Trial Outcomes & Findings for Vaccine Immune Recovery After Leukemia (NCT NCT05622682)

NCT ID: NCT05622682

Last Updated: 2026-01-26

Results Overview

Infections include clinical and/or microbiologically confirmed infections as well as patient-reported infections during follow-up. All unique infections for a given subject will be captured and included in the final infection rate per person time estimate. The total number of unique infections identified within the first year after completing chemotherapy will be reported as a rate per patient-year. Patients will be censored at time of loss to follow-up, relapse, or death.

Recruitment status

COMPLETED

Target enrollment

89 participants

Primary outcome timeframe

1 year

Results posted on

2026-01-26

Participant Flow

Recruitment period: September 2022 - October 2024 Participating sites: Six pediatric hemotology/oncology centers in the U.S. Patients completing chemotherapy for acute lymphoblastic leukemia during the study period screened for eligibility.

This was an observational study with only one study arm for enrollment of participants recently completing chemotherapy for acute lymphoblastic leukemia.

Participant milestones

Participant milestones
Measure
Child, Adolescent, and Young Adult Survivors of Acute Lymphoblastic Leukemia
This group includes survivors of acute lymphoblastic leukemia between ages 3 and 31 who completed chemotherapy for acute lymphoblastic leukemia within +/- 3 months of the time of study enrollment and were followed until one year off-therapy.
Overall Study
STARTED
89
Overall Study
3 Months Off-therapy Follow-up
88
Overall Study
6 Months Off-therapy Follow-Up
86
Overall Study
12 Months Off-therapy Follow-up
84
Overall Study
COMPLETED
84
Overall Study
NOT COMPLETED
5

Reasons for withdrawal

Reasons for withdrawal
Measure
Child, Adolescent, and Young Adult Survivors of Acute Lymphoblastic Leukemia
This group includes survivors of acute lymphoblastic leukemia between ages 3 and 31 who completed chemotherapy for acute lymphoblastic leukemia within +/- 3 months of the time of study enrollment and were followed until one year off-therapy.
Overall Study
Lost to Follow-up
2
Overall Study
Censored Due to ALL Relapse
3

Baseline Characteristics

Age at which study participants were first diagnosed with acute lymphoblastic leukemia.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Child, Adolescent, and Young Adult Survivors of Acute Lymphoblastic Leukemia
n=89 Participants
This group includes survivors of acute lymphoblastic leukemia between ages 3 and 31 who completed chemotherapy for acute lymphoblastic leukemia within +/- 3 months of the time of study enrollment and were followed until one year off-therapy.
Sex: Female, Male
Female
38 Participants
n=41 Participants
Sex: Female, Male
Male
51 Participants
n=41 Participants
Race (NIH/OMB)
American Indian or Alaska Native
2 Participants
n=41 Participants
Race (NIH/OMB)
Asian
9 Participants
n=41 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=41 Participants
Race (NIH/OMB)
Black or African American
9 Participants
n=41 Participants
Race (NIH/OMB)
White
57 Participants
n=41 Participants
Race (NIH/OMB)
More than one race
3 Participants
n=41 Participants
Race (NIH/OMB)
Unknown or Not Reported
9 Participants
n=41 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
11 Participants
n=41 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
78 Participants
n=41 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=41 Participants
Acute Lymphoblastic Leukemia Subtype and Risk Classification
Standard-risk B-cell Acute Lymphoblastic Leukemia
47 Participants
n=41 Participants
Acute Lymphoblastic Leukemia Subtype and Risk Classification
High-risk B-cell Acute Lymphoblastic Leukemia
27 Participants
n=41 Participants
Acute Lymphoblastic Leukemia Subtype and Risk Classification
T-cell Acute Lymphoblastic Leukemia
15 Participants
n=41 Participants
Age, Continuous
6.0 Years
n=41 Participants • Age at which study participants were first diagnosed with acute lymphoblastic leukemia.

PRIMARY outcome

Timeframe: 1 year

Population: Analyzed 88 total participants; 1 participant lost to follow-up between enrollment and first post-enrollment study encounter.

