Does IPSS-R downstaging before transplantation improve the prognosis of patients with myelodysplastic neoplasms?

ABSTRACT: In patients with myelodysplastic syndrome (MDS), higher revised International Prognostic Scoring System (IPSS-R) scores at transplant are associated with worse transplant outcome and, thus, lowering IPSS-R scores by therapeutic intervention before transplantation may seem beneficial. However, there is no evidence, to date, to support this approach. In a retrospective analysis, a total of 1482 patients with MDS with sufficient data to calculate IPSS-R score at diagnosis and at time of transplantation were selected from the European Society for Blood and Marrow Transplantation transplant registry and analyzed for transplant outcome in a multivariable Cox model including IPSS-R score at diagnosis, treatment intervention, change in IPSS-R score before transplant, and several patient and transplant variables. Transplant outcome was unaffected by IPSS-R score change in untreated patients and moderately superior in patients treated with chemotherapy with improved IPSS-R score at transplant. Improved IPSS-R score after hypomethylating agents (HMAs) or other therapies showed no beneficial effect. However, when IPSS-R score progressed after chemotherapy, HMAs, or other therapies, transplant outcome was worse than without any prior treatment. Similar results were found when reduction or increase in bone marrow (BM) blasts between diagnosis and transplantation was considered. The results show a limited benefit of IPSS-R score downstaging or reduction of BM blasts after chemotherapy and no benefit for HMAs or other treatments and thus question the role of prior therapy in patients with MDS scheduled for transplantation. The model-based survival estimates should help inform decision-making for both doctors and patients.

Prediction of sustained remission after tyrosine kinase inhibitor discontinuation with BCR::ABL1 digital PCR in chronic myeloid leukemia patients.

Precise and reliable predictive parameters to accurately identify chronic myeloid leukemia (CML) patients who can successfully discontinue their tyrosine kinase inhibitor (TKI) treatment are lacking. One promising parameter is depth of molecular response measured by BCR::ABL1 digital PCR (dPCR). The aim of this study was to validate a previously described prediction cutoff of 0.0023%IS and to assess the value of dPCR for treatment-free remission (TFR) prediction in relation to other clinical parameters. A droplet-based dPCR assay assessed BCR::ABL1 %IS prior to TKI discontinuation. The primary endpoint was molecular recurrence (MolR) by 36 months. A total of 186 patients from Canada, Germany, and the Netherlands were included. In patients with a first TKI discontinuation attempt (n = 163), a BCR::ABL1 dPCR < and ≥0.0023%IS had a MolR probability of 33% and 70%, respectively. Patients treated less than 6 years with a BCR::ABL1 dPCR <0.0023%IS had a MolR probability of 31%. After correction for treatment duration, both high dPCR value and the use of imatinib (vs. second-generation TKI) were significantly associated with a higher risk of MolR (HR of 3.66, 95%CI 2.06-6.51, p < .001; and 2.85, 95%CI 1.25-6.46, p = .013, respectively). BCR::ABL1 dPCR was not associated with TFR outcome after second TKI discontinuation, however, with the limitation of a small number of patients analyzed (n = 23). In conclusion, BCR::ABL1 digital PCR based on the cutoff of 0.0023%IS is a valuable predictive tool to identify CML patients with a high probability of TFR success after first TKI discontinuation, including patients treated for less than 6 years.

Attitudes of healthcare professionals and drug regulators about progression-free survival as endpoint in the advanced cancer setting.

