A Vaccine Booster (GEO-CM04S1) for the Prevention of 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

This phase II trial compares the effect of the GEO-CM04S1 vaccine with the current standard of care vaccine in preventing COVID-19 infections in patients with chronic lymphocytic leukemia (CLL). The GEO-CM04S1 vaccine uses a modified vaccinia virus (MVA) backbone that may be more effective at boosting COVID-19 immunity in patients with poor immune responses. MVA strongly induces T cell expansion (infection fighting blood cells) even in the background of a suppressed immune system, which is the case in the targeted CLL patient population. Using the GEO-CM04S1 vaccine may be more effective at preventing COVID-19 infection in patients diagnosed with CLL.

Study Overview

• Status: Suspended
• Conditions: Chronic Lymphocytic Leukemia; COVID-19 Infection
• Intervention / Treatment: Procedure: Biospecimen Collection; Biological: Synthetic MVA-based SARS-CoV-2 Vaccine COH04S1; Biological: mRNA COVID-19 Vaccine

Detailed Description

PRIMARY OBJECTIVE:

I. Estimate the T cell-based immune response rate on day 56 post-injection of synthetic MVA-based SARS-CoV-2 vaccine COH04S1 (GEO-CM04S1) vaccine boost administered at 2.5x10^8 plaque-forming unit (PFU) or standard of care (SOC) vaccine administered as standard of care.

SECONDARY OBJECTIVES:

I. Evaluate the safety of single-dose vaccine boost based on moderate and unacceptable toxicities up to day 28 post-injection for the GEO-CM04S1 and SOC vaccines.

II. Estimate the T cell-based immune response rate at day 112 post-injection of GEO-CM04S1 vaccine at 2.5x10^8 PFU vs SOC severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger ribonucleic acid (mRNA) vaccine administered as COVID-19 vaccine boosters.

III. Select the more promising vaccine to study further as a booster in patients with CLL.

IV. Evaluate SARS-CoV-2 S and N-specific Th1 vs Th2 polarization. V. Estimate the magnitude and durability of T-cell-based immune responses over a 12-month period.

VI. Estimate the levels and durability of SARS-CoV-2-specific IgG in a 12-month period.

VII. Evaluate levels of antibodies neutralizing SARS-CoV-2 in original strain and in variants of concern (VOC) based on the Centers for Disease Control and Prevention (CDC) definition using Spike-pseudotyped lentivirus.

VIII. Evaluate the overall safety profile during follow-up (12 months). IX. Estimate the incidence and severity of COVID-19 infection during follow-up (12 months).

EXPLORATORY OBJECTIVES:

I. Determine the SARS-CoV-2 variant by sequencing virus from polymerase chain reaction (PCR)-confirmed infected participants.

II. Evaluate activated/cycling and memory phenotype markers in SARS-CoV-2 stimulated T cells.

III. Estimate SARS-CoV-2-specfic serum IgA levels measured by enzyme-linked immunoassay (ELISA).

OUTLINE: Patients are randomized to 1 of 2 arms.

ARM I: Patients receive GEO-CM04S1 vaccine intramuscularly (IM) on days 0 and 84 on study.

ARM II. Patients receive mRNA vaccine injection IM on days 0 and 84 on study.

Patients undergo blood sample collections throughout the study and are monitored for 1 year.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • California
    • Duarte, California, United States, 91010
      • City of Hope Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm I (GEO-CM04S1); Patients receive GEO-CM04S1 vaccine IM on days 0 and 84 on study. Patients undergo blood sample collections throughout the study and are monitored for 1 year.	Procedure: Biospecimen Collection; Undergo blood sample collection; Other Names: Biological Sample Collection; Biospecimen Collected; Specimen Collection; Biological: Synthetic MVA-based SARS-CoV-2 Vaccine COH04S1; Given IM; Other Names: COH04S1; SARS-CoV-2 Vaccine COH04S1; sMVA-based SARS-CoV-2 Vaccine COH04S1
Active Comparator: Arm II (mRNA Covid-19 Vaccine); Patients receive mRNA vaccine injection IM on days 0 and 84 on study. Patients undergo blood sample collections throughout the study and are monitored for 1 year.	Procedure: Biospecimen Collection; Undergo blood sample collection; Other Names: Biological Sample Collection; Biospecimen Collected; Specimen Collection; Biological: mRNA COVID-19 Vaccine; Given IM; Other Names: COVID-19 mRNA Vaccine; mRNA-based COVID-19 Vaccine; SARS-CoV-2 mRNA Vaccine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
T cell response	Assessed by >= 3-fold increase in S-specific or N-specific IFN-gamma-secreting T cells over baseline at day 56 (Primary Immune Analysis [PIA]), using Enzyme-linked Immunosorbent Spot (ELISPOT) assay to quantify SARS CoV-2 reactive T cells. * Note: Missing immune response will not be imputed. Missing immune response will be categorized as no for intent-to-treat analysis but will be excluded in per-protocol analysis.	Baseline to day 56

