Inclusion Criteria:

• Men or women age 18 years or older.
• History of effort-induced anginal symptoms and currently experiencing angina at least 3 times per week.
• No obstructive disease on coronary angiogram within 6 months prior to which includes any of the following:
  • No obstructive coronary artery disease defined as a coronary artery stenosis less than 40% in the left main coronary artery, or a stenosis 20% or greater but less than 50% in any other epicardial coronary artery;
  • Coronary flow reserve to intracoronary adenosine 2.5 at screening.
• If subject is of childbearing potential, presents with a negative pregnancy test, and agrees to employ adequate birth control measures for the duration of the study.
• Subject is willing and able to comply with the requirements of the protocol.
• Stable medical therapy for 30 days prior to screening and until treatment with CLBS16; which includes standard medical therapy at the treating physician’s discretion (statin (unless not tolerated) ACE inhibitor, beta blocker, calcium channel blocker, 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.
• Prior evidence of obstructive heart disease including history of Percutaneous Coronary Intervention (PCI) and/or Coronary Artery Bypass Grafting (CABG).
• Planned percutaneous coronary intervention or CABG.
• Diagnosis of other specific cardiac disease such as severe valvular heart disease including:
  • aortic valve area < 1.5;
  • 3+ mitral regurgitation;
  • 3+ aortic insufficiency;
  • hypertrophic cardiomyopathy;
  • LVEF < %;
  • GFR < 30 mL/min/1.73m^2.
• 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 has known sensitivity to iron dextran.
• Subject tests positive for human immunodeficiency virus (HIV), hepatitis B or hepatitis C.
• Subject has active inflammatory disease or autoimmune disease, or is in a chronic immunosuppressive state.
• Recent history of abuse or current abuser of recreational drugs other than cannabis.
• 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.
• Any other condition which, in the opinion of the investigator, may preclude the subject from safe participation in the study or compromise data integrity.