Incidence of blast phase in myelofibrosis patients according to anemia severity at ruxolitinib start and during therapy.

BACKGROUND: Anemia is frequently present in patients with myelofibrosis (MF), and it may be exacerbated by treatment with the JAK2-inhibitor ruxolitinib (RUX). Recently, a relevant blast phase (BP) incidence has been reported in anemic MF patients unexposed to RUX. METHODS: The authors investigated the incidence of BP in 886 RUX-treated MF patients, included in the "RUX-MF" retrospective study. RESULTS: The BP incidence rate ratio (IRR) was 3.74 per 100 patient-years (3.74 %p-y). At therapy start, Common Terminology Criteria for Adverse Events grade 3-4 anemia (hemoglobin [Hb] <8 g/dL) and severe sex/severity-adjusted anemia (Hb <8/<9 g/dL in women/men) were present in 22.5% and 25% patients, respectively. IRR of BP was 2.34 in patients with no baseline anemia and reached respectively 4.22, 4.89, and 4.93 %p-y in patients with grade 1, 2, and 3-4 anemia. Considering the sex/severity-adjusted Hb thresholds, IRR of BP was 2.85, 4.97, and 4.89 %p-y in patients with mild/no anemia, moderate, and severe anemia. Transfusion-dependent patients had the highest IRR (5.03 %p-y). Progression-free survival at 5 years was 70%, 52%, 43%, and 27% in patients with no, grade 1, 2, and 3-4 anemia, respectively (p < .001). At 6 months, 260 of 289 patients with no baseline anemia were receiving ruxolitinib, and 9.2% had developed a grade 3-4 anemia. By 6-month landmark analysis, BP-free survival was significantly worse in patients acquiring grade 3-4 anemia (69.3% vs. 88.1% at 5 years, p < .001). CONCLUSIONS: This study highlights that anemia correlates with an increased risk of evolution into BP, both when present at baseline and when acquired during RUX monotherapy. Innovative anemia therapies and disease-modifying agents are warranted in these patients.

Clinical outcomes of ruxolitinib treatment in 595 intermediate-1 risk patients with myelofibrosis: The RUX-MF Real-World Study.

BACKGROUND: Ruxolitinib (RUX) is a JAK1/2 inhibitor approved for the therapy of myelofibrosis (MF) based on clinical trials including only intermediate2-high risk (INT2/HIGH) patients. However, RUX is commonly used in intermediate-1 (INT1) patients, with scarce information on responses and outcome. METHODS: The authors investigated the benefit of RUX in 1055 MF patients, included in the "RUX-MF" retrospective study. RESULTS: At baseline (BL), 595 (56.2%) patients were at INT1-risk according to DIPSS (PMF) or MYSEC-PM (SMF). The spleen was palpable at <5 cm, between 5 and 10 cm, and >10 cm below costal margin in 5.9%, 47.4%, and 39.7% of patients, respectively; 300 (54.1%) were highly symptomatic (total symptom score ≥20). High-molecular-risk (HMR) mutations (IDH1/2, ASXL-1, SRSF2, EZH2, U2AF1Q157) were detected in 77/167 patients. A total of 101 (19.2%) patients had ≥1 cytopenia (Hb < 10 g/dL: n.36; PLT <100 x 109/L: n = 43; white blood cells <4 x 109/L: n = 40). After 6 months on RUX, IWG-MRT-defined spleen and symptoms response rates were 26.8% and 67.9%, respectively. In univariate analysis, predictors of SR at 6 months were no HMR mutations odds ratio [OR], 2.0, p = .05], no cytopenia (OR, 2.10; p = .01), and blasts <1% (OR, 1.91; p = .01). In multivariate analysis, absence of HMR maintained a significant association (OR, 2.1 [1.12-3.76]; p = .01). CONCLUSIONS: In INT1 patients, responses were more frequent and durable, whereas toxicity rates were lower compared to INT2/high-risk patients. Presence of HMR mutations, cytopenia, and peripheral blasts identified less-responsive INT1 patients, who may benefit for alternative therapeutic strategies.

