Maryse M. Power

Cytogenetic and molecular responses to standard-dose imatinib in chronic myeloid leukemia are correlated with Sokal risk scores and duration of therapy but not trough imatinib plasma levels.

Cytogenetic and molecular responses to standard-dose imatinib (IM) were correlated with trough IM plasma levels for 78 patients with chronic myeloid leukemia (CML) after a minimum of 12 months of IM therapy. The mean trough IM plasma level was 1065 ng/ml (range, 203-2910). There was no correlation of mean plasma trough IM levels and complete cytogenetic response (CCR) at 1 year (CCR 1010 ng/ml vs no CCR 1175 ng/ml P=.29) or major molecular response (MMR) (MMR1067 ng/ml vs no MMR 1063 ng/ml P=.74) after a median of 1298 days of IM therapy. CCR and MMR did correlate with Sokal risk scores with the odds of achieving CCR or MMR for a low risk vs high risk score of 10.8 (95% CI 2.2-53.5) and 6.4 (95% CI 1.4-29.4), respectively. Furthermore, a longer duration of IM therapy also was associated with a greater likelihood of achieving MMR (P=.02).

Novel agents improve survival of transplant patients with multiple myeloma including those with high-risk disease defined by early relapse (<12 months)

The treatment of multiple myeloma (MM) has changed with the advent of thalidomide, bortezomib, and lenalidomide, the so-called novel agents (NAs). Given the complexity of MM therapy in the NA era we pursued a population based study to assess for improvements in survival as well as to characterize the relevance of early relapse (within 12 months) and the International Staging System in this clinical setting. We reviewed our experience with 460 patients with MM treated with autologous stem cell transplant (ASCT) between 1988 and 2008, of whom 306 had relapsed. The cohort was divided into two groups based upon relapse pre-2004 and relapse during/after 2004 (2004+), which correlated to availability of bortezomib and lenalidomide. Improvements in both overall survival (OS) (median 32.0 months vs. 71.8 months; pu200a<u200a0.001) and post-relapse survival (PRS) (median 15.2 months vs. 42.8 months; pu200a<u200a0.001) correlated with the NA era. Exposure to NAs conferred a better PRS (median 35.7 months vs. 9.1 months; pu200a<u200a0.001). Although all patients had improvements in survival, those who relapsed late continued to do better. Lastly, in the NA era, the ISS remains an important prognostic tool in relapse, but only in the late relapsing cohort.

A Novel Prognostic Model Based on Tumor Microenvironment Biology in Relapse Biopsies Predicts Post-Autologous Stem Cell Transplantation Outcomes in Classical Hodgkin Lymphoma

Pediatric-type nodal follicular lymphoma (PTNFL) is a variant of follicular lymphoma (FL) characterized by limited-stage presentation and invariably benign behavior despite often high-grade histological appearance. It is important to distinguish PTNFL from typical FL in order to avoid unnecessary treatment; however, this distinction relies solely on clinical and pathological criteria, which may be variably applied. To define the genetic landscape of PTNFL, we performed copy number analysis and exome and/or targeted sequencing of 26 PTNFLs (16 pediatric and 10 adult). The most commonly mutated gene in PTNFL was MAP2K1, encoding MEK1, with a mutation frequency of 43%. All MAP2K1 mutations were activating missense mutations localized to exons 2 and 3, which encode negative regulatory and catalytic domains, respectively. Missense mutations in MAPK1 (2/22) and RRAS (1/22) were identified in cases that lacked MAP2K1 mutations. The second most commonly mutated gene in PTNFL was TNFRSF14, with a mutation frequency of 29%, similar to that seen in limited-stage typical FL (P = .35). PTNFL was otherwise genomically bland and specifically lacked recurrent mutations in epigenetic modifiers (eg, CREBBP, KMT2D). Copy number aberrations affected a mean of only 0.5% of PTNFL genomes, compared with 10% of limited-stage typical FL genomes (P < .02). Importantly, the mutational profiles of PTNFLs in children and adults were highly similar. Together, these findings define PTNFL as a biologically and clinically distinct indolent lymphoma of children and adults characterized by a high prevalence of MAPK pathway mutations and a near absence of mutations in epigenetic modifiers.

