Auvo Rauhala

Clonal expansion of T/NK-cells during tyrosine kinase inhibitor dasatinib therapy.

Dasatinib, a broad-spectrum tyrosine kinase inhibitor (TKI), predominantly targets BCR-ABL and SRC oncoproteins and also inhibits off-target kinases, which may result in unexpected drug responses. We identified 22 patients with marked lymphoproliferation in blood while on dasatinib therapy. Clonality and immunophenotype were analyzed and related clinical information was collected. An abrupt lymphocytosis (peak count range 4–20 × 109/l) with large granular lymphocyte (LGL) morphology was observed after a median of 3 months from the start of therapy and it persisted throughout the therapy. Fifteen patients had a cytotoxic T-cell and seven patients had an NK-cell phenotype. All T-cell expansions were clonal. Adverse effects, such as colitis and pleuritis, were common (18 of 22 patients) and were preceded by LGL lymphocytosis. Accumulation of identical cytotoxic T cells was also detected in pleural effusion and colon biopsy samples. Responses to dasatinib were good and included complete, unexpectedly long-lasting remissions in patients with advanced leukemia. In a phase II clinical study on 46 Philadelphia chromosome-positive acute lymphoblastic leukemia, patients with lymphocytosis had superior survival compared with patients without lymphocytosis. By inhibiting immunoregulatory kinases, dasatinib may induce a reversible state of aberrant immune reactivity associated with good clinical responses and a distinct adverse effect profile.

Depth of response assessed by quantitative ASO-PCR predicts the outcome after stem cell transplantation in multiple myeloma

Achievement of complete response (CR) is a new goal of therapy for multiple myeloma (MM). By sensitive methods, the depth of response can be measured even among the patients in CR. We used a sensitive real‐time quantitative polymerase chain reaction by allele‐specific primers (qASO‐PCR) to assess the level of minimal residual disease (MRD) in bone marrow of 37 patients with myeloma who had achieved CR/near‐to‐CR after autologous or allogeneic stem cell transplantation (SCT). Allele‐specific primers could be successfully designed for 86% of patients. Three to six months after autotransplantation, the PCR target was not detectable in 53% of patients (16/30 patients), and the respective figure after allotransplantation was 71% (5/7 patients); the median sensitivity of PCR assay was <0.002%. The proportion of patients without detectable PCR target was 22% of all autotransplanted patients. A threshold level of 0.01% in the qASO‐PCR assay 3–6 months after SCT was found to be a useful cut‐off limit to divide the patients into two prognostic groups: MRD low/negative vs. MRD high. Low/negative MRD after SCT was a significant predictive factor for the prolongation of progression free (70 vs. 19 months; P = 0.003) and suggestively also for overall survival. We conclude that not only CR but also its depth is important for the long‐term outcome in MM.

A novel dasatinib-sensitive RCSD1-ABL1 fusion transcript in chemotherapy-refractory adult pre-B lymphoblastic leukemia with t(1;9)(q24;q34)

Dasatinib, a wide-spectrum tyrosine kinase inhibitor (TKI), has shown notable clinical activity in Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) patients carrying a 9;22 translocation and the resulting BCR-ABL1 fusion gene.[1][1] In other subtypes of ALL, its clinical

Prolonged immunochemotherapy with rituximab, cytarabine and fludarabine added to cyclophosphamide, doxorubicin, vincristine and prednisolone and followed by rituximab maintenance in untreated elderly patients with mantle cell lymphoma: a prospective study by the Finnish Lymphoma Group