PURPOSE: To describe the attitudes of healthcare professionals and drug regulators about progression-free survival (PFS) as efficacy endpoint in clinical trials with patients with advanced cancer and to explore to what extent these attitudes influence the willingness to trade between PFS and toxicity. METHODS: Cross-sectional survey with regulators from the European Medicines Agency (EMA), and healthcare professionals (HCP) from the "Stichting Hemato-Oncologie voor Volwassenen Nederland" (HOVON) collaborative group and the European Organisation for Research and Treatment of Cancer (EORTC). Attitudes towards PFS were elicited using 5-point Likert items. The respondents' willingness to trade between PFS and grade 3 or 4 (G34) toxicity was assessed using the threshold technique and quantified in terms of their maximum acceptable risk (MAR). RESULTS: Responses were collected from 287 HCPs and 64 regulators with mainly clinical expertise. Attitudes towards PFS were often spread out in both groups and related to beliefs about PFS being a likely surrogate for clinical benefit, being an intrinsic benefit to be distinguished from OS, or on the importance given to OS. Being a regulator or holding stronger beliefs about PFS being a likely surrogate or an intrinsic benefit were associated with a higher MAR. Presence of a supportive trend in OS was stated as important but was not associated with MAR. There was agreement on the need to address bias in the adjudication of PFS and the need for improving communication to patients about meaning, strengths, and limitations of improvements in PFS. CONCLUSION: Attitudes towards PFS were spread out and were associated with individual differences in the willingness to trade between toxicity and PFS. There was agreement on the need to address bias in the adjudication of PFS and improving communication to patients.

Bayesian interim analysis for prospective randomized studies: reanalysis of the acute myeloid leukemia HOVON 132 clinical trial.

Randomized controlled trials (RCTs) are the gold standard to establish the benefit-risk ratio of novel drugs. However, the evaluation of mature results often takes many years. We hypothesized that the addition of Bayesian inference methods at interim analysis time points might accelerate and enforce the knowledge that such trials may generate. In order to test that hypothesis, we retrospectively applied a Bayesian approach to the HOVON 132 trial, in which 800 newly diagnosed AML patients aged 18 to 65 years were randomly assigned to a "7 + 3" induction with or without lenalidomide. Five years after the first patient was recruited, the trial was negative for its primary endpoint with no difference in event-free survival (EFS) between experimental and control groups (hazard ratio [HR] 0.99, p = 0.96) in the final conventional analysis. We retrospectively simulated interim analyses after the inclusion of 150, 300, 450, and 600 patients using a Bayesian methodology to detect early lack of efficacy signals. The HR for EFS comparing the lenalidomide arm with the control treatment arm was 1.21 (95% CI 0.81-1.69), 1.05 (95% CI 0.86-1.30), 1.00 (95% CI 0.84-1.19), and 1.02 (95% CI 0.87-1.19) at interim analysis 1, 2, 3 and 4, respectively. Complete remission rates were lower in the lenalidomide arm, and early deaths more frequent. A Bayesian approach identified that the probability of a clinically relevant benefit for EFS (HR < 0.76, as assumed in the statistical analysis plan) was very low at the first interim analysis (1.2%, 0.6%, 0.4%, and 0.1%, respectively). Similar observations were made for low probabilities of any benefit regarding CR. Therefore, Bayesian analysis significantly adds to conventional methods applied for interim analysis and may thereby accelerate the performance and completion of phase III trials.

Impact of the Type of Tyrosine Kinase Inhibitor (imatinib or dasatinib) Used Before allo-HCT on Outcome of Patients with Philadelphia-Positive Acute Lymphoblastic Leukemia. A Study on Behalf of the Acute Leukemia Working Party of the EBMT.

The use of tyrosine kinase inhibitors (TKIs) during induction and consolidation, followed by allogeneic hematopoietic cell transplantation (allo-HCT), is a standard of care for patients with Philadelphia (Ph)-positive acute lymphoblastic leukemia (ALL). The goal of this study was to compare results of allo-HCT according to the type of TKI used pre-transplant, either imatinib, dasatinib or both. This was a retrospective, registry-based analysis including adult patients with Ph-positive ALL treated with allo-HCT between years 2010-2022. The analysis included 606 patients pre-treated with imatinib, 163 with dasatinib and 94 with both imatinib and dasatinib. Allo-HCTs were performed in first complete remission from either unrelated (56%), matched sibling (36%) or haploidentical donors (8%). Relapse incidence at 2 years was 26% in the imatinib group and 21% in the dasatinib group and 19% in the imatinib + dasatinib group (P = .06) while non-relapse mortality was 19%, 15%, and 23%, respectively (P = .37). No significant differences were found for leukemia-free survival (55% vs. 63% vs. 58%, P = .11) and overall survival (72% vs. 76% vs. 65%, P = .32). The incidence of grade 2-4 acute graft-versus-host disease (GVHD) and chronic GVHD was comparable across study groups, while the incidence of grade 3-4 acute GVHD was significantly increased for patients pre-treated with dasatinib alone (20%) than in the imatinib group (10%) or imatinib + dasatinib group (13%) (P = .002). On multivariate analysis a chance of GVHD and relapse-free survival (GRFS) was significantly decreased while the risk of grade 3-4 acute GVHD was increased for the dasatinib compared to imatinib group (hazard ratio, HR = 1.27, P = .048 and HR = 2.26, P = .0009, respectively). This study provides no evidence for the advantage of one TKI over another in terms of LFS and OS. However, the use of dasatinib is associated with increased risk of severe acute GVHD and decreased GRFS.

