Autologous stem cell transplantation in favorable-risk acute myeloid leukemia: single-center experience and current challenges.

BACKGROUND: Autologous stem cell transplantation (ASCT) has gained growing consideration as a treatment option for favorable-risk acute myeloid leukemia (FR-AML) in first complete remission (CR1), compared with chemotherapy. MATERIALS AND METHODS: We report the long-term outcomes of 117 consecutive patients with FR-AML fit for intensive chemotherapy diagnosed in our center between 1999 and 2020, who underwent ASCT. RESULTS: Sixty-five of the 117 were eligible for intensive post-remission treatment, and 42 of those 65 received ASCT. Median follow up was 132 months. Overall survival (OS) and disease-free survival (DFS) were 75% and 76%. Higher doses of CD34 + stem cell infusions negatively impacted DFS in multivariate analysis. Core-binding factor (CBF) leukemia was an independent prognostic factor for improved DFS. No differences based on pre-transplant measurable residual disease (MRD) were observed. In CBF leukemia, 10-year DFS is 72% for MRD-positive patients versus 100% for MRD negative patients. CONCLUSIONS: ASCT is effective and safe in FR-AML patients. In CBF leukemia, ASCT provides excellent results regardless of achievement of bone marrow MRD negativity. In NPM1-mutated/FLT3-wild type (mNPM1) AML, early molecular response seems to have more impact on prognosis. Prospective investigation of the role of gemtuzumab ozogamicin in this setting is ongoing.

Myeloid Sarcoma: Diagnostic and Treatment Tools from a Monocentric Retrospective Experience.

Myeloid sarcoma (MS) is a very rare disease in both adults and children. Prognosis is poor in adults; in the pediatric age, the prognostic impact of extramedullary disease is controversial. Systemic therapy represents the mainstay of treatment even in isolated MS, but a comparison between different induction regimens is very limited in the literature. To date, it is still not clear if induction treatment should differ from that of other acute myeloid leukemias and stem cell transplant is considered for consolidation in both leukemic patients and in those with isolated disease. Our study describes a retrospective series of 13 cases of MS (adults and children), diagnosed and treated at our institute over 18 years. We report the results of immunophenotypic, cytogenetic and molecular studies, therapeutic approaches, and outcome, in order to establish the best strategy for patients' workup.

Long-term follow-up of late chronic phase chronic myeloid leukemia patients treated with imatinib after interferon failure: a single center experience.

We report the long-term outcome of 139 patients treated with imatinib in late chronic phase after IFN failure. Median follow-up was 16.6 years and the estimated 18-year OS was 64.8%. 18-year EFS and PFS were 69% and 64.4%, respectively. Fifty (36%) patients stopped imatinib, 72% received a second line. b2a2 transcript was associated with a significantly inferior 18-year OS (p = 0.008), FFS (p = 0.036), PFS (p = 0.013) compared to the b3a2 type, whilst the type of transcript did not influence the time to response achievement. Failure to achieve MMR at 12 months significantly reduced the chance of reaching a DMR (p = 0.001). Imatinib discontinuation after achieving a sustained deep molecular response was attempted in 14 patients; 12 (86%) are still in treatment-free remission (TFR) at the last follow-up. Our experience confirms the long-term efficacy of imatinib after IFNα failure in real-life setting and documents the possibility of attempting a TFR in this subset of patients.

Real-life comparison of nilotinib versus dasatinib as second-line therapy in chronic phase chronic myeloid leukemia patients.

Tyrosine kinase inhibitors (TKIs), the backbone of treatment for chronic phase chronic myeloid leukemia patients (CP-CML), have changed the long-term outcome of the disease. Nonetheless, over 20% of patients fail front-line therapy due to intolerance or resistance. A head-to-head comparison of dasatinib and nilotinib as second-line treatment outside of sponsored clinical trials has not been reported. We retrospectively analyzed 131 CP-CML patients who, after front-line imatinib failure, switched to a second-line therapy with nilotinib (59, 45%) or dasatinib (72, 55%). Median duration of second-line treatment was 33 months (range 2-100). The reason for switching therapy was resistance in 83.2% and intolerance in 16.8% of patients. The overall survival of the entire cohort at 7 years was 78.9%, while it was 72% and 85.6% for patients treated with dasatinib and nilotinib, respectively (p=0.287). With regard to efficacy after 12 months of treatment, 108 patients were evaluable for molecular response: 47% achieved a major molecular response and 18.2% a deep molecular response with dasatinib, compared to 38% and 16.2% with nilotinib (p=ns). We observed 35% of grade 3-4 adverse events, more frequently in the dasatinib group (47%) compared to the nilotinib group (22%), without affecting molecular responses. Our study suggests that, in the real-life setting, dasatinib and nilotinib used as second-line treatment in CP-CML are equally effective, with high molecular response rates and an acceptable tolerability.

Digital droplet PCR as a predictive tool for successful discontinuation outcome in chronic myeloid leukemia: Is it time to introduce it in the clinical practice?

Tyrosine kinase inhibitors (TKIs) have drastically changed the outcome of chronic myeloid leukemia (CML) patients. A sustained and deep molecular response achieved over time paves the way to therapy discontinuation, and is a pre-requisite to attempt treatment-free remission. Monitoring of the molecular response during treatment discontinuation is routinely carried out by RQ-PCR, but it may not be the optimal tool to monitor minimal residual disease at the time of stopping treatment and during treatment discontinuation. Different digital PCR platforms (such as droplet dPCR) are available, a method based on water-emulsion droplet technology in which the sample is partitioned into 20,000 droplets and PCR amplification of the template subsequently occurs in each individual droplet. The consequent high sensitivity and precision with a very reliable quantification without the need of a calibration curve and the exquisite reproducibility makes this procedure as an ideal alternative method for the detection of very low levels of disease. Aim of this review is to describe and discuss the recent use of dPCR/ddPCR in CML, focusing in particular on its role in TKI treatment discontinuation strategies.

