Minimal residual disease and outcome characteristics in infant KMT2A-germline acute lymphoblastic leukaemia treated on the Interfant-06 protocol.

BACKGROUND: The outcome of infants with KMT2A-germline acute lymphoblastic leukaemia (ALL) is superior to that of infants with KMT2A-rearranged ALL but has been inferior to non-infant ALL patients. Here, we describe the outcome and prognostic factors for 167 infants with KMT2A-germline ALL enrolled in the Interfant-06 study. METHODS: Univariate analysis on prognostic factors (age, white blood cell count at diagnosis, prednisolone response and CD10 expression) was performed on KMT2A-germline infants in complete remission at the end of induction (EOI; n = 163). Bone marrow minimal residual disease (MRD) was measured in 73 patients by real-time quantitative polymerase chain reaction at various time points (EOI, n = 68; end of consolidation, n = 56; and before OCTADAD, n = 57). MRD results were classified as negative, intermediate (<5∗10-4), and high (≥5∗10-4). RESULTS: The 6-year event-free and overall survival was 73.9% (standard error [SE] = 3.6) and 87.2% (SE = 2.7). Relapses occurred early, within 36 months from diagnosis in 28 of 31 (90%) infants. Treatment-related mortality was 3.6%. Age <6 months was a favourable prognostic factor with a 6-year disease-free survival (DFS) of 91% (SE = 9.0) compared with 71.7% (SE = 4.2) in infants >6 months of age (P = 0.04). Patients with high EOI MRD ≥5 × 10-4 had a worse outcome (6-year DFS 61.4% [SE = 12.4], n = 16), compared with patients with undetectable EOI MRD (6-year DFS 87.9% [SE = 6.6], n = 28) or intermediate EOI MRD <5 × 10-4 (6-year DFS 76.4% [SE = 11.3], n = 24; P = 0.02). CONCLUSION: We conclude that young age at diagnosis and low EOI MRD seem favourable prognostic factors in infants with KMT2A-germline ALL and should be considered for risk stratification in future clinical trials.

Parental comprehension and satisfaction in informed consent in paediatric clinical trials: a prospective study on childhood leukaemia.

OBJECTIVE: To evaluate the extent to which parents are satisfied with and understand the information they are given when their consent is sought for their child to participate in a phase III randomised clinical trial and the reasons for their decision. PATIENTS AND METHOD: The authors carried out a prospective study. The authors included all parents whose consent was sought for their child to participate in the FRALLE 2000A protocol (acute lymphoblastic leukaemia) at two centres. The parents were questioned twice by a qualified psychologist using a semidirected interview, 1 and 6 months after consent was sought. RESULTS: 43 first interviews were carried out. All the parents declared they were satisfied with the explanations provided by the physician. 35 (81%) parents felt that the information provided with the request for consent was appropriate. Eight (19%) parents did not realise that their child had been included in a research protocol. 16 (39%) parents did not understand the concept of randomisation. Half the parents could explain neither the aim of the clinical trial nor the potential benefit of inclusion to their child. Only one third of the parents were aware that they had an alternative. The principal factor underlying their decision, as stated by 29 parents (67%), was confidence in the medical team. CONCLUSIONS: The parents signed consent forms without having fully understood all the elements specific to the experimental protocol. Rather, the parents based their decision on their confidence in the medical team, even when their child's life was at risk.

Incidence and prognostic impact of c-Kit, FLT3, and Ras gene mutations in core binding factor acute myeloid leukemia (CBF-AML).

In core binding factors (CBF) acute myeloid leukemia (AML), the disruption of CBFalpha/beta genes impairs normal hematopoietic differentiation and is supposed to cooperate with additional mutations promoting proliferation. The incidence and the prognosis of receptor tyrosine kinase (RTK) c-Kit and FLT3 mutations and Ras mutations were evaluated in 103 pediatric and adult patients with CBF-AML. c-Kit mutations were present in 17% patients. c-Kit exon 8 mutations were more frequent in inv(16) than in t(8;21) subset (20 versus 6%). Only one patient had FLT3-ITD but FLT3-D835 was as frequent as reported in AML population (7%). Ras mutations were significantly more frequent in inv(16) than in t(8;21) subset (36 versus 8%, P=0.001). RTK mutations were associated with a higher white blood cell count (WBC) (36 versus 21 G/L, P=0.05). FLT3 mutations were significantly associated with a shorter EFS and survival (P<0.0001 and P=0.0002) owing to an excess of early events. c-Kit mutations were associated with a shorter EFS and RFS (P=0.002 and P=0.003) in t(8;21) but not inv(16) patients. As previously observed, Ras mutations did not affect prognosis. Screening for RTK mutations may help to identify patients with a more adverse outcome and thus susceptible to benefit from intensified protocols or RTK inhibitors.

Treatment of childhood autoimmune haemolytic anaemia with rituximab.

Autoimmune haemolytic anaemia commonly has a severe course in young children, thus requiring multiple immunosuppressive treatments. Five children with refractory idiopathic autoimmune haemolytic anaemia, and one child with the disease after bone-marrow transplantation, were treated with rituximab-a monoclonal antibody against CD20. Tolerance of the treatment was good. However, circulating Bcells were absent and hypogammaglobulinaemia was seen for 9 months after treatment. All patients remained in complete remission 15-22 months after the start of rituximab therapy. Corticosteroids and immunosuppressive drugs were stopped or their dose markedly reduced. We suggest that rituximab could be a valuable treatment for autoimmune haemolytic anaemia, although a long-lasting but transient B-cell deficiency develops.