A Study to Evaluate the Efficacy and Safety of CLBS16 in Subjects with Coronary Microvascular Dysfunction and Without Obstructive Coronary Artery Disease


About this study

The purpose of this study is to evaluate the effectiveness and safety of intracoronary delivery of autologous CD34+ cells (CLBS16) in subjects with coronary microvascular dysfunction (CMD) and without obstructive coronary artery disease

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Men or women age ≥ 18.
  • History of effort-induced anginal symptoms and currently experiencing angina at least 3 times per week, despite maximally tolerated doses of antianginal medications, statins, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and other medications thought to positively impact subjects with CMD.
  • Diagnosis of CMD within 180 days prior to the first screening visit based on the following thresholds: coronary flow reserve (CFR) ≤ 2.5, coronary blood flow (CBF) response to acetylcholine ≤ 50%, myocardial perfusion reserve (MPR) or myocardial flow reserve (MFR) 25.
  • *CCS class II, III, or IV chronic refractory angina as evaluated by the site.
  • No obstructive disease on coronary angiogram within 6 months prior to or during screening. The following is allowed: a coronary artery stenosis less than 40% in the left main coronary artery, or a stenosis less than 50% in any other epicardial coronary artery.
  • if subject is of childbearing potential, the subject must have a negative pregnancy test at screening and prior to mobilization and G-CSF treatment, and prior to receiving treatment. The subject agrees to employ adequate birth control measures for the duration of the study. Acceptable methods of birth control are: oral contraceptive tablets, hormonal implant device, hormonal patch, intrauterine device, diaphragm and contraceptive cream or foam, condom with spermicide, partner vasectomy, or abstinence.
  • Subject is willing and able to comply with the requirements of the protocol.
  • Any cardiovascular medical therapy must be at a stable dose for at least 30 days prior to the first screening visit and must be maintained at that dose throughout the duration of the study; cardiovascular therapy would generally include statins (unless not tolerated), ACE inhibitors, ARBs, beta blockers, calcium channel blockers, and/or ranolazine (unless ineffective or not tolerated).
  • Able to provide signed informed consent.

Exclusion Criteria:

  • Myocardial infarction within 90 days prior to consent or between consent and treatment with CLBS16.
  • Evidence of obstructive heart disease on screening angiogram or within 6 months prior to consent, including prior CABG at any time or history of PCI within 6 months prior to consent.
  • Planned PCI or CABG.
  • Diagnosis of other specific cardiac disease including:
    • aortic valve area < 1.0;
    • 3+ mitral regurgitation;
    • 3+ aortic insufficiency;
    • hypertrophic cardiomyopathy;
    • suspected or diagnosed Prinzmetal angina, or if acetylcholine provocation has been performed, significant coronary spasm as defined by more than 70% reduction in vessel diameter in response to acetylcholine;
    • severe myocardial bridging per investigator’s discretion;
    • Any anomalous coronary anatomy which could contribute to the subject’s angina.
  • LVEF < 30%.
  • Glomerular filtration rate < 30 mL/min/1.73m^2 (MDRD).
  • Subject currently uses coumadin, dabigatran, apixaban, rivaroxaban, or edoxaban or plans to use one of these agents during the time frame of the trial.
  • Subject has serious hypersensitivity or a history of adverse reaction to G-CSF or apheresis.
  • Subject has a known allergy to mouse proteins
  • Subject tests positive for human immunodeficiency virus (HIV), hepatitis B or hepatitis C.
  • Subject with chronic inflammatory disease or autoimmune disease that has had an acute exacerbation of disease within the last 6 months, or subjects that are on immunosuppressive agents or in a chronic immunosuppressive state.
  • Recent history of abuse or current abuser of alcohol or recreational drugs.
  • Subject is pregnant or lactating at the time of signing the consent.
  • Malignant neoplasm (other than adequately treated non-melanoma skin cancer or in situ cervical carcinoma) within 5 years prior to screening.
  • Subject has participated in another clinical study within 90 days prior to signing the informed consent or is scheduled to participate in another clinical study during the course of the study. Observational studies in which the subject did not receive treatment or did not undergo procedures which may compromise this study’s data integrity may be allowable following Sponsor approval.
  • History of sickle cell disease.
  • Previous treatment with a CD34+ cell-based therapy.
  • Any other condition which, in the opinion of the investigator, may preclude the subject from safe participation in the study or compromise data integrity

Eligibility last updated 10/4/21. Questions regarding updates should be directed to the study team contact.


Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status

Rochester, Minn.

Mayo Clinic principal investigator

Amir Lerman, M.D.

Closed for enrollment

More information


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