NPM1 Mutated, BCR-ABL1 Positive Myeloid Neoplasms: Review of the Literature.

Breakpoint cluster region - Abelson (BCR-ABL1) chimeric protein and mutated Nucleophosmin (NPM1) are often present in hematological cancers, but they rarely coexist in the same disease. Both anomalies are considered founder mutations that inhibit differentiation and apoptosis, but BCR-ABL1 could act as a secondary mutation conferring a proliferative advantage to a pre-neoplastic clone. The 2016 World Health Organization (WHO) classification lists the provisional acute myeloid leukemia (AML) with BCR-ABL1, which must be diagnosed differentially from the rare blast phase (BP) onset of chronic myeloid leukemia (CML), mainly because of the different therapeutic approach in the use of tyrosine kinase inhibitors (TKI). Here we review the BCR/ABL1 plus NPMc+ published cases since 1975 and describe a case from our institution in order to discuss the clinical and molecular features of this rare combination, and report the latest acquisition about an occurrence that could pertain either to the rare AML BCR-ABL1 positive or the even rarer CML-BP with mutated NPM1 at the onset. Differential diagnosis is based on careful analysis of genotypic and phenotypic features and anamnestic, clinical evolution, and background data. Therapeutic decisions must consider the broader clinical aspects, the comparatively mild effects of TKI therapy versus the great benefit that might bring to most of the patients, as may be incidentally demonstrated by our case history.

Predictive factors for response and survival in elderly acute myeloid leukemia patients treated with hypomethylating agents: a real-life experience.

Predictive factors of response to hypomethylating agents (HMA) in elderly acute myeloid leukemia (AML) patients remain unclear in the real-life setting and no direct comparison between azacitidine (AZA) and decitabine (DEC) has been carried out. We retrospectively evaluated 110 AML patients treated with HMA (78 AZA, 32 DEC) as first-line therapy outside of clinical trials. Median age was 75 years (range 58-87). The median overall survival (OS) of the entire cohort was 8.0 months (95% CI 6.1-10), without significant differences among the subgroups: AZA 8.8 months vs DEC 6.3 months (p = 0.291). HMA treatment yielded an overall response rate (ORR) of 40% (AZA 37% vs DEC 47%, p = 0.237). A stable disease (SD) after 4 HMA cycles was not associated with a worse survival outcome compared with an early optimal response. Factors independently associated with a better OS were transfusion independence during treatment (p = 0.049), achievement of an optimal response to treatment (p < 0.001), and a baseline hemoglobin level ≥ 9.25 (p = 0.018). A bone marrow (BM) blast count ≥ 30% (p < 0.001) and a therapy-related AML (p = 0.008) remain poor survival predictors. Of the available biologic features, an adverse risk category according to the ELN classification was significantly associated with a shorter survival over the intermediate risk category (p = 0.034). Disease progression remains the primary cause of death. Infectious complications were more severe (p = 0.036) and occurred earlier (p = 0.006) in the DEC group compared with that of the AZA group. In conclusion, clinical prognostic factors associated to response and survival have been identified without significant associations concerning overall outcomes between the two HMAs.

Switch from branded to generic imatinib: impact on molecular responses and safety in chronic-phase chronic myeloid leukemia patients.

Since July 2017, different generic imatinib formulations have been introduced in Italy for the treatment of patients with chronic myeloid leukemia (CML). We analyzed 168 chronic phase CML patients treated with branded imatinib for a median of 12 years (range 1-16) at a single institution who switched to a single generic formulation in order to assess the safety and impact on molecular response. The Sokal risk was low/intermediate/high in 63%, 33%, and 4% of patients, respectively. The median duration of generic imatinib treatment was 19 months (range 4-22). Twenty-seven percent of patients were in MMR and 73% were in deep molecular responses (MR4-4.5) at the time of the switch. After 12 months of treatment with generic imatinib, 140 patients were evaluable for response: 23.6% and 76.4% were respectively in MMR and in deep molecular response. When the degree of response was compared with the best molecular response observed with branded imatinib, it was found that 84% of patients maintained the response previously achieved, 6% improved it, and 10% of patients had a molecular fluctuation from the previous deep molecular response to MMR. Only 1 patient lost the MMR and no patient switched to another TKI for inefficacy. In terms of safety, 20% of patients reported new or worsening side effects, but only 2 patients returned to branded imatinib for toxicity. Our data show that the switch to generic imatinib in patients who have been previously treated with branded imatinib appears to maintain efficacy, although a proportion of patients experience new or worsening side effects.

Incidence of Clinically Significant (≤10 g/dL) Late Anemia in Elderly Patients with Newly Diagnosed Chronic Myeloid Leukemia Treated with Imatinib.

BACKGROUND: In elderly patients with chronic myeloid leukemia (CML) responsive to imatinib, the incidence of clinically significant (CS) late chronic anemia is still unknown. MATERIALS AND METHODS: To highlight this issue, we revised retrospectively 81 CML patients aged >60 years treated at our Institution with front-line imatinib for at least 24 months in durable complete cytogenetic response (CCyR). CS late chronic anemia