Malnutrition in older adults is a significant public health concern.
Age-related changes in appetite, weight loss, and nutritional deficiencies are common in elderly people and associated with physical decline and reduced quality of life.1 Malnutrition may also increase older patients’ risk of serious illness or infection, prolonged recovery, and extended hospitalization.2 There remains a critical unmet need for pharmacologic treatments for malnutrition in older populations.
Pfizer C4541011 is a phase 1b clinical trial to evaluate a potential treatment for malnutrition in older adults. This clinical trial will assess the safety, tolerability, and pharmacodynamic effect of an oral study medicine compared to placebo in people 60 to <90 years of age, including those at risk of malnutrition.
Who can participate?
This clinical trial is enrolling participants who are generally healthy or at risk of malnutrition and meet the requirements below:
60 to <90 years of age
Weigh ≥40 kg and have a Body Mass Index (BMI) ≤25 kg/m2
Are able to walk and live independently (or with a caregiver) in a community (not in a hospital, hospice, palliative care, nursing home, or hostel)
Have adequate access to food
Additional requirements apply. Only Principal Investigators can determine eligibility.
About the clinical trial
This clinical trial includes up to a 4-week screening period, a 2-week pre-treatment period, a 16-week treatment period, and a 4-week follow-up period.
Eligible participants will be randomized 1:1 to receive the study medicine or placebo twice daily for 16 weeks. Participants will also be provided wearable digital devices to monitor physical activity, gait, blood pressure, and pulse rate at designated intervals.
Participants will be enrolled for up to 26 weeks and will need to attend at least 9 in-person visits and 11 telehealth visits. Visits will include physical and neurological exams, blood draws, ECGs, MRIs, and other assessments.
There is no cost to participate, and health insurance is not required. [Participants will receive reimbursement for trial-related expenses such as travel, parking, and meals.]
About the study medicine
The study medicine (PF-07258669) is a small molecule antagonist of melanocortin-4 receptor (MC4R), which plays a key role in the regulation of appetite and body weight.3 Pre-clinical and clinical data suggests that antagonism of MC4R may increase appetite, food intake, and body weight in patients with unintended weight loss.
In previous phase 1 clinical trials (C4541001, C4541003), oral dosing of PF-07258669 in healthy adults was generally considered safe and well tolerated.4,5 Preliminary results of an ongoing phase 1 clinical trial (C4541012) indicate that treatment with PF-07258669 was safe and well tolerated with no severe adverse events.6
PF-07258669 is investigational and has not been approved by any health authority.
Get started
Answer a 2-minute questionnaire and speak to a study representative.
A first step as you consider connecting with a Principal Investigator is to answer a 2-minute online questionnaire about your interest and willingness to be contacted. If your answers show the study might be a good fit for you and your patient, you may choose to have your contact information shared with a study clinic that you select for further discussion.
Get connected.
Your answers to these questions will only be linked to you if your responses indicate that you would like to be connected with a Principal Investigator and you choose to share your contact information with the study clinic. Pfizer study team members and our partners will have access to reports containing aggregated data that will not be directly linked back to you. Only the study staff can determine if your patient meets the study’s eligibility criteria and is able to enroll in the study.
References
1. Tomasiewicz A, Polański J, Tański W. Advancing the Understanding of Malnutrition in the Elderly Population: Current Insights and Future Directions. Nutrients. 2024;16(15):2502. Published 2024 Jul 31. doi:10.3390/nu16152502
2. Norman K, Haß U, Pirlich M. Malnutrition in Older Adults-Recent Advances and Remaining Challenges. Nutrients. 2021;13(8):2764. Published 2021 Aug 12. doi:10.3390/nu13082764
3. Kuhnen P, Krude H, Biebermann H. Melanocortin-4 Receptor Signaling: Importance for Weight Regulation and Obesity Treatment. Trends Mol Med. 2019;25(2):136-48.
4. A Study of Single Ascending Doses of PF-07258669 in Healthy Adult Participants. ClinicalTrials.gov identifier: NCT04628793. Updated February 21, 2024. Accessed May 14, 2025. https://clinicaltrials.gov/study/NCT04628793
5. A Study of PF-07258669 In Healthy Adult Participants. ClinicalTrials.gov identifier: NCT05113940. Updated October 21, 2024. Accessed May 14, 2025. https://clinicaltrials.gov/ study/NCT05113940
6. A Study to Learn if the Study Medicine Called Itraconazole and if Food Changes How the Body Processes the Other Study Medicine Called PF 07258669 in Older Adults or Healthy Adults. ClinicalTrials.gov identifier: NCT06706869. Updated March 7, 2025. Accessed May 14, 2025. https://clinicaltrials.gov/study/NCT06706869