12th Congress of the European Hematology ... - Haematologica

low up of ABL KD mutations’ level in imatinib resistant pts. Patients and
Methods. Pt 1 is a 73 years old lady with CML of 11 months duration
treated with nilotinib for accelerated phase CML. Pt 2 is a 30 years old
man with CML of 8 months duration treated with nilotinib for blast crisis
and on further progression with MK-0457. ABL KD mutation level
was determined on cDNA extracted from peripheral blood, with a sensitive
high throughput MALDI-TOF based assay using the SEQUENOM
MassARRAY? system and specific primers designed for the detection of
each of 27 ABL KD mutations. The assay involves PCR amplification of
the region containing the mutation of interest, SAP treatment to remove
excess dNTPs, addition of DNA polymerase along with a mixture of
dideoxy and deoxy NTPs that allows extension of the hME primer
through the mutation site and generates allele-specific extension products,
cleanup of the extension reaction to remove salt, spotting of the
extension product into 384 SpectroCHIPs and the analysis of the spotted
product using the MALDI-TOF mass spectrometry. We have previously
published the sensitivity of our method which is 1.5-3% mutated
clone in the sample analyzed (Leukemia 2007, in press). Results were
confirmed by direct cDNA sequencing analysis. Results. Two ABL KD
mutations were found in pt 1 before commencing therapy with nilotinib:
M244V and F359V; the relative proportion of M244V mutation to wild
type (WT) ABL was 45% and of F359V mutation to WT ABL 20%.
Mutation levels were further analyzed at 2 months intervals during therapy
with nilotinib and showed a decrease in the relative proportion of
M244V mutation until disappearance and an increase in the relative proportion
of F359V mutation that reached 40% in the last sample analyzed.
Clinically, the pt did not achieve CHR after six months therapy
with nilotinib, suggesting that F359V but not M244V is associated with
clinical resistance to nilotinib. Pt 2 was treated with nilotinib for 3
months after which he developed a second blast crisis. At that time
T315I mutation was found with a relative proportion of 50% to WT
ABL. After 2 courses of MK-0457 there was a decrease in peripheral blast
count with a disappearance of the T315I mutation, suggesting persistence
of blasts with WT ABL. Conclusion. Follow up of ABL KD mutation
level during therapy with new generation kinase inhibitors is informative
and may influence future therapeutic decisions.
1436
CLINICAL CHARACTERISTICS AND OUTCOMES OF HEPATITIS C VIRUS POSITIVE
DIFFUSE LARGE B-CELL LYMPHOMA
B.B. Park, 1 J.S. Kim, 2 H.J. Kang, 3 B.Y. Ryoo, 3 J.H. Kang, 4 H.Y. Kim, 5
B.S. Kim, 6 S.Y. Oh, 7 H.C. Kwon, 7 J.H. Won, 8 K. Kim, 9 K. Park, 9
C. Suh, 10 W.S. Kim9 1 Hanyang University College of Medicine, SEOUL; 2 Yonsei University College
of Medicine, SEOUL; 3 Korea Cancer Center Hospital, SEOUL; 4 Gyeongsang
National University Hospital, JIN-JU; 5 Yonsei University Wonju College of
Medic, WONJU; 6 Seoul Veterans Hospital, SEOUL; 7 Dong-A University College
of Medicine, BUSAN; 8 Soonchunhyang University College of Medi,
SEOUL; 9 Samsung Medical Center, SEOUL; 10 University of Ulsan College of
Medicine, SEOUL, South-Korea
Background. Most of subtypes in previous studies about association
between hepatitis C virus (HCV) infection and non-Hodgkin’s lymphoma
(NHL) are low grade NHL, while limited data are available to
characterize HCV-related diffuse large B-cell lymphoma (DLBL). We conducted
this retrospective study to investigate distinctive clinical characteristics
and outcomes of HCV-positive DLBL. Methods. Total 32 cases
of HCV-positive DLBL from 9 institutions in Korea were analyzed for
evaluation of clinical characteristics and outcomes. We compared the
clinical characteristics and outcomes of HCV-positive DLBL to those of
371 patients with HCV-negative DLBL. Results. The HCV-positive DLBL
was associated with a higher portion of old age (≥60) at diagnosis (59.4%
vs 36.1%, p=0.009) and less likely to have extra-nodal involvement
(53.1% vs 71.1%, p=0.044) than HCV-negative DLBL. The nodal presentation
was only independent factor favorably influencing the event
free survival (EFS) in HCV-positive DLBL (HR=0.11, 95%CI; 0.01-0.95,
p=0.012). In comparison to patients with HCV-negative DLBL, HCVpositive
DLBL patients had a superior EFS, especially in cases of age≥60
and nodal presentation (p=0.047, p=0.023) Conclusions. HCV-positive
DLBL is more common in old age and relatively less presented with
extranodal involvement than HCV-negative DLBL in Korea. The good
prognosis of HCV-positive DLBL seems to be correlated with transformed
low-grade NHL.