SOHO State of the Art Updates and Next Questions: Chronic Myeloid Leukemia and Pregnancy: "Per Aspera Ad Astra".

Chronic myeloid leukemia (CML) has evolved from an invariably fatal disease to a chronic disorder that can be treated with targeted drugs and allows survival expectations approaching age-matched controls. Thus, pregnancy and conception in CML should not be precluded anymore; however, to ensure the well-being of both the mother and the developing fetus careful planning and management are required. Tyrosine Kinase Inhibitors (TKIs) are not genotoxic or carcinogenic but can pose a risk to the developing fetus, due to their teratogenic potential. The risk depends on the TKI and the stage of fetal development during exposure. Teratogenic risk is high in the first trimester of pregnancy when the baby's organs and structures are forming (5-12 weeks). If a female patient is on therapy it is advisable to stop therapy at the first positive pregnancy test (3-5 weeks) to maximize the length of treatment-free, and ideally to not treat until delivery. If needed, the medication plan during pregnancy may be adjusted. Interferons can be used at any time, imatinib and nilotinib have a reduced placental crossing and could be carefully used after 16 weeks, whereas dasatinib crosses the placenta and can induce problems throughout the whole gestation. Management of pregnancy in CML is complex. This manuscript is an update of the state of the art allowing healthcare providers to be informed of the different situations that can occur and their governance.

A New Algorithm Integrating Molecular Response, Toxicity, and Plasma Level Measures for Ponatinib Dose Choice in Patients Affected by Chronic Myeloid Leukemia.

Ponatinib may be effective in chronic myeloid leukemia (CML) patients after failure of first/second line therapies. Although its efficacy for minimum plasma concentrations (Cmin) is >21.3 ng/mL (equal to 40 nM), ponatinib may cause adverse events (AE) that require dose optimization. The present study was aimed at investigating any possible correlations among ponatinib dose, plasma concentration, molecular response (MR), and tolerability in a real-world setting. Clinical and laboratory records (including MR and drug plasma concentrations) of 32 CML patients treated with ponatinib were harvested and analyzed. Twenty-seven patients (71%) had ponatinib Cmin values > 21.3 ng/mL, but Cmin values > 10.7 ng/mL (considered efficacious in BCR-Abl unmutated patients) were achieved by 80% of the patients receiving ≥30 mg/day and 45% of the subjects treated with 15 mg/day. No significant correlations were identified among clinical efficacy, tolerability, daily dose, and plasma concentration. Notably, patients who underwent dose tapering for tolerability or safety reasons did not experience treatment failure. In a real-world setting, adjustment of ponatinib daily doses lower than those registered may maintain therapeutic efficacy while reducing the risk of vascular events and improving tolerability. Further studies are warranted to confirm the present results in a larger cohort of patients.

Safety and Efficacy of TKIs in very Elderly Patients (≥75 Years) with Chronic Myeloid Leukemia.

BACKGROUND: While the outcomes of chronic phase chronic myeloid leukemia (CP-CML) patients aged over 65 years have been extensively evaluated in real-life experiences, limited data exist for the very elderly population (i.e., aged ≥ 75 years), especially for next-generation tyrosine kinase inhibitors (TKIs). In this retrospective study, we sought to evaluate the safety and efficacy of TKIs in this particular setting of patients. METHODS: We conducted a retrospective analysis of a multicenter cohort of 123 newly diagnosed CP-CML very elderly patients. RESULTS: The median age at diagnosis was 80 years (range: 75-96). In the first line, 86.1% of patients received imatinib, 7.1% dasatinib, 5.6% nilotinib, and 0.81% received bosutinib. A total of 31 patients (25.2%) switched to second-line therapy, nine patients to a third line, and one patient to a fourth line of therapy. Resistance to treatment was the primary reason for switching therapy in both the first (64.5%) and second lines (77.7%). At diagnosis, reduced doses were administered in 36.5% of patients, in 61.2% in the second line, and in all patients in subsequent lines of therapy. In the first-line setting, 71.9% of patients achieved an early molecular response (EMR, i.e., 3-month BCR::ABL1IS < 10%); at 6, 12, and 24 months, MR3 was reached by 35.7%, 55.7%, and 75.0% of patients, respectively, with 16.6%, 35.7%, and 51.7% achieving a deep molecular response (DMR) at the same time points. Treatment-free remission (TFR) was successfully attempted in 11 patients. During the follow-up period, adverse events (AEs) were observed in 78.8% of patients, including 22 cases of cardiovascular AEs. Toxicity grade ≥ 3 was more commonly observed in patients treated with standard doses of TKIs compared to reduced doses (p = 0.033). Overall, the median follow-up was 46.62 months (range: 1.8-206.2), and 43 patients died due to non-CML-related causes. Three patients died due to disease progression to advanced (n = 1) and blastic (n = 2) phases. The 5-year overall survival (OS) for the entire cohort was 71.9% (95% CI: 0.63-0.81), with no significant difference between the patients treated with standard doses of TKIs compared to those treated with reduced doses (p = 0.35). CONCLUSIONS: TKIs appear to be safe and effective even in very elderly CML patients, and dose optimization strategies yield satisfactory molecular responses for adequate disease control with an improved safety profile.

