A Phase 2 Study of Ruxolitinib With Chemotherapy in Children With Acute Lymphoblastic Leukemia

Inclusion Criteria:

- Eligible for study when participant is 1 year to 21 years at the time of diagnosis

- Eligible Ages in Australia and Canada; 2 years to 21 years

- De novo high-risk (HR) Ph-like B-ALL for which any of following criteria are present
at diagnosis:

- Age ≥ 10 years

- White blood cell (WBC) ≥ 50 × 10^3/μL

- CNS3 leukemia

- Systemic steroid pretreatment without presteroid WBC documentation

- One of the following Ph-like ALL genetic lesions must be present in the diagnostic
bone marrow or peripheral blood sample:

- CRLF2 rearrangement with JAK1 or JAK2 mutation (JAK+)

- CRLF2 rearrangement without JAK mutation

- Other JAK pathway alterations (eg, JAK2 fusions, erythropoietin receptor (EPO-R)
fusions, SH2B3 deletions, interleukin-7 receptor-alpha (IL7RA) mutations) with or
without CRLF2 rearrangement

- Completed a 4-drug Induction therapy regimen (modified aBFM regimen or equivalent) in
Study AALL1131 or as the institutional standard of care for HR B-ALL and have had
end-Induction minimal residual disease (MRD) assessed

- Male and female subjects of reproductive non childbearing potential or willing to take
appropriate precautions to avoid pregnancy or fathering a child for the duration of
study participation

Exclusion Criteria:

- Receipt of any other cytotoxic chemotherapy before Induction therapy, with exception
of hydroxyurea or steroid pretreatment

- Trisomy 21 (Down syndrome)

- BCR-ABL1-rearranged (Ph+) ALL

- Calculated creatinine clearance or radioisotope glomerular filtration rate < 70
mL/min/1.73 m^2

- Alanine aminotransferase ≥ 5 × upper limit of normal (ULN) for age

- Direct bilirubin ≥ 1.5 × ULN (may be assumed if total bilirubin is below ULN)

- History or evidence of cirrhosis

- Platelet count < 75 × 10^3/μL

- Absolute neutrophil count (ANC) < 750/μL

- Positive screen for hepatitis B or C

- Known human immunodeficiency virus infection