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of adverse events (AEs) moderate toxicity (MOD)	Grade 2 AEs (based on Common Terminology Criteria for Adverse Events [CTCAE] version 5.0) probably or definitely attributable to vaccine boost, lasting >= 7 days. The primary toxicity analysis will be summarized in terms of type, severity, time of onset, duration, probable association with GEO-CM04S1 vaccine and reversibility or outcome.	From each injection to Day 28 post injection
Incidence of AEs unacceptable toxicity (UT)	Grade 3-5 AEs (based on CTCAE version 5.0) probably or definitely attributable to vaccine boost. The primary toxicity analysis will be summarized in terms of type, severity, time of onset, duration, probable association with GEO-CM04S1 vaccine and reversibility or outcome.	From each injection to Day 28 post injection
Incidence of myocarditis or pericarditis	Any grade probably or definitely attributable to vaccine boost.	Up to 42 days following final injection of study vaccine (GEO-CM04S1 or standard of care [SoC] mRNA-CoV-2 vaccine)
Incidence of serious adverse events (SAEs)	At least possibly related to vaccine booster injection, with the exception of hospitalization for grades 1 or 2 fever.	From each injection to Day 365 post injection
T cell response	As assessed by >= 3-fold increase in S-specific or N-specific IFN-gamma-secreting T cells, using ELISPOT assay to quantify SARS CoV-2 reactive T cells. Scatterplots of immune response markers across time points will be generated to visualize the temporal patterns.	Baseline to 28 days after the second booster injection
T cell fold-increase	ELISPOT assay of SARS CoV-2 reactive T cell cytokines (IFN-gamma, IL-4).	At all immune test time points (Baseline, and days 28, 56, 84, 112, 180 and 365)
SARS-CoV-2-S and -N specific IFNgamma (Th1) and IL-4 (Th2) cytokine levels following stimulation with overlapping peptide libraries specific for SARS-CoV-2	The immune response rate at day 112 and 90% CI will be calculated by arm. Continuous immune response markers will be summarized by means or geometric means and standard deviations if the assumption of normal distribution is not violated. Repeated immune response measurements at the multiple time points will be analyzed using generalized estimating equations (GEE) or mixed regression models. Scatterplots of immune response markers across time points will be generated to visualize the temporal patterns.	Up to 2 years
Level of antibodies neutralizing SARS-CoV-2 Spike pseudoviruses	Based on ancestral Wuhan strain and SARS-CoV-2 variants of concern (VOC) or variants of high consequence (VHC) based on Centers for Disease Control and Prevention (CDC) definition.	At day 56 after the first booster injection (PIA), at 28 days after the second booster injection (day 112), and at days 180 and 365
Levels of S- or N-specific IgG titers	Using quantitative enxyme-linked immunoassay (ELISA) based on World Health Organization (WHO) international standard for SARS-CoV-2 antibodies.	At day 56 after the first booster injection (PIA), 28 days after the second booster injection (day 112), and at days 180 and 365
Confirmed COVID-19 infection by PCR viral load		Baseline to 1 year
Severe COVID-19 infection by Food and Drug Administration (FDA) criteria		Baseline up to 1 year

Collaborators and Investigators

• Sponsor: City of Hope Medical Center
• Collaborators: National Cancer Institute (NCI)
• Investigators: Principal Investigator: Alexey V Danilov, City of Hope Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2023
• Primary Completion (Estimated): January 12, 2029
• Study Completion (Estimated): January 12, 2029

Study Registration Dates

• First Submitted: January 3, 2023
• First Submitted That Met QC Criteria: January 3, 2023
• First Posted (Actual): January 5, 2023

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 18, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Neoplasms; Chronic Disease; Disease Attributes; Immune System Diseases; Respiratory Tract Infections; Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Neoplasms by Histologic Type; Lung Diseases; Hematologic Diseases; Pneumonia, Viral; Pneumonia; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; Lymphatic Diseases; Lymphoproliferative Disorders; Immunoproliferative Disorders; Leukemia, B-Cell; Leukemia, Lymphoid; Leukemia; Pathological Conditions, Signs and Symptoms; Hemic and Lymphatic Diseases; COVID-19; Leukemia, Lymphocytic, Chronic, B-Cell; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Specimen Handling; CVnCoV COVID-19 vaccine; COH04S1 COVID-19 vaccine
• Other Study ID Numbers: 22416 (Other Identifier: City of Hope Medical Center); P30CA033572 (U.S. NIH Grant/Contract); NCI-2022-10303 (Registry Identifier: CTRP (Clinical Trial Reporting Program))

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No