12 th Congress of the European Hematology Association
1437
A PHASE I/II STUDY OF ALL-TRANS RETINOIC ACID COMBINED WITH CONVENTIONAL
CHEMOTHERAPY IN INFANTS WITH MLL-REARRANGED LEUKEMIA
L. Fechina, 1 E. Shorikov, 2 O. Khlebnikova, 1 O. Streneva, 1 I. Vyatkin, 2
G. Tsaur, 2 L. Saveliev, 3 T. Verzhbitskaya, 1 A. Karachunsky4 1 Regional Children's Hospital, EKATERINBURG; 2 Research Institute of Cells
Technologies, EKATERINBURG; 3 Ural State Medical Academy, EKATERIN-
BURG; 4 Research Center of Pediatric Hematology, MOSCOW, Russian Federation
Background. MLL-rearranged leukemia in infants is a unique leukemic
subset with short latency, extremely aggressive clinical course and unacceptable
poor survival. MLL-fusion genes are participating in early progenitors’
differentiation block with following transformation to the
leukemic clone. In order to improve treatment results in infants with
MLL-leukemia we conducted Phase I/II clinical study of all-trans retinoic
acid (ATRA) application in combination with conventional chemotherapy.
ATRA-a natural derivate of provitamin A has been approved in
treatment of acute promyelocytic leukemia and demonstrates differentiating,
antiproliferative and proapoptotic activity. We are hypothesizing
that ATRA is able to affect the differentiating arrest in the leukemic
cells and induce maturation to the normal progenitors. Aim. To evaluate
the tolerability and efficacy of the ATRA containing regimen in infants
with primary diagnosed MLL-leukemia. Patients and Methods. Treatment
design included alternating 1-2 weeks ATRA courses in daily dose
25mg/m 2 started on the day 36 of induction chemotherapy. Chemotherapy
is referred to the ALL-MB 91 for the intermediate risk group and to
the modified ALL-BFM 90 high risk (HR) branch with high dose
methotrexate reduction. Maintenance therapy included 14 days ATRA
courses together with reinduction pulses of vincristin, and dexamethasone.
To avoid severe adverse effects cranial irradiation has been omitted
and substituted by five additional intrathecal triplets. Patients with
MLL/AF4 and nonresponders on the day 36/43 were determined as a HR
group. All the rest patients were stratified to the intermediate risk schedule.
Trial has been approved by the local Ethical Committee. Parents
have signed the informed consent. From September 2003 till the October
2005 four patients aged 1-10 months with MLL-rearranged acute
leukemia have been admitted to our clinic and are the subjects of this
study. All of them have had bulky extramedullary disease and high white
blood cells (WBC) count: 410×10 9 /L; 242×10 9 /L; 131×10 9 /L and 70×10 9 /L.
Patient with the highest WBC level has been considered to be positive
for CNS involvement due to the traumatic first lumbar puncture. All the
patients demonstrated BI immunophenotype. Three of four patients
have presented t(4;11)(q21;q23) and MLL/AF4. Translocation
t(11;19)(q23;p13) and MLL/ENL was detected in patient with the lowest
initial WBC. Results. All the patients responded well to the initial
treatment and achieved complete remission on the day 36. But despite
of good hematological response, fusion genes were detectable by nested
RT-PCR in all cases. Three of four patients (one with MLL/ENL and
two with MLL/AF4 chimeric transcripts) became PCR negative after the
first ATRA course. In fourth case MLL/AF4 transcript gradually decreased
and disappeared later - after the 7th course of ATRA. The follow up time
is as follow: 42, 22, 17 and 16 months. At the present time all the patients
are in molecular remission for: 38, 19, 16 and 9 months respectively. No
severe adverse effects of ATRA have been registered. Summary. Our
study demonstrated acceptable tolerability and satisfied efficacy of
ATRA containing treatment in infants with MLL-leukemia. Referring to
this encouraging experience we have developed a pilot MLL-Baby 2006
protocol intended for treatment of infants’ leukemia.
1438
CHRONIC LYMPHOID LEUKEMIA (B-CLL) & LOW GRADE NON HODGKIN LYMPHOMA
(LG-NHL) TREATMENT WITH FLUDARABINE (1995 2007)
J. Novoa, B. Beñaran, L. Rojo, S. Brignoni, M. Luongo, R. De Bellis
Ministry of Health, MONTEVIDEO, Uruguay
Background. fludarabine (F) has become the standard first line therpay
for chronic lymphoid leukemia (CLL) in younger patients. Aims. To assess
the efficacy, safety and quality of life of F in previously untreated LLC(B)
and low grade Non Hodgkin Lymphoma (NHL-LG) in a Group of Medical
Institutions in Uruguay. Methods. 213 patients in the period 1995-
2007 were evaluated.165 of them received the intravenous formulation
(1995-2007) and 48 the oral one (2002-2007). CLL 131 patients and NHL-
LG 82. Age: 44-85 years old, media 67 years old. Gender: male 115:
female 98. Inclusion criteria for CLL-B was Binet stages B, C and A progressive
(Ap), 18 to 85 years old, non multiorganic failure, performance
haematologica/the hematology journal | 2007; 92(s1) | 513