Abstract There is no consensus on treatment strategies for elderly patients with mantle cell lymphoma (MCL). In this prospective phase II study we investigated whether the poor outcome could be improved, with reasonable toxicity, by prolonging the immunochemotherapy. Ten cycles of alternating cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP)/cytarabine (AraC) with eight doses of rituximab (R) were given as induction. The potential synergism of intermediate-dose AraC and fludarabine was tested in cycles 6–8. Induction was followed by bimonthly rituximab maintenance for 2 years. The median age of the 60 included patients was 74 years, and the Mantle Cell Lymphoma International Prognostic Index (MIPI) was intermediate or high risk in 98% of the patients. The overall response rate was 95% (complete response/complete response unconfirmed 87%). The response of 11 patients improved with cycles 6–8 (R-fludarabine-AraC). Progression-free survival was 70% and overall survival 72% at 4 years, respectively. Treatment related mortality was 2%. Severe infections were rare, with only one grade 4 infection. More dose reductions were needed during fludarabine-containing courses as compared to R-AraC. In 20 patients a transient grade 4 neutropenia without severe infections was recorded during maintenance. In conclusion, elderly patients with MCL can be treated relatively intensively with acceptable toxicity.

Stem cell transplantation in poor‐risk chronic lymphocytic leukemia: assessment of post‐transplant minimal residual disease using four‐ and six‐color flow cytometry and allele‐specific RQ‐PCR

A total of 178 bone marrow samples were taken for minimal residual disease (MRD) analysis after 34 stem cell transplantations for poor‐risk chronic lymphocytic leukemia, and 86 of them were analyzed in parallel by flow cytometry and allele‐specific oligonucleotide‐PCR (ASO‐PCR). ASO primer was successfully designed for all patients whose frozen diagnosis samples were available. Flow cytometry and ASO‐PCR were concordant, i.e. both either positive or both negative, in 78% of the analyses. Flow cytometry did not detect MRD in any of the samples that were PCR‐negative cases. In contrast, ASO‐PCR detected MRD in samples that were negative for MRD by flow cytometry in 22% of the analyses. In one patient, the immunophenotype but not the IgVH gene sequence had changed during a course of the disease, and MRD could not be followed by flow cytometry. In the remaining cases, the discrepancy was due to a higher sensitivity of ASO‐PCR. Autologous stem cell transplantation resulted in clinical complete response in 87% (20/23) of the patients. By flow cytometry, 35% (8/23) of autotransplanted patients became MRD‐negative, but only 12.5% (2/16) PCR‐negative (sensitivity of ASO‐PCR <0.001 and <0.01, respectively). All allotransplanted patients achieved or maintained hematological CR, and five out of nine patients (56%) became PCR‐negative (sensitivity of PCR between <0.001 and <0.003), two of them having non‐myeloablative conditioning. None of the patients who became PCR‐negative after allogeneic transplantation have relapsed.

Bloodstream infections in acute myeloid leukemia patients treated according to the Finnish Leukemia Group AML-2003 protocol – a prospective nationwide study

Abstract Background: Infections greatly influence the outcome of acute myeloid leukemia (AML) patients receiving intensive treatment. The aim of this study was to establish the incidence, microbial etiology, risk factors and prognosis of bloodstream infections (BSIs) in patients with AML and compare the results with the previous treatment protocol (AML-92). Methods: Registery data were gathered prospectively from 357 patients aged 16–65 years recruited on the AML-2003 treatment protocol between November 2003 and November 2011 during different treatment cycles. Results: Blood culture data were available on 977 treatment episodes, in which there were 503 BSIs (51%). The overall incidence rate (IR) for BSIs (per 1000 hospital days) was 16.7. Twenty patients (5.6%) died due to an infection and 16 of them (80%) had a BSI. The most commonly detected microbes (polymicrobial episodes included) in blood cultures were coagulase-negative staphylococci (CoNS, 24.7%), viridans group streptococci (VGS, 19.1%), enterococci (13.9%) and Enterobacteriacae group (25.9%). The etiology of BSIs varied greatly from treatment cycle to cycle. Conclusions: Enterococcal BSIs have increased compared to our previous treatment protocol, and they represent significant pathogens in blood cultures. Infection-related mortality has decreased despite the increase in the IR of BSIs. Enterococci seem to be an increasingly prominent pathogen underlying BSIs in the AML patients, especially during induction therapy (20%).