Literature Scan
and 17 patients (81%) had no marrow
disease detected by high-resolution flow cy-
tometry. “Approximately half of the patients
(58%) who were evaluated by immuno-
globulin heavy chain (IGH) sequencing
to detect residual tumor in [the] marrow
lacked detectable malignant IGH copies,”
the authors found.
Marrow clearance was associated with
a non-significant improved PFS: Median
PFS for detectable versus not detectable
malignant IGH copies was 8.5 months and
not reached, respectively (p=0.063). Median
OS was not reached in either group.
In addition to demonstrating the
feasibility of anti-CD19 CAR T-cell therapy
for this high-risk population, “these data
indicate that early restaging by tumor size
criteria alone, four weeks after CAR T-cell
administration, may not be the optimal
determinant of prognosis, as suggested
after immune checkpoint blockade in other
malignancies,” the authors noted. “Addi-
tional studies will be required to determine
whether strategies such as IGH sequencing,
[positron emission tomography] imaging,
or delayed restaging after CAR T-cell im-
munotherapy of CLL can identify patients
who might benefit from additional CAR
T-cell infusions to improve outcomes.”
The study is limited by its single-center
design and small patient population. Two
patients received less than the target CAR
T-cell dose, which may have limited the
findings. The low incidence of complete
elimination of bulky nodal disease suggests
that the malignant lymph node environ-
ment may impair CAR T-cell infiltration or
function.
The authors report no financial conflicts.
REFERENCE
Turtle CJ, Hay KA, Hanafi LA, et al. Durable molecular remissions in chronic
lymphocytic leukemia treated with CD19-specific chimeric antigen receptor-
modified T cells after failure of ibrutinib. J Clin Oncol. 2017;35:3010-20.