Final report of TKI discontinuation trial with dasatinib for the second attempt of treatment-free remission after failing the first attempt with imatinib: Treatment-free Remission Accomplished by Dasatinib (TRAD) study.

Multiple studies have reported a significant treatment-free remission (TFR) rate of 50%-60% in patients with chronic myeloid leukaemia (CML) who discontinue tyrosine kinase inhibitor (TKI) therapy. However, the remaining half of these patients still require re-initiation of TKI therapy for leukaemia control. It remains unclear if TKI drugs should be switched for re-therapy in patients who failed the first TFR (TFR1) attempt. Our study attempted to determine whether dasatinib therapy after TFR1 failure post-imatinib discontinuation could improve the likelihood of TFR2. Of 59 patients who lost molecular response after imatinib discontinuation for TFR1, 55 patients (93.2%) were treated with dasatinib, of whom 49 (89.1%) regained MR4.5 or deeper response, with a median time of 1.85 months to achieve MR4.5. Dasatinib was discontinued in 35 patients for TFR2 attempt, of whom 26 patients (74.28%) lost MMR and 6 (17.14%) MR4. Risk factor analysis for the TFR2 after dasatinib discontinuation suggested three significant factors: (1) doubling time of BCR::ABL1 transcript following TFR1 attempt, (2) rapid regaining of molecular response following dasatinib therapy and (3) undetectable BCR::ABL1 transcript prior to TFR2 attempt. The present study showed that dasatinib does not increase the TFR2 rate in general, but a selected group of patients could benefit from this approach.

PD-L1 expression predicts efficacy in the phase II SPiReL trial with MVP-S, pembrolizumab, and low-dose CPA in R/R DLBCL.

BACKGROUND: Patients with relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) have limited treatment options. METHODS: R/R DLBCL patients, who were mostly ineligible for ASCT due to age or comorbidities, were treated with maveropepimut-S (MVP-S, previously DPX-Survivac) a survivin directed T cell educating therapy, pembrolizumab, and intermittent low-dose cyclophosphamide. FINDINGS: We identified, using univariate analysis, a subset of patients with enhanced ORR, PFS and DOR. Patients with baseline CD20+/PD-L1 expression had an ORR of 46% (6/13) and the disease control rate was 10/13 (77%). The PFS and OS of the positive CD20+/PD-L1 patients were 7.1 months and 17.4 months, whereas in the intent-to-treat (ITT) population of 25 enrolled patients, the ORR was 28% (7/25), median PFS and OS were 4.2 months and 10.1 months respectively. A total of 6/7 clinical responders occurred in CD20+/PD-L1 patients. The regimen was well-tolerated, requiring only minor dose modifications and one discontinuation. Grade 1 or 2 injection site reactions occurred in 14/25, (56%). Statistically significant associations were also seen between PFS and; injection site reactions; and ELISpot response to survivin peptides, both identifying the mechanistic importance of specific immune responses to survivin. INTERPRETATION: This immunotherapy combination was found to be active and safe in this clinically challenging patient population.

BCR-ABL1 transcript doubling time as a predictor for treatment-free remission failure after imatinib discontinuation in chronic myeloid leukaemia in chronic phase.

The doubling time (DT) of the BCR-ABL1 quantitative polymerase chain reaction (qPCR) transcript level reflects the re-growing fraction of leukaemic cells after discontinuation of tyrosine kinase inhibitor (TKI). The present study analyzed monthly DT within six months after imatinib discontinuation in 131 patients. Monthly DT was calculated as x = ln(2)/K, where x is the DT and K is the fold BCR-ABL1 change from the previous value divided by the number of days between each measurement. The optimal DT value was determined as 12·75 days at two months using a recursive partitioning method. The patients were stratified into three groups: the high-risk group (DT<12·75 days but >0, with rapidly proliferating chronic myeloid leukaemia (CML) cells; n = 26) showed the lowest molecular relapse-free survival (mRFS) of 7·7% at 12 months, compared to 53·6% in the intermediate-risk group (DT≥12·75 days, with slowly proliferating CML cells; n = 16) or 90·0% in the low-risk group (DT≤0, i.e., without proliferating CML cells; n = 71; P < 0·001). Monthly assessment of DT helps identify high-risk patients for treatment-free remission failure with an imminent risk of molecular recurrence, and to define low-risk patients who can be spared the frequent monitoring of monthly molecular tests.