Risk of SARS-CoV-2 infection in patients with hematologic diseases receiving tixagevimab/cilgavimab as pre-exposure prophylaxis in most recent Omicron sublineages era.

OBJECTIVES: Whether pre-exposure prophylaxis (PrEP) with tixagevimab/cilgavimab 150 mg/150 mg (T/C) in individuals with hematologic disease (HD) may lead to a reduced risk of SARS-CoV-2 breakthrough infection (BTI)/hospitalization, or death in the Omicron era remains to be established. METHODS: An observational study included participants with HD who received PrEP. BTIs were defined as SARS-CoV-2 positivity by reverse transcription-polymerase chain reaction. The incidence of BTIs (95% CI) and of BTIs/hospitalization/death was calculated using the Kaplan-Meier method and as the number of BTIs per 100 person-years of follow-up according to the circulating variant of concern (VoC). A Poisson regression model was used to evaluate the association between the rate of incidence and circulating VoCs after controlling for demographics and clinical factors. RESULTS: We included 550 HD patients: 71% initiated T/C PrEP when BA.5 was the most prevalent, followed by XBB/EG, BA.2, and BA.1 (19%, 7%, and 3%, respectively). Overall, the 1-year incidence estimate of BTIs/hospitalization/death was 24% (18.7-29.4%). A greater risk of incident infections was observed when BA.5 and XBB/EG sub-lineages circulated (aRR 5.05 [2.17, 11.77]; P < .001 and 3.82 [1.50, 9.7]; P = 0.005, compared to BA.1, respectively). CONCLUSIONS: The 1-year incidence of SARS-CoV-2 BTIs/hospitalization/death was 24% which is in line with what was observed in other similar studies. The risk appeared to be higher when more recent Omicron sub-lineages were circulating suggesting a reduction of in vitro neutralization.

Efficacy and safety of bosutinib in previously treated patients with chronic myeloid leukemia: final results from the BYOND trial.

This final analysis from the phase 4 BYOND trial reports outcomes with bosutinib in patients with previously treated chronic myeloid leukemia (CML); 163 patients with CML resistant/intolerant to previous tyrosine kinase inhibitors received bosutinib (starting dose: 500 mg QD). At study completion (median follow-up, 47.8 months), 48.1% (n = 75/156) of patients with Philadelphia chromosome-positive chronic phase CML were still receiving treatment. Among evaluable patients, 71.8% (95% CI, 63.9-78.9) and 59.7% (95% CI, 51.4-67.7) attained or maintained major molecular response (MMR) and molecular response (MR)4, respectively, at any time on treatment. The majority of patients achieved a deeper molecular response relative to baseline while on bosutinib. Kaplan-Meier probabilities (95% CI) of maintaining MMR and MR4 at 36 months were 87.2% (78.0-92.7) and 80.7% (69.4-88.1), respectively. At 48 months, the Kaplan-Meier overall survival rate was 88.3% (95% CI, 81.8-92.6); there were 17 deaths, including 2 that were considered CML related. Long-term adverse events (AEs) were consistent with the known safety profile of bosutinib, and no new safety issues were identified. The management of AEs through dose reduction maintained efficacy while improving tolerability. These results support the use of bosutinib in patients with previously treated CML.ClinicalTrials.gov, NCT02228382.

