The analysis of clonal diversity and therapy responses using STAT3 mutations as a molecular marker in large granular lymphocytic leukemia

Peer reviewe

Dasatinib crosses the blood-brain barrier and is an efficient therapy for central nervous system philadelphia chromosome positive leukemia

Although imatinib, a BCR-ABL tyrosine kinase inhibitor, is used to treat acute Philadelphia chromosome-positive (Ph+) leukemia, it does not prevent central nervous system (CNS) relapses resulting from poor drug penetration through the blood-brain barrier. Imatinib and dasatinib (a dual-specific SRC/BCR-ABL kinase inhibitor) were compared in a pre-clinical mouse model of intracranial Ph+ leukemia. Clinical dasatinib treatment in patients with CNS Ph+ leukemia was assessed. In preclinical studies, dasatinib increased survival, whereas imatinib failed to inhibit intracranial tumor growth. Stabilization and regression of CNS disease were achieved with continued dasatinib administration. The drug also demonstrated substantial activity in 11 adult and pediatric patients with CNS Ph+ leukemia. Eleven evaluable patients had clinically significant, long-lasting responses, which were complete in 7 patients. In 3 additional patients, isolated CNS relapse occurred during dasatinib therapy; and in 2 of them, it was caused by expansion of a BCR-ABL-mutated dasatinib-resistant clone, implying selection pressure exerted by the compound in the CNS. Dasatinib has promising therapeutic potential in managing intracranial leukemic disease and substantial clinical activity in patients who experience CNS relapse while on imatinib therapy. This study is registered at ClinicalTrials. gov as CA180006 (#NCT00108719) and CA180015 (#NCT00110097)

RVD induction and autologous stem cell transplantation followed by lenalidomide maintenance in newly diagnosed multiple myeloma: a phase 2 study of the Finnish Myeloma Group

Autologous stem cell transplantation (ASCT) combined with novel agents is the standard treatment for transplant-eligible, newly diagnosed myeloma (NDMM) patients. Lenalidomide is approved for maintenance after ASCT until progression, although the optimal duration of maintenance is unknown. In this trial, 80 patients with NDMM received three cycles of lenalidomide, bortezomib, and dexamethasone followed by ASCT and lenalidomide maintenance until progression or toxicity. The primary endpoint was the proportion of flow-negative patients. Molecular response was assessed if patients were flow-negative or in stringent complete response (sCR). By intention to treat, the overall response rate was 89%. Neither median progression-free survival nor overall survival (OS) has been reached. The OS at 3 years was 83%. Flow-negativity was reached in 53% and PCR-negativity in 28% of the patients. With a median follow-up of 27 months, 29 (36%) patients are still on lenalidomide and 66% of them have sustained flow-negativity. Lenalidomide maintenance phase was reached in 8/16 high-risk patients but seven of them have progressed after a median of only 6 months. In low- or standard-risk patients, the outcome was promising, but high-risk patients need more effective treatment approach. Flow-negativity with the conventional flow was an independent predictor for longer PFS

Chimeric NUP98-NSD1 transcripts from the cryptic t(5;11)(q35.2;p15.4) in adult de novo acute myeloid leukemia

The t(5;11)(q35;p15.4) is a clinically significant marker of poor prognosis in acute myeloid leukemia (AML), which is difficult to detect due to sub-telomeric localization of the breakpoints. To facilitate the detection of this rearrangement, we studied NUP98-NSD1 transcript variants in patients with the t(5;11) using paired-end RNA sequencing and standard molecular biology techniques. We discovered three NUP98-NSD1 transcripts with two fusion junctions (NUP98 exon 11-12/NSD1 exon 6), alternative 5' donor site in NUP98 exon 7, and NSD1 exon 7 skipping. Two of the transcripts were in-frame and occurred in all t(5;11) samples (N=5). The exonic splicing events were present in all samples (N=23) regardless of the NUP98-NSD1 suggesting that these novel splice events are unassociated with t(5;11). In conclusion, we provide evidence of two different NUP98-NSD1 fusion transcripts in adult AML, which result in functional proteins and represent suitable molecular entities for monitoring t(5;11) AML patients.Peer reviewe

RAD50 and NBS1 are breast cancer susceptibility genes associated with genomic instability

The Mre11 complex, composed of RAD50, NBS1 and MRE11, has an essential role in the maintenance of genomic integrity and preventing cells from malignancy. Here we report the association of three Mre11 complex mutations with hereditary breast cancer susceptibility, studied by using a case-control design with 317 consecutive, newly diagnosed Northern Finnish breast cancer patients and 1000 geographically matched healthy controls (P = 0.0004). RAD50 687delT displayed significantly elevated frequency in the studied patients (8 out of 317, OR 4.3, 95% CI 1.5-12.5, P = 0.008), which indicates that it is a relatively common low-penetrance risk allele in this cohort. Haplotype analysis and the screening of altogether 512 additional breast cancer cases from Sweden, Norway and Iceland suggest that RAD50 687delT is a Finnish founder mutation, not present in the other Nordic cohorts. The RAD50 IVS3-1G > A splicing mutation leading to translational frameshift was observed in one patient, and the NBS1 Leu150Phe missense mutation affecting a conserved residue in the functionally important BRCA1 carboxyterminal (BRCT) domain in two patients, both being absent from 1000 controls. Microsatellite marker analysis showed that loss of the wild-type allele was not involved in the tumorigenesis in any of the studied mutation carriers, but they all showed increased genomic instability assessed by cytogenetic analysis of peripheral blood T-lymphocytes (P = 0.006). In particular, the total number of chromosomal rearrangements was significantly increased (P = 0.002). These findings suggest an effect for RAD50 and NBS1 haploinsufficiency on genomic integrity and susceptibility to cancer

RVD induction and autologous stem cell transplantation followed by lenalidomide maintenance in newly diagnosed multiple myeloma:a phase 2 study of the Finnish Myeloma Group

Abstract Autologous stem cell transplantation (ASCT) combined with novel agents is the standard treatment for transplant-eligible, newly diagnosed myeloma (NDMM) patients. Lenalidomide is approved for maintenance after ASCT until progression, although the optimal duration of maintenance is unknown. In this trial, 80 patients with NDMM received three cycles of lenalidomide, bortezomib, and dexamethasone followed by ASCT and lenalidomide maintenance until progression or toxicity. The primary endpoint was the proportion of flow-negative patients. Molecular response was assessed if patients were flow-negative or in stringent complete response (sCR). By intention to treat, the overall response rate was 89%. Neither median progression-free survival nor overall survival (OS) has been reached. The OS at 3 years was 83%. Flow-negativity was reached in 53% and PCR-negativity in 28% of the patients. With a median follow-up of 27 months, 29 (36%) patients are still on lenalidomide and 66% of them have sustained flow-negativity. Lenalidomide maintenance phase was reached in 8/16 high-risk patients but seven of them have progressed after a median of only 6 months. In low- or standard-risk patients, the outcome was promising, but high-risk patients need more effective treatment approach. Flow-negativity with the conventional flow was an independent predictor for longer PFS