Response to Tyrosine Kinase Inhibitor Therapy in Patients with Chronic Myelogenous Leukemia Relapsing in Chronic and Advanced Phase Following Allogeneic Hematopoietic Stem Cell Transplantation

Tyrosine kinase inhibitors (TKI) have been used to treat relapse of chronic myelogenous leukemia (CML) after allogeneic stem cell transplant (HSCT), with responses seen predominantly in chronic phase (CP) patients. This study aimed to analyze the response to TKI therapy and overall survival for patients relapsing predominantly in advanced phase. We retrospectively reviewed 22 patients treated with imatinib (n=20) and/or dasatinib (n=6) for relapsed CML after HSCT; 8 patients were in CP, and 14 patients had advanced disease. Seven patients also received donor lymphocyte infusions. Hematologic, cytogenetic, and molecular responses were analyzed. Nineteen patients (86%) achieved complete hematologic response (CHR), 17 patients (77%) achieved complete cytogenetic response (CCR), and 14 patients (64%) achieved complete molecular response (CMR). In advanced phase patients, 11 (79%) achieved CHR, 10 (71%) CCR, and 8 (57%) achieved CMR. Grade 3 or 4 cytopenias occurred in 10 cases. With median follow-up of 31.5 months from relapse, 14 (64%) patients remain alive, 13 in CMR. In multivariate analysis, the achievement of CMR was significantly correlated with OS with an odds ratio of 20.5 (95% confidence interval 2.3-182) P=.007. TKI therapy is capable of inducing durable molecular responses for CML relapsing after HSCT, both in chronic and advanced phases. The achievement of CMR appears to be crucial in providing long-term disease control for these patients.

Chemoresistance can be overcome with high-dose chemotherapy and autologous stem-cell transplantation for relapsed and refractory Hodgkin lymphoma

BACKGROUNDnHigh-dose therapy and autologous stem-cell transplant (HDT/ASCT) is the preferred treatment of chemosensitive relapsed/refractory Hodgkin lymphoma (HL). The role for HDT/ASCT in chemoresistant HL is less well defined. We evaluated long-term outcomes of relapsed/refractory HL patients whose disease was refractory to secondary chemotherapy preceding HDT/ASCT.nnnPATIENTS AND METHODSnAll HL patients who underwent HDT/ASCT in British Columbia for primary progression (PP, defined as progression within 3 months of initial therapy completion) or first relapse (REL1) were reviewed. Patients were grouped based on response to secondary chemotherapy as sensitive (S), resistant (R), and untested/unknown (U).nnnRESULTSnA total of 256 patients underwent HDT/ASCT for PP (35%) or REL1 (65%) between 1985 and 2011. At median follow-up of 11.7 years, 58% were alive without HL, 36% relapsed; 6% died of transplant-related mortality, 3% secondary malignancies, and 3% unrelated causes. For PP/S, PP/R, and PP/U groups, 10-year FFS were 47%, 31%, and 38%; 10-year OS were 52%, 29%, and 37%, respectively. For REL1/S, REL1/R, and REL1/U groups, 10-year FFS were 64%, 51%, and 81%; 10-year OS were 71%, 59%, and 79%, respectively. In multivariate analysis, resistance to secondary chemotherapy predicted for post-transplant mortality in the PP (P = 0.04) but not REL1 (P = 0.16) groups.nnnCONCLUSIONnIn this large uniformly treated cohort of HL patients with long-term follow-up, chemoresistance preceding HDT/ASCT was identified as a poor prognostic factor; however, this factor can be partially overcome by HDT/ASCT, resulting in cure in 30%-50% of patients. HDT/ASCT should therefore be considered in all transplant eligible patients, regardless of responsiveness to salvage chemotherapy.