Benefits and risks of clofarabine in adult acute lymphoblastic leukemia investigated in depth by multi-state modeling.

BACKGROUND: We recently reported results of the prospective, open-label HOVON-100 trial in 334 adult patients with acute lymphoblastic leukemia (ALL) randomized to first-line treatment with or without clofarabine (CLO). No improvement of event-free survival (EFS) was observed, while a higher proportion of patients receiving CLO obtained minimal residual disease (MRD) negativity. AIM: In order to investigate the effects of CLO in more depth, two multi-state models were developed to identify why CLO did not show a long-term survival benefit despite more MRD-negativity. METHODS: The first model evaluated the effect of CLO on going off-protocol (not due to refractory disease/relapse, completion or death) as a proxy of severe treatment-related toxicity, while the second model evaluated the effect of CLO on obtaining MRD negativity. The subsequent impact of these intermediate events on death or relapsed/refractory disease was assessed in both models. RESULTS: Overall, patients receiving CLO went off-protocol more frequently than control patients (35/168 [21%] vs. 18/166 [11%], p = 0.019; HR 2.00 [1.13-3.52], p = 0.02), especially during maintenance (13/44 [30%] vs. 6/56 [11%]; HR 2.85 [95%CI 1.08-7.50], p = 0.035). Going off-protocol was, however, not associated with more relapse or death. Patients in the CLO arm showed a trend towards an increased rate of MRD-negativity compared with control patients (HR MRD-negativity: 1.35 [0.95-1.91], p = 0.10), which did not translate into a significant survival benefit. CONCLUSION: We conclude that the intermediate states, i.e., going off-protocol and MRD-negativity, were affected by adding CLO, but these transitions were not associated with subsequent survival estimates, suggesting relatively modest antileukemic activity in ALL.

Isocitrate dehydrogenase (IDH) 1 and 2 mutations predict better outcome in patients with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplantation: a study of the ALWP of the EBMT.

Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) mutations have uncertain prognostic implications in AML. We investigate the impact IDH1 and IDH2 mutations in AML patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) in first complete remission (CR1). In total, 1515 adult patients were included, 15.91% (n = 241) carried IDH1 mutation (mIDH1), and 26.27% (n = 398) IDH2 mutation (mIDH2) and 57.82% (n = 876) had no-IDH mutation. NPM1 was frequently encountered with IDH1 mutation (no-IDH group, n = 217, 24.8%, mIDH1, n = 103, 42.7%, mIDH2, n = 111, 27.9%, p < 0.0001). At day 180, the cumulative incidence (CI) of grade II-IV acute graft-versus-host disease (GVHD) was significantly lower in mIDH1 and mIDH2 compared to no-IDH groups (Hazard ratio [HR] = 0.66 (95% CI 0.47-0.91), p = 0.011; HR = 0.73 (95% CI 0.56-0.96), p = 0.025, respectively). In the mIDH1 group, overall survival (OS) was improved compared to no-IDH (HR = 0.68 (95% CI 0.48-0.94), p = 0.021), whereas mIDH2 was associated with lower incidence of relapse (HR = 0.49 (95% CI 0.34-0.7), p < 0.001), improved leukemia free survival (LFS) (HR = 0.7 (95% CI 0.55-0.9), p = 0.004) and OS (HR = 0.74 (95% CI 0.56-0.97), p = 0.027). In the subgroup of NPM1 wild type, only IDH2 was associated with improved outcomes. In conclusion, our data suggest that IDH1 and IDH2 mutations are associated with improved outcomes in patients with AML undergoing allo-HCT in CR1.