Vaccine booster for COVID-19 in patients with chronic lymphocytic leukemia

Randomized Observer-Blinded Phase 2 Trial of COVID-19 Booster With GEO-CM04S1 or mRNA Vaccine in Patients With Chronic Lymphocytic Leukemia

Phase 2 Interventional City of Hope Medical Center · NCT05672355

This study is testing a new COVID-19 booster vaccine to see if it works better than the standard vaccine for people with chronic lymphocytic leukemia.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment80 (estimated)
Ages18 Years and up
SexAll
SponsorCity of Hope Medical Center Academic / other
Drugs / interventionschimeric antigen receptor, prednisone
Locations1 site (Duarte, California)
Trial IDNCT05672355 on ClinicalTrials.gov

What this trial studies

This phase II trial evaluates the effectiveness of the GEO-CM04S1 vaccine compared to the standard of care vaccine in preventing COVID-19 infections among patients with chronic lymphocytic leukemia (CLL). The GEO-CM04S1 vaccine utilizes a modified vaccinia virus (MVA) backbone designed to enhance immune responses, particularly in individuals with compromised immune systems. The study will assess T cell-based immune responses, safety, and the durability of immunity over a 12-month period. Participants will receive either the new vaccine or the standard vaccine and will be monitored for COVID-19 infection rates and immune response metrics.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with a confirmed diagnosis of chronic lymphocytic leukemia who have received prior COVID-19 vaccinations.

Not a fit: Patients who have not been vaccinated against COVID-19 or those with severe comorbidities may not benefit from this study.

Why it matters

Potential benefit: If successful, this vaccine could significantly improve COVID-19 protection for patients with chronic lymphocytic leukemia.

How similar studies have performed: Other studies have shown promise in using modified viral vectors for vaccine development, suggesting potential success for this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Documented informed consent of the participant and/or legally authorized representative
* Age: \>= 18 years
* Eastern Cooperative Oncology Group (ECOG) =\< 1
* Histologically confirmed diagnosis of CLL according to World Health Organization (WHO) classification
* Prior COVID-19 Vaccination (2 or more Pfizer or Moderna) with last injection \>= 3 months prior
* Fully recovered from the acute toxic effects (except alopecia) to =\< Grade 1 to prior anti-cancer therapy
* White Blood Cells (WBC) \>= 1,000/mm\^3 (To be performed within 14 days prior to Day 1 of protocol therapy)
* Platelets \>= 50,000/mm\^3 (To be performed within 14 days prior to Day 1 of protocol therapy)
* Total bilirubin =\< 1.5 X upper limit of normal (ULN) (unless has Gilbert's disease) (To be performed within 14 days prior to Day 1 of protocol therapy)
* Aspartate aminotransferase (AST) =\< 2.5 x ULN (To be performed within 14 days prior to Day 1 of protocol therapy)
* Alanine transaminase (ALT) =\< 2.5 x ULN (To be performed within 14 days prior to Day 1 of protocol therapy)
* Creatinine clearance \<1.5 ULN (To be performed within 14 days prior to Day 1 of protocol therapy)
* Women of childbearing potential (WOCBP): negative urine or serum pregnancy test (To be performed within 14 days prior to Day 1 of protocol therapy)

  * If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required
* Agreement by females and males of childbearing potential to use an effective method of birth control or abstain from heterosexual activity for the course of the study through at least 6 weeks after the last vaccine injection

  * Childbearing potential defined as not being surgically sterilized (men and women) or have not been free from menses for \> 1 year (women only)

Exclusion Criteria:

* Known current SARS CoV-2 infection
* Prior Evusheld or other anti-SARS CoV-2 prophylaxis \< 2 weeks prior
* Prior hematopoietic cell transplantation (HCT) or chimeric antigen receptor (CAR) T cell therapy within the previous year
* Systemic corticosteroids required for chronic conditions at doses \> 0.5mg/kg/day prednisone equivalent within 7 days of enrollment
* Intensive cytotoxic therapies, T-cell depleting therapies, within 30 days of enrollment; however, patients with stable disease on maintenance therapies are allowed (See ConMeds for lists of acceptable and contraindicated therapies)
* Participants who have had a live vaccine =\< 30 days prior to administration of any dose of study vaccine or subjects who are =\< 2 weeks within administration of inactivated vaccines (e.g., influenza vaccine). Flu shots are allowed \> 2 weeks before a study vaccine injection and \> 2 weeks post study vaccine injection
* History of allergic reactions attributed to compounds of similar chemical or biologic composition to study agent (e.g., egg allergies)
* Active infection not controlled on appropriate therapy
* History of adverse event with a prior smallpox vaccination
* History of pericarditis or myocarditis
* Any MVA vaccine or poxvirus vaccine in the last 12 months
* Females only: Pregnant or breastfeeding
* Any other condition that would, in the Investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns with clinical study procedures
* Prospective participants who, in the opinion of the investigator, may not be able to comply with all study procedures (including compliance issues related to feasibility/logistics)

Where this trial is running

Duarte, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Chronic Lymphocytic LeukemiaCOVID-19 Infection
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.