Allogeneic haematopoietic stem cell transplantation for chronic lymphocytic leukaemia: outcome in a 20‐year cohort

The curative potential of allogeneic haematopoietic stem cell transplant (allo HSCT) in chronic lymphocytic leukaemia CLL is established, with a demonstrated role for graft‐versus‐leukaemia and less certainty for other factors in determining outcome. The first two decades of CLL patients proceeding to allo HSCT at the Leukaemia/Bone Marrow Transplant Program of British Columbia (n = 49 consecutive, 1991–2009) were studied to clarify factors predicting outcome. The donor was related in 29 (59%) and unrelated in 20 (41%). Conditioning was reduced‐intensity in 27 (55%) and myeloablative in 22 (45%). Thirty‐one of 49 patients survive with median follow‐up of 5 years (0·2–15). Cumulative incidence of non‐relapse mortality; complete remission (CR); clearance of fluorescence in situ hybridization (FISH) abnormality and progression at 10 years was 36%; 69%; 55% and 22%. Overall survival (OS) was 63% at 2 years; 55% at 5 years and beyond. Factors predicting OS (P value by log rank <0·05) were: comorbidity index <3, FISH rank (Dohner) and 17p deletion, alemtuzumab pre‐HSCT, achievement of CR post‐HSCT, donor chimerism >90%, clearance of FISH abnormality post‐HSCT and absence of high‐grade (3–4) graft‐versus‐host disease. Results from this province‐wide, two‐decade cohort demonstrated that a substantial proportion of patients with high‐risk CLL become long term disease‐free survivors.

Outcome of Patients With Non-Hodgkin Lymphomas With Concurrent MYC and BCL2 Rearrangements Treated With CODOX-M/IVAC With Rituximab Followed by Hematopoietic Stem Cell Transplantation

BACKGROUNDnDouble-hit lymphoma is characterized by the presence of concurrent MYC (myelocytomatosis oncogene) and BCL2 (B-cell lymphoma 2) gene rearrangements. Prognosis is poor with standard chemoimmunotherapy. Since 2003, the British Columbia Cancer Agency has used CODOX-M/IVAC+R (cyclophosphamide, vincristine, doxorubicin, methotrexate, cytarabine, ifosfamide, and etoposide, combined with rituximab) followed by consolidative hematopoietic cell transplantation as definitive treatment for double-hit lymphoma.nnnPATIENTS AND METHODSnA retrospective review of the survival outcomes of patients with double-hit lymphoma treated at our institution was conducted. Thirty-two patients diagnosed with non-Hodgkin lymphoma with concurrent MYC and BCL2 translocations from 2003 to 2013 were identified. Cases with MYC or BCL2 amplification and those with overexpression in immunohistochemistry analysis were excluded.nnnRESULTSnMedian age at diagnosis was 53.0 years (range, 35.5-70.9 years), 23 (72%) were male, and 30 (94%) had stage III to IV disease. CODOX-M/IVAC+R was administered in 25 (78%) patients and 20 (80%) achieved a partial remission or better, of which 9 (36%) had a complete remission. Nineteen of the 32 (59%) patients underwent upfront hematopoietic cell transplantation. At a median follow-up of living patients of 26.4 months, 14 (44%) were alive in remission, 15 (47%) died, and 3 (9%) were alive in relapse. The 2-year progression-free survival (PFS) and overall survival (OS) of all patients were 41% and 53%, respectively. The sixteen patients treated with CODOX-M/IVAC+R followed by hematopoietic cell transplantation had a 2-year PFS of 60% and 2-year OS of 82%.nnnCONCLUSIONnPatients with double-hit lymphoma treated with CODOX-M/IVAC+R followed by hematopoietic cell transplantation can achieve durable remissions, although disease progression before transplantation remains a significant problem.