Infections include clinical and/or microbiologically confirmed infections as well as patient-reported infections during follow-up. All unique infections for a given subject will be captured and included in the final infection rate per person time estimate. The total number of unique infections identified within the first year after completing chemotherapy will be reported as a rate per patient-year. Patients will be censored at time of loss to follow-up, relapse, or death.

Outcome measures

Outcome measures
Measure
Child, Adolescent, and Young Adult Survivors of Acute Lymphoblastic Leukemia
n=88 Participants
This group includes survivors of acute lymphoblastic leukemia between ages 3 and 31 who completed chemotherapy for acute lymphoblastic leukemia within +/- 3 months of the time of study enrollment and were followed until one year off-therapy.
Incident Infection Rate in Participants During the First Year Post-acute Lymphoblastic Leukemia Therapy
3.60 Events per person-year

SECONDARY outcome

Timeframe: 1 year

Population: For each timepoint, only patients with (A) any history of measles vaccine prior to chemotherapy and NO history of measles vaccine after chemotherapy and (B) serum available for testing at the timepoint are included in this analysis.

The seroprevalence proportions for measles antibodies will be determined for the entire cohort and by demographics at each study follow-up time point (3, 6, and 12 months). Additionally, seroprevalence at each time point will be described for participants who had and had not completed their primary vaccine series before starting chemotherapy.

Outcome measures

Outcome measures
Measure
Child, Adolescent, and Young Adult Survivors of Acute Lymphoblastic Leukemia
n=88 Participants
This group includes survivors of acute lymphoblastic leukemia between ages 3 and 31 who completed chemotherapy for acute lymphoblastic leukemia within +/- 3 months of the time of study enrollment and were followed until one year off-therapy.
Proportion of Patients With Seroprevalence of Measles Antibodies at Each Study Timepoint
Measles-specific Immunoglobulin-G Level Indicative of Seroprotection at 3 Months Off-therapy
37 Participants
Proportion of Patients With Seroprevalence of Measles Antibodies at Each Study Timepoint
Measles-specific Immunoglobulin-G Level Indicative of Seroprotection at 6 Months Off-therapy
30 Participants
Proportion of Patients With Seroprevalence of Measles Antibodies at Each Study Timepoint
Measles-specific Immunoglobulin-G Level Indicative of Seroprotection at 12 Months Off-therapy
29 Participants

SECONDARY outcome

Timeframe: 1 year

Population: For each timepoint, participants with (A) any history of varicella vaccine prior to chemotherapy and NO history of varicella vaccine after chemotherapy and (B) serum available for testing at the timepoint are included in the analysis.

The seroprevalence proportions for varicella antibodies will be determined for the entire cohort and by demographics at each study follow-up time point (3, 6, and 12 months). Additionally, seroprevalence at each time point will be described for participants who had and had not completed their primary vaccine series before starting chemotherapy.

Outcome measures

Outcome measures
Measure
Child, Adolescent, and Young Adult Survivors of Acute Lymphoblastic Leukemia
n=88 Participants
This group includes survivors of acute lymphoblastic leukemia between ages 3 and 31 who completed chemotherapy for acute lymphoblastic leukemia within +/- 3 months of the time of study enrollment and were followed until one year off-therapy.
Proportion of Patients With Seroprevalence of Varicella Antibodies at Each Study Timepoint
Varicella-specific Immunoglobulin-G Level Indicative of Seroprotection at 3 Months Off-therapy
9 Participants
Proportion of Patients With Seroprevalence of Varicella Antibodies at Each Study Timepoint
Varicella-specific Immunoglobulin-G Level Indicative of Seroprotection at 6 Months Off-therapy
8 Participants
Proportion of Patients With Seroprevalence of Varicella Antibodies at Each Study Timepoint
Varicella-specific Immunoglobulin-G Level Indicative of Seroprotection at 12 Months Off-therapy
11 Participants

SECONDARY outcome

Timeframe: 1 year

Population: Patients with any history of pneumococcal vaccine and serum available for testing at each timepoint were included.

The seroprevalence proportions for pneumococcal antibodies (23 serotypes) will be determined for the entire cohort and by demographics at each study follow-up time point (3, 6, and 12 months). Additionally, seroprevalence at each time point will be described for participants who had and had not completed their primary vaccine series before starting chemotherapy.