Dose modification dynamics of ponatinib in patients with chronic-phase chronic myeloid leukemia (CP-CML) from the PACE and OPTIC trials.

Ponatinib, the only approved all known-BCR::ABL1 inhibitor, is a third-generation tyrosine-kinase inhibitor (TKI) designed to inhibit BCR::ABL1 with or without any single resistance mutation, including T315I, and induced robust and durable responses at 45 mg/day in patients with CP-CML resistant to second-generation TKIs in the PACE trial. However, cardiovascular toxicities, including arterial occlusive events (AOEs), have emerged as treatment-related AEs within this class of TKIs. The OPTIC trial evaluated the efficacy and safety of ponatinib using a novel, response-based, dose-reduction strategy in patients with CP-CML whose disease is resistant to ≥2 TKIs or who harbor T315I. To assess the dose-response relationship and the effect on the safety of ponatinib, we examined the outcomes of patients with CP-CML enrolled in PACE and OPTIC who received 45 mg/day of ponatinib. A propensity score analysis was used to evaluate AOEs across both trials. Survival rates and median time to achieve ≤1% BCR::ABL1IS in OPTIC were similar or better than in PACE. The outcomes of patients with T315I mutations were robust in both trials. Patients in OPTIC had a lower exposure-adjusted incidence of AOEs compared with those in PACE. This analysis demonstrates that response-based dosing for ponatinib improves treatment tolerance and mitigates cardiovascular risk.

Perspectives on drug development for the treatment of chronic myeloid leukemia in pregnant patients and patients who are breastfeeding.

Tyrosine kinase inhibitors (TKI) have improved the outcome and life expectancy of patients with chronic myeloid leukemia (CML). Patients are diagnosed with CML at younger ages, and patients treated for CML may become pregnant or choose to breastfeed. The information available to date on the safety of TKIs during pregnancy and lactation and the optimal management of these patients is largely anecdotal, based on personal or small-group experience, and heterogeneous. A panel of interested parties was convened by US Food and Drug Administration (FDA) to analyze the current data and discuss possible solutions. Possible solutions include prospective data collection, in clinical trials and in routine clinical practice, a more uniform and specific data collection, and greater coordination among involved entities. Since patients with cancer are living longer, frequently receiving therapies for extended periods of time (or for life), data on appropriate management of patients through different reproductive phases of life are needed. It is thus time to change our approach for how to study treatment of cancer (including CML) during pregnancy or breastfeeding to develop evidence-based guidelines for safe and effective patient care.

Chronic myeloid leukemia diagnosed in pregnancy: management and outcome of 87 patients reported to the European LeukemiaNet international registry.

The management of chronic myeloid leukemia (CML) diagnosed during pregnancy is a rare and challenging situation. We report the treatment and outcome of 87 cases diagnosed in chronic phase from 2001-2022 derived from the largest international observational registry, supported by the European LeukemiaNet (ELN), of 400 pregnancies in 299 CML women. Normal childbirth occurred in 76% without an increased rate of birth abnormalities or life-threatening events, including in patients untreated or treated with interferon-α and/or imatinib in 2nd-3rd trimester. The low birth weight rate of 12% was comparable to that seen in the normal population. Elective and spontaneous abortions occurred in 21% and 3%, respectively. The complete hematologic response rate before labor was 95% with imatinib and 47% with interferon only. No disease progression during pregnancy was observed, 28% of the patients switched their therapy at varying times after delivery. Treatment options balance the efficacy and safety for mother and infant: interferon-α can commence in the 1st trimester and continued throughout in cases of good disease control and tolerability. Because of limited placental crossing, selected tyrosine kinase inhibitors (imatinib and nilotinib) seem to be safe and effective options in 2nd and 3rd trimester while hydroxycarbamide offers few benefits.

The Italian Multicentric Randomized OPTkIMA Trial on Fixed vs Progressive Intermittent TKI Therapy in CML Elderly Patients: 3-Years of Molecular Response and Quality of Life Monitoring After Completing the Treatment Plan.

