving at Least a 4-Point Improvement From Parent-Study Baseline in SGRQ Total Score During Treatment Period 1	Percentage of participants classified as SGRQ responders at each scheduled assessment. A responder is a participant with an improvement of at least 4 points from the parent-study baseline in SGRQ total score. An improvement corresponds to a reduction in the total score.	52 Weeks
Percentage of Participants Achieving at Least a 2-Point Improvement From Parent-Study Baseline in CAT Total Score During Treatment Period 1	Percentage of participants classified as CAT responders at each scheduled assessment. A responder is a participant with an improvement of at least 2 points from the parent-study baseline in CAT total score. An improvement corresponds to a reduction in the total score.	52 Weeks
COPD Exacerbations in Participants With Parent-Study Baseline Blood Eosinophil Count ≥300 Cells/µL	Unadjusted annualized rate of adjudicated moderate or severe COPD exacerbations in participants with a blood eosinophil count of at least 300 cells/µL at the parent-study baseline	52 Weeks
Lung Function in Participants With Parent-Study Baseline Blood Eosinophil Count ≥300 Cells/µL	Change from parent-study baseline in pre-bronchodilator FEV1; change from parent-study baseline in post-bronchodilator FEV1 in participants with a blood eosinophil count of at least 300 cells/µL at the parent-study baseline	52 Weeks
Annualized Rate of Moderate or Severe COPD Exacerbations Through End of Study	Unadjusted annualized rate of adjudicated moderate or severe COPD exacerbations over the participant's full period of study participation.	Up to 36 months
Annualized Rate of Severe COPD Exacerbations Through End of Study	Unadjusted annualized rate of adjudicated severe COPD exacerbations over the participant's full period of study participation.	Up to 36 months
Annualized Rate of COPD Exacerbations Requiring an Emergency Department Visit and/or Hospitalization Through End of Study	Unadjusted annualized rate of COPD exacerbations requiring an emergency department visit and/or hospitalization.	Up to 36 months
Cumulative Number of Moderate or Severe COPD Exacerbations Through End of Study	Mean cumulative number of adjudicated moderate or severe COPD exacerbation events over time.	Up to 36 months
Cumulative Number of Severe COPD Exacerbations Through End of Study	Mean cumulative number of adjudicated severe COPD exacerbation events over time.	Up to 36 months
Change From Parent-Study Baseline in COPD Assessment Test total score During Treatment Period 1 in participants with Parent-Study Baseline Blood Eosinophil Count ≥300 Cells/µL	Change from parent-study baseline in CAT total score in participants with a blood eosinophil count of at least 300 cells/µL at the parent-study baseline	52 Weeks
Change From Parent-Study Baseline in Pre- and Post-Bronchodilator Lung Function Through End of Study	Change from the corresponding parent-study baseline at each protocol-specified assessment in the following spirometry parameters: pre-bronchodilator FEV1, post-bronchodilator FEV1, pre-bronchodilator FEV1/FVC ratio, and post-bronchodilator FEV1/FVC ratio. FEV1 is forced expiratory volume in 1 second, and FVC is forced vital capacity. Spirometry will be performed using standardized equipment and procedures. Post-bronchodilator measurements will be obtained after administration of a short-acting bronchodilator in accordance with the protocol. FEV1 will be reported in liters and FEV1/FVC as a ratio.	Up to 36 months
Change From Parent-Study Baseline in SGRQ Total Score After Week 52	Change from the parent-study baseline in SGRQ total score at each scheduled assessment after Week 52 of TP1. Scores range from 0 to 100, with lower scores indicating better quality of life.	Up to 36 months
Change from the parent-study baseline in CAT total score at each scheduled assessment after Week 52 of TP1	Change from the parent-study baseline in CAT total score at each scheduled assessment after Week 52 of TP1. Scores range from 0 to 40, with higher scores indicating worse health.	Up to 36 months
Change From Parent-Study Baseline in Saint George's Respiratory Questionnaire total score Total Score During Treatment Period 1 in participants with Parent-Study Baseline Blood Eosinophil Count ≥300 Cells/µL	Change from parent-study baseline in Saint George's Respiratory Questionnaire total score in participants with a blood eosinophil count of at least 300 cells/µL at the parent-study baseline	52 Weeks
Change From Parent-Study Baseline in Weekly Use of Short-Acting Bronchodilator Medication After Week 52	Change from the parent-study baseline in weekly use of short-acting bronchodilator medication at each scheduled assessment after Week 52 of TP1.	Up to 36 months
Percentage of Participants Achieving at Least a 4-Point Improvement From Parent-Study Baseline in SGRQ Total Score After Week 52	Percentage of participants with an improvement of at least 4 points from the parent-study baseline in SGRQ total score at each scheduled assessment after Week 52.	Up to 36 months
Percentage of Participants Achieving at Least a 2-Point Improvement From Parent-Study Baseline in CAT Total Score After Week 52	Percentage of participants with an improvement of at least 2 points from the parent-study baseline in CAT total score at each scheduled assessment after Week 52.	Up to 36 months
Time to First Moderate or Severe COPD Exacerbation Through End of Study	Time from initiation of C4531015 study intervention to the first adjudicated moderate or severe COPD exacerbation. The probability of an event will be estimated using the Kaplan-Meier method.	Up to 36 months

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• <p>To obtain contact information for a study center near you, click here.</p>

Study record dates

Study Major Dates

• Study Start (Estimated): September 21, 2026
• Primary Completion (Estimated): May 12, 2034
• Study Completion (Estimated): May 12, 2034

Study Registration Dates

• First Submitted: September 18, 2026
• First Submitted That Met QC Criteria: September 18, 2026
• First Posted (Actual): September 24, 2026

Study Record Updates

• Last Update Posted (Actual): September 24, 2026
• Last Update Submitted That Met QC Criteria: September 18, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: COPD
• Additional Relevant MeSH Terms: Pathologic Processes; Chronic Disease; Disease Attributes; Respiratory Tract Diseases; Lung Diseases; Lung Diseases, Obstructive; Pathological Conditions, Signs and Symptoms; Pulmonary Disease, Chronic Obstructive
• Other Study ID Numbers: C4531015; 2026-528166-19-00 (Ctis)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No