Outcome measures

Outcome measures
Measure
Child, Adolescent, and Young Adult Survivors of Acute Lymphoblastic Leukemia
n=79 Participants
This group includes survivors of acute lymphoblastic leukemia between ages 3 and 31 who completed chemotherapy for acute lymphoblastic leukemia within +/- 3 months of the time of study enrollment and were followed until one year off-therapy.
Proportion of Patients With Seroprevalence of Pneumococcus Antibodies at Each Study Timepoint
Patients with Positive Titers to > 50% of Pneumococcal Vaccine Serotypes at 3 Months Off-therapy · Positive Titers Among Patients with Pneumococcal Vaccine Only Pre-chemo
0 Participants
Proportion of Patients With Seroprevalence of Pneumococcus Antibodies at Each Study Timepoint
Patients with Positive Titers to > 50% of Pneumococcal Vaccine Serotypes at 3 Months Off-therapy · Positive Titers Among Patients with Vaccine Pre-chemo and Post-chemo Booster
0 Participants
Proportion of Patients With Seroprevalence of Pneumococcus Antibodies at Each Study Timepoint
Patients with Positive Titers to > 50% of Pneumococcal Vaccine Serotypes at 3 Months Off-therapy · Negative Titers
72 Participants
Proportion of Patients With Seroprevalence of Pneumococcus Antibodies at Each Study Timepoint
Patients with Positive Titers to > 50% of Pneumococcal Vaccine Serotypes at 6 Months Off-therapy · Positive Titers Among Patients with Pneumococcal Vaccine Only Pre-chemo
0 Participants
Proportion of Patients With Seroprevalence of Pneumococcus Antibodies at Each Study Timepoint
Patients with Positive Titers to > 50% of Pneumococcal Vaccine Serotypes at 6 Months Off-therapy · Positive Titers Among Patients with Vaccine Pre-chemo and Post-chemo Booster
1 Participants
Proportion of Patients With Seroprevalence of Pneumococcus Antibodies at Each Study Timepoint
Patients with Positive Titers to > 50% of Pneumococcal Vaccine Serotypes at 6 Months Off-therapy · Negative Titers
74 Participants
Proportion of Patients With Seroprevalence of Pneumococcus Antibodies at Each Study Timepoint
Patients with Positive Titers to > 50% of Pneumococcal Vaccine Serotypes at 12 Months Off-therapy · Positive Titers Among Patients with Pneumococcal Vaccine Only Pre-chemo
4 Participants
Proportion of Patients With Seroprevalence of Pneumococcus Antibodies at Each Study Timepoint
Patients with Positive Titers to > 50% of Pneumococcal Vaccine Serotypes at 12 Months Off-therapy · Positive Titers Among Patients with Vaccine Pre-chemo and Post-chemo Booster
4 Participants
Proportion of Patients With Seroprevalence of Pneumococcus Antibodies at Each Study Timepoint
Patients with Positive Titers to > 50% of Pneumococcal Vaccine Serotypes at 12 Months Off-therapy · Negative Titers
71 Participants

Adverse Events

Child, Adolescent, and Young Adult Survivors of Acute Lymphoblastic Leukemia

Serious events: 3 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure
Child, Adolescent, and Young Adult Survivors of Acute Lymphoblastic Leukemia
n=89 participants at risk
This group includes survivors of acute lymphoblastic leukemia between ages 3 and 31 who completed chemotherapy for acute lymphoblastic leukemia within +/- 3 months of the time of study enrollment and were followed until one year off-therapy.
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Relapse of acute lymphoblastic leukemia
3.4%
3/89 • From enrollment to end of follow up, approximately 1 year
This study was observational in nature. Participants were monitored for death, relapse of acute lymphoblastic leukemia, or diagnosis of secondary malignancy during the follow-up period.
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Diagnosis of secondary malignancy
0.00%
0/89 • From enrollment to end of follow up, approximately 1 year
This study was observational in nature. Participants were monitored for death, relapse of acute lymphoblastic leukemia, or diagnosis of secondary malignancy during the follow-up period.

Other adverse events

Adverse event data not reported

Additional Information

Morgan Hammershaimb

Children's Hospital of Philadelphia

Phone: 267-426-9727

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place