BACKGROUND: Intermittent treatment with tyrosine kinase inhibitors (TKIs) is an option for elderly chronic myeloid leukemia (CML) patients who are often candidates for life-long treatment. MATERIALS AND METHODS: The Italian phase III multicentric randomized Optimize TKIs Multiple Approaches (OPTkIMA) study aimed to evaluate if a progressive de-escalation of TKIs is able to maintain the molecular remission (MR)3.0 and to improve Health-Related Quality of Life (HRQoL) in CML elderly patients. RESULTS: A total of 215 patients in stable MR3.0/MR4.0 were randomized to receive an intermittent TKI schedule 1 month ON-1 month OFF for 3 years (FIXED arm; n = 111) vs. a progressive de-escalation TKI dose up to one-third of the starting dose at the 3rd year (PROGRESSIVE arm; n = 104). Two hundred three patients completed the 3rd year of OPTkIMA study. At the last follow-up, MR3.0 loss was 27% vs. 46% (P = .005) in the FIXED vs PROGRESSIVE arm, respectively. None of these patients experienced disease progression. The 3-year probability of maintaining the MR3.0 was 59% vs. 53%, respectively (P = .13). HRQoL globally improved from the baseline to the 3rd year, without any significant difference between the 2 arms. After the 3rd year, the proportion of patients who was address to TKI discontinuation in the 2 arms was 36% (FIXED) vs. 58% (PROGRESSIVE) (P = .03). CONCLUSIONS: The intensification of intermittent TKI therapy is associated with a higher incidence of MR3.0 loss, but those patients who maintain the MR3.0 molecular response at the end of the study have been frequently considered eligible for TFR. The HRQoL generally improved during the de-escalation therapy in both randomization arms.

Real World Use of Tixagevimab/Cilgavimab Pre-Exposure Prophylaxis of COVID-19 in Immunocompromised Individuals: Data from the OCTOPUS Study.

Objective. We aimed to report the real-world use and outcomes over time in immunocompromised individuals receiving tixagevimab/cilgavimab (T/C) pre-exposure prophylaxis (PrEP). Methods. This observational study included participants who received T/C PrEP, categorized into three groups: (i) No COVID-19 (NoC), i.e., participants who never had COVID-19; (ii) Hybrids (H), i.e., participants who had COVID-19 before PrEP; and (iii) Break-through Infections (BTIs), i.e., participants who had COVID-19 after PrEP. The study measured several immune markers at the administration of T/C (T0) at 3 (T1), 6 (T2), and 9 (T3) months afterward. These markers included: anti-receptor-binding domain (RBD) IgG antibodies; BA.5-neutralizing antibodies (nAbs); mucosal IgG; and T cell immunity. The incidence rate ratios for BTIs were analyzed using a Poisson regression model. Results. A total of 231 participants with a median age of 63 years (IQR 54.0-73.0). were included. Among these, 84% had hematological diseases and received a median of three vaccine doses. N = 72 participants belonged to the NoC group, N = 103 to the H group, and n = 56 to the BTI group (24%), with most BTIs being mild/moderate. The incidence rate (IR) of BTIs was 4.2 per 100 patient-months (95% CI 3.2-5.4), with no associated risk factors identified. There was a significant increase in anti-RBD IgG levels 3 months after the T/C administration in all groups, followed by a decline at 6 months, whereas at the same time points, geometric mean titers (GMTs) of anti-BA.5 nAbs were low for all groups and were around or below the detection threshold. No significant changes were observed in IFN-γ levels. The mucosal immune response was observed only 3 months after the PrEP administration. Conclusion. We provided a real-world experience model on the clinical efficacy of T/C PrEP in preventing severe COVID-19 during the Omicron wave through a comprehensive virological and immunological study. While waiting for the arrival of new monoclonal antibodies that can effectively neutralize the most recent variants, T/C PrEP remains the only viable strategy in the available armamentarium today to prevent COVID-19 complications in an extremely fragile population with suboptimal immune responses to COVID-19 vaccines.