IPSS Poor-Risk Karyotype as a Predictor of Outcome for Patients with Myelodysplastic Syndrome following Myeloablative Stem Cell Transplantation

The optimal therapy for myelodysplastic syndrome (MDS) is allogeneic bone marrow (BM) or blood (BSC) stem cell transplantation (SCT), although outcomes are limited by nonrelapse mortality (NRM) and relapse. A retrospective review was performed of 156 patients who underwent SCT (114 BM, 42 BSC) for MDS or secondary acute myelogenous leukemia (sAML) at our institution. Fifty-five patients remain in continuous complete remission: 35 BM recipients and 20 BSC recipients (median follow-up 139 and 89 months, respectively). Estimated 7-year event-free survival (EFS), NRM, and risk of relapse (ROR) are 33% (95% confidence intervals [CI] 25%-43%), 42% (CI 33%-51%), and 25% (CI 17%-33%) for the BM cohort and 45% (CI 32%-64%, P= .07), 32% (CI 18%-47%, P= .15), and 23% (CI 11%-37%, P= .79) for the BSC cohort. Multivariate analysis showed IPSS poor-risk cytogenetics (P< .001), time from diagnosis to SCT (P< .001), FAB subgroup (P= .001), recipients not in complete remission (CR1) at SCT (P= .005), and the development of acute graft-versus-host disease (aGVHD) (P= .04) were all predictive of an inferior EFS. The FAB subgroup (P= .002), poor-risk karyotype (P= .004), and non-CR1 status also correlated with ROR in multivariate analysis. EFS for poor-risk karyotype patients was superior after receiving BSC compared to BM (39% versus 6%, P< .001). SCT outcomes in MDS/sAML are strongly associated with the IPSS cytogenetic risk group, although the use of BSC in poor-risk karyotype patients may lead to a more favorable long-term EFS.

Long-term follow-up of patients with chronic myeloid leukemia in chronic phase developing sudden blast phase on imatinib therapy

Abstract Sudden blast phase (SBP) is a rare event that occurs in an unpredictable fashion amongst patients with chronic myeloid leukemia (CML) who otherwise appear to be responding satisfactorily to imatinib (IM) treatment. We investigated the incidence, clinical characteristics, treatment outcome and long-term follow-up of 213 patients with chronic phase CML treated with IM according to the European LeukemiaNet guidelines. Nine patients, eight of whom received IM as first-line therapy, developed SBP (4.2% of the total). They tended to have low or intermediate risk Sokal scores at diagnosis, a predominance of the lymphoid phenotype and a short interval from “optimal” response to the development of BP. Five of the nine patients with SBP are alive in complete molecular remission; however, all of them underwent allogeneic hematopoietic stem cell transplant. The cumulative incidence of SBP for the patients who received IM as first-line therapy was 5.9% and the 2-year overall survival of the nine patients who developed SBP was 56%. Despite the improved outcome for patients with SBP receiving tyrosine kinase inhibitors (TKIs) and transplant, many of these patients are not salvaged with these therapies. This illustrates the need to develop predictive models to identify patients early whose response to TKI therapy will not be durable and hopefully prevent the transformation to advanced disease.

Gemcitabine, dexamethasone, and cisplatin (GDP) is an effective and well-tolerated salvage therapy for relapsed/refractory diffuse large B-cell lymphoma and Hodgkin lymphoma

Abstract The optimal choice of salvage therapy for patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) or Hodgkin lymphoma (HL) remains unknown. Based on promising results of phase II trials, the preferred salvage regimen in British Columbia since 2002 has been the out-patient regimen, gemcitabine, dexamethasone, and cisplatin (GDP). We conducted a retrospective analysis including all patients with relapsed/refractory DLBCL or HL who received GDP as salvage therapy between September 2002 and June 2010. We identified 235 patients: 152 DLBCL, 83u2009HL. Overall response rates were 49% and 71% for patients with DLBCL and HL, respectively. Within the transplant-eligible population, 52% of patients with DLBCL and 96% of patients with HL proceeded to stem cell transplantation. The 2-year progression-free survival and overall survival were 21% and 28% in the DLBCL cohort, and 58% and 85% in the HL group. GDP is an effective and well-tolerated out-patient salvage regimen for relapsed/refractory DLBCL and HL.