Optimal duration of imatinib treatment/deep molecular response for treatment-free remission after imatinib discontinuation from a Canadian tyrosine kinase inhibitor discontinuation trial.

Although total duration of tyrosine kinase inhibitor (TKI) therapy and of molecular response at 4 log reduction or deeper (MR4) correlates with treatment-free remission (TFR) success after TKI discontinuation, the optimal cut-off values of the duration remain unresolved. Thus, 131 patients were enrolled into the Canadian TKI discontinuation study. The molecular relapse-free survival (mRFS) was defined from imatinib discontinuation till molecular recurrence, that is, major molecular response (MMR) loss and/or MR4 loss. We evaluated mRFS at 12 months after imatinib discontinuation, analyzed it according to the imatinib treatment duration and MR4 duration, and calculated P value, positive (PPV) and negative predictive value (NPV) in the yearly cut-off period of time. The shortest cut-off was sought that met the joint criteria of a P value ≤ 0·05, PPV ≥ 60% and NPV ≥ 60%. We propose six years as the shortest imatinib duration cut-off with a P value 0·01, PPV 68% and NPV 62%: The patients treated with imatinib duration ≥ 6 years showed a superior mRFS rate (61·8%) compared to those with less treatment (36·0%). Also, 4·5 years MR4 duration as the shortest cut-off with a P value 0·003, PPV 63% and NPV 61%: those with MR4 duration ≥ 4·5 years showed a higher mRFS rate (64·2%) than those with a shorter MR4 duration (41·9%).

Incidence, outcomes, and risk factors of pleural effusion in patients receiving dasatinib therapy for Philadelphia chromosome-positive leukemia.

Dasatinib, a second-generation BCR-ABL1 tyrosine kinase inhibitor, is approved for the treatment of chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia, both as first-line therapy and after imatinib intolerance or resistance. While generally well tolerated, dasatinib has been associated with a higher risk for pleural effusions. Frequency, risk factors, and outcomes associated with pleural effusion were assessed in two phase 3 trials (DASISION and 034/Dose-optimization) and a pooled population of 11 trials that evaluated patients with chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia treated with dasatinib (including DASISION and 034/Dose-optimization). In this largest assessment of patients across the dasatinib clinical trial program (N=2712), pleural effusion developed in 6-9% of patients at risk annually in DASISION, and in 5-15% of patients at risk annually in 034/Dose-optimization. With a minimum follow up of 5 and 7 years, drug-related pleural effusion occurred in 28% of patients in DASISION and in 33% of patients in 034/Dose-optimization, respectively. A significant risk factor identified for developing pleural effusion by a multivariate analysis was age. We found that overall responses to dasatinib, progression-free survival, and overall survival were similar in patients who developed pleural effusion and in patients who did not. clinicaltrials.gov identifier 00481247; 00123474.

Molecular monitoring of therapeutic milestones and clinical outcomes in patients with chronic myeloid leukemia.

BACKGROUND: In the current study, the authors determined whether adhering to molecular monitoring guidelines in patients with chronic myeloid leukemia (CML) is associated with major molecular response (MMR) and assessed barriers to adherent monitoring. METHODS: Newly treated patients with CML from the Quebec province-wide CML registry from 2005 to 2016 were included. Timely polymerase chain reaction (tPCR) was defined as the molecular assessment of BCR-ABL1 at the 3-month, 12-month, and 18-month time points from the initiation of tyrosine kinase inhibitor (TKI) therapy. The cohort was analyzed as a nested case-control study. Cases with a first-ever MMR (BCR-ABL1 ≤0.1%, assessed at any time during follow-up) were matched to up to 5 controls by duration of TKI therapy, volume of patients with CML at the treatment center, year of cohort entry, and age. Odds ratios (ORs) for the performance of tPCR and MMR were adjusted for sex, comorbidities, type of TKI, and other important covariates. RESULTS: The cohort included 496 patients. Of 392 MMR events, 67.9% occurred before 18 months. The performance of tPCR was associated with a doubling of the MMR rate (OR, 2.23; 95% confidence interval [95% CI], 1.56-3.21) and was similar with 1 to 3 tPCRs performed (P = .67). Furthermore, tPCRs at 3 months (OR, 2.77; 95% CI, 1.81-4.23) and 12 months (OR, 3.00; 95% CI, 1.64-5.49) were associated with achieving early MMR, whereas tPCRs at 18 months were not (OR, 1.23; 95% CI, 0.80-1.89). Low-volume centers were found to have lower adherence to tPCR (OR, 0.60; 95% CI, 0.40-0.89). CONCLUSIONS: Timely molecular assessment at 3 months and 12 months appears to benefit patients with CML. Adherence to timely monitoring should be encouraged, especially in low-volume treatment centers.

Sequencing of high-efficacy disease-modifying therapies in multiple sclerosis: perspectives and approaches.

Multiple sclerosis (MS) is characterized by chronic inflammation in conjunction with neurodegeneration within the central nervous system. Most individuals with MS begin with a relapsing remitting course that later transitions to secondary progressive MS. Currently available disease-modifying therapies (DMTs) for relapsing MS have been demonstrated to reduce disease activity, however most patients require a change in therapy over the course of their disease. Treatment goals include the prevention of relapses and disability accumulation and to achieve this objective requires careful planning. Sequencing of DMTs for individual patients should be designed in such a way to maximize disease control and minimize risk based on the mechanism of action, pharmacokinetic and pharmacodynamic properties of each therapy. This includes the DMT patients are being switched from to those they are being switched to. The reversibility of immune system effects should be a key consideration for DMT sequence selection. This feature varies across DMTs and should factor more prominently in decision making as newer treatments become available for the prevention of disability accumulation in patients with progressive MS. In this short review, we discuss the landscape of existing therapies with an eye to the future when planning for optimal DMT sequencing. While no cure exists for MS, efforts are being directed toward research in neuroregeneration with the hope for positive outcomes.

Sequencing of disease-modifying therapies for relapsing-remitting multiple sclerosis: a theoretical approach to optimizing treatment.

Multiple sclerosis (MS) is a chronic disease which usually begins in young adulthood and is a lifelong condition. Individuals with MS experience physical and cognitive disability resulting from inflammation and demyelination in the central nervous system. Over the past decade, several disease-modifying therapies (DMTs) have been approved for the management of relapsing-remitting MS (RRMS), which is the most prevalent phenotype. The chronic nature of the disease and the multiple treatment options make benefit-risk-based sequencing of therapy essential to ensure optimal care. The efficacy and short- and long-term risks of treatment differ for each DMT due to their different mechanism of action on the immune system. While transitioning between DMTs, in addition to immune system effects, factors such as age, disease duration and severity, disability status, monitoring requirements, preference for the route of administration, and family planning play an important role. Determining a treatment strategy is therefore challenging as it requires careful consideration of the differences in efficacy, safety and tolerability, while at the same time minimizing risks of immune modulation. In this review, we discuss a sequencing approach for treating RRMS, with importance given to the long-term risks and individual preference when devising a treatment plan. Evidence-based strategies to counter breakthrough disease are also addressed.

When to Stop Tyrosine Kinase Inhibitors for the Treatment of Chronic Myeloid Leukemia.

OPINION STATEMENT: Strict criteria for when to stop tyrosine kinase inhibitor (TKI) therapy in clinical practice are not easily defined without an agreement on what probability of achieving a treatment-free remission (TFR) constitutes a medically acceptable standard and consideration of the potential medical risks of continued TKI therapy and/or patient preferences. Patients in sustained deep molecular response (DMR) have no significant chronic myelogenous leukemia-related risk of progression and death, and thus, safety is of paramount importance. Patients with prior history of advanced disease, additional chromosomal abnormalities (ACA), atypical transcripts, TKI resistance, high Sokal score, or who cannot be relied upon to come for regular molecular monitoring should generally be excluded from TKI cessation in clinical practice. Similarly, stopping TKIs should not be attempted without the availability of standardized BCR-ABL1 testing with a sensitivity of at least MR4.5 and a turnaround time of less than 4 weeks. Prior TKI therapy of 5 years and stable MR4.0 of 2 years or more constitutes reasonable minimal criteria for stopping TKIs with approximately a 50% chance of success. The risk of morbidity with continued TKI therapy and patient preferences need to be considered to determine to what extent these minimal criteria should be exceeded and at what threshold to re-initiate therapy whether on the loss of major molecular response or at a lower molecular endpoint.

Immunoablation and autologous haemopoietic stem-cell transplantation for aggressive multiple sclerosis: a multicentre single-group phase 2 trial.

BACKGROUND: Strong immunosuppression, including chemotherapy and immune-depleting antibodies followed by autologous haemopoietic stem-cell transplantation (aHSCT), has been used to treat patients with multiple sclerosis, improving control of relapsing disease. We addressed whether near-complete immunoablation followed by immune cell depleted aHSCT would result in long-term control of multiple sclerosis. METHODS: We did this phase 2 single-arm trial at three hospitals in Canada. We enrolled patients with multiple sclerosis, aged 18-50 years with poor prognosis, ongoing disease activity, and an Expanded Disability Status Scale of 3.0-6.0. Autologous CD34 selected haemopoietic stem-cell grafts were collected after mobilisation with cyclophosphamide and filgrastim. Immunoablation with busulfan, cyclophosphamide, and rabbit anti-thymocyte globulin was followed by aHSCT. The primary outcome was multiple sclerosis activity-free survival (events were clinical relapse, appearance of a new or Gd-enhancing lesion on MRI, and sustained progression of Expanded Disability Status Scale score). This study was registered at ClinicalTrials.gov, NCT01099930. FINDINGS: Between diagnosis and aHSCT, 24 patients had 167 clinical relapses over 140 patient-years with 188 Gd-enhancing lesions on 48 pre-aHSCT MRI scans. Median follow-up was 6.7 years (range 3.9-12.7). The primary outcome, multiple sclerosis activity-free survival at 3 years after transplantation was 69.6% (95% CI 46.6-84.2). With up to 13 years of follow-up after aHSCT, no relapses occurred and no Gd enhancing lesions or new T2 lesions were seen on 314 MRI sequential scans. The rate of brain atrophy decreased to that expected for healthy controls. One of 24 patients died of transplantation-related complications. 35% of patients had a sustained improvement in their Expanded Disability Status Scale score. INTERPRETATION: We describe the first treatment to fully halt all detectable CNS inflammatory activity in patients with multiple sclerosis for a prolonged period in the absence of any ongoing disease-modifying drugs. Furthermore, many of the patients had substantial recovery of neurological function despite their disease's aggressive nature. FUNDING: Multiple Sclerosis Scientific Research Foundation.

Efficacy of Pharmacokinetics-Directed Busulfan, Cyclophosphamide, and Etoposide Conditioning and Autologous Stem Cell Transplantation for Lymphoma: Comparison of a Multicenter Phase II Study and CIBMTR Outcomes.

Busulfan, cyclophosphamide, and etoposide (BuCyE) is a commonly used conditioning regimen for autologous stem cell transplantation (ASCT). This multicenter, phase II study examined the safety and efficacy of BuCyE with individually adjusted busulfan based on preconditioning pharmacokinetics. The study initially enrolled Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) patients ages 18 to 80 years but was amended due to high early treatment-related mortality (TRM) in patients > 65 years. BuCyE outcomes were compared with contemporaneous recipients of carmustine, etoposide, cytarabine, and melphalan (BEAM) from the Center for International Blood and Marrow Transplant Research. Two hundred seven subjects with HL (n = 66) or NHL (n = 141) were enrolled from 32 centers in North America, and 203 underwent ASCT. Day 100 TRM for all subjects (n = 203), patients > 65 years (n = 17), and patients ≤ 65 years (n = 186) were 4.5%, 23.5%, and 2.7%, respectively. The estimated rates of 2-year progression-free survival (PFS) were 33% for HL and 58%, 77%, and 43% for diffuse large B cell lymphoma (DLBCL; n = 63), mantle cell lymphoma (MCL; n = 29), and follicular lymphoma (FL; n = 23), respectively. The estimated rates of 2-year overall survival (OS) were 76% for HL and 65%, 89%, and 89% for DLBCL, MCL, and FL, respectively. In the matched analysis rates of 2-year TRM were 3.3% for BuCyE and 3.9% for BEAM, and there were no differences in outcomes for NHL. Patients with HL had lower rates of 2-year PFS with BuCyE, 33% (95% CI, 21% to 46%), than with BEAM, 59% (95% CI, 52% to 66%), with no differences in TRM or OS. BuCyE provided adequate disease control and safety in B cell NHL patients ≤ 65 years but produced worse PFS in HL patients when compared with BEAM.

Evolving Therapeutic Options for Polycythemia Vera: Perspectives of the Canadian Myeloproliferative Neoplasms Group.

Polycythemia vera (PV) is a clonal stem cell disorder characterized by erythrocytosis and associated with burdensome symptoms, reduced quality of life, risk of thrombohemorrhagic complications, and risk of transformation to myelofibrosis and acute myeloid leukemia. The discovery of the JAK2 V617 mutation marked a significant milestone in understanding the pathophysiology of the disease and subsequently the diagnostic and therapeutic approaches. The current diagnostic criteria for PV are based on hemoglobin level and presence of the JAK2 V617 mutation. The treatment is geared toward prevention of thrombotic events, normalization of blood counts, control of disease-related symptoms, and potential prolongation of survival. Cytoreductive therapy is indicated in patients at increased risk of thrombosis. Hydroxyurea (HU) remains the most commonly used first-line cytoreductive therapy and is superior to phlebotomy in reducing risk of arterial and venous thrombosis. Interferon (IFN) is used either at failure of HU or in selected patients as first-line therapy. The results of pegylated IFN in phase 2 studies appear encouraging, with molecular responses occurring in some patients. Ongoing phase 3 studies of HU versus pegylated IFN will define the optimal first-line cytoreductive therapy for PV. A recent phase 3 trial has shown the superiority of the JAK1/2 inhibitor ruxolitinib in comparison to best available treatment in HU-intolerant or -resistant patients. The therapeutic landscape of PV is likely to change in the near future. In this report, we assess the potential impact of the changing landscape of PV management on daily practice.

The cost-effectiveness of stem cell transplantations from unrelated donors in adult patients with acute leukemia.

OBJECTIVE: Hematopoietic stem cell transplantation is an accepted treatment of hematological malignancies, but the cost-effectiveness of this technology has not been fully explored. This study aims to assess the cost-effectiveness of stem cell transplantation from either cord blood or bone marrow/peripheral blood compared with no transplantation in adult patients with acute leukemias not expected to be cured with chemotherapy. METHODS: A systematic review was performed to estimate the efficacy of unrelated cord blood and bone marrow/peripheral blood stem cells (BM/PBSC) transplantations in adults with acute leukemia. A Markov decision analysis model using Monte Carlo simulations was used to calculate the incremental cost-effectiveness ratio (ICER) and 95% confidence intervals (CIs). RESULTS: The estimated cumulative survival at 1 and 10 years were 27.9% and 14%, respectively, for cord blood recipients and 47% and 17.7%, respectively, for BM/PBSC recipients. Using conservative assumptions, the cost per life-year gained compared with no transplantation was US 16,346 dollars (95% CI 8695 dollars, 38,006 dollars) for BM/PBSC transplantation and US 34,360 dollars (95% CI 23,101 dollars, 89,417 dollars) for cord blood transplantation. CONCLUSIONS: Although both types of stem cell transplantations are associated with a high short-term mortality and high cost, the cumulative gains in life-years of survivors can be substantial, resulting in ICERs compared with no transplantation that are usually considered acceptable. However there is less certainty about this conclusion with cord blood transplantation.