Comparing a new COVID-19 vaccine to standard mRNA vaccines in blood cancer patients

A Phase 2 Randomized, Multi-center Study of GEO-CMO4S1 (SARS-CoV-2 Vaccine) Versus mRNA SARS-CoV-2 Vaccine in Patients Post Cellular Therapy for Hematological Malignancies

Phase 2 Interventional GeoVax, Inc. · NCT04977024

This study is testing a new COVID-19 vaccine in blood cancer patients who have had a stem cell transplant to see if it works better than the standard mRNA vaccines.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment240 (estimated)
Ages18 Years and up
SexAll
SponsorGeoVax, Inc. Industry-sponsored
Drugs / interventionsrituximab, chimeric antigen receptor, prednisone
Locations6 sites (Duarte, California and 5 other locations)
Trial IDNCT04977024 on ClinicalTrials.gov

What this trial studies

This phase 2 trial evaluates the immune response to the GEO-CM04S1 vaccine, a modified vaccinia Ankara vaccine, in patients with blood cancer who have undergone stem cell transplant or cellular therapy. Participants are randomized to receive either the GEO-CM04S1 vaccine or a standard mRNA SARS-CoV-2 vaccine, with the aim of assessing the biological activity, safety, and durability of immune responses. The study includes follow-up assessments to monitor immune responses and any incidental COVID-19 infections over a year.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with blood cancer who have received a stem cell transplant or cellular therapy at least three months prior.

Not a fit: Patients who are not eligible include those with active blood cancer or those who have not undergone the required therapies.

Why it matters

Potential benefit: If successful, this study could enhance protection against COVID-19 in patients with blood cancer, potentially reducing severe disease outcomes.

How similar studies have performed: Other studies have shown promise with similar vaccine approaches, but this specific vaccine is novel in this patient population.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Documented informed consent of the participant
* Age \>=18 years
* Eastern Cooperative Oncology Group (ECOG) =\<1
* Allogeneic or autologous hematopoietic cell transplant (HCT), cellular therapy (chimeric antigen receptor \[CAR\] T-cell) recipients who are at \>= 3 months of infusion date of respective regimen
* Platelets \>= 50,000/mm\^3 (to be performed within 30 days prior to day 0 of protocol therapy unless otherwise stated)
* White blood cells (WBCs) \>= 1000/mm\^3 (to be performed within 30 days prior to day 0 of protocol therapy unless otherwise stated)
* Total bilirubin \< 1.5 X upper limit of normal (ULN) (to be performed within 30 days prior to day 0 of protocol therapy unless otherwise stated)
* Aspartate aminotransferase (AST) \< 2.5 X ULN (to be performed within 30 days prior to day 0 of protocol therapy unless otherwise stated)
* Alanine aminotransferase (ALT) \< 2.5 X ULN (to be performed within 30 days prior to day 0 of protocol therapy unless otherwise stated)
* Creatinine \< 1.5 X ULN (to be performed within 30 days prior to day 0 of protocol therapy unless otherwise stated)
* Negative COVID-19 PCR test
* Women of childbearing potential (WOCBP): negative urine or serum pregnancy test (to be performed within 30 days prior to day 0 of protocol therapy unless otherwise stated). If the urine pregnancy test is inconclusive 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 dose of protocol therapy

  * 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:

* Systemic corticosteroids required for chronic conditions at doses \> 0.5mg/kg/day prednisone equivalent within 7 days of enrollment
* Prior Evusheld or other anti-SARS CoV-2 prophylaxis \< 2 weeks prior to enrollment
* Therapies that cause profound T-cell or B cell depletion within 30 days of enrollment
* Maintenance therapies (e.g. rituximab, Bruton tyrosine kinase inhibitors, Janus kinase inhibitors) within 30 days of enrollment
* Received investigational or licensed SARS-CoV-2 vaccines after their qualifying cellular therapy. Patients who received a SARS- CoV-2 vaccine prior to cellular therapy are eligible for this trial, as revaccination for these patients (e.g. flu and shingles vaccine) is standard of care.
* Received a live vaccine ≤30 days prior to administration 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 the first injection and \> 2 weeks post 2nd injection
* History of allergic reactions attributed to compounds of similar chemical or biologic composition to vaccine agents
* History of adverse event with a prior smallpox vaccination
* Any MVA vaccine or poxvirus vaccine in the last 12 months
* History (suspected or confirmed) of myocarditis or pericarditis
* Clinically significant uncontrolled illness
* Females only: Pregnant or breastfeeding
* Any other condition that would, in the Investigator's judgment, contraindicate the subject'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)
* Anyone considered to be in a vulnerable population as defined in 45 CFR §46.111 (a)(3) and 45 CFR §46, Subparts B-D

Where this trial is running

Duarte, California and 5 other locations

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 COVID-19 InfectionHematopoietic and Lymphoid System NeoplasmLeukemiaLymphomaPlasma Cell Myeloma
Last reviewed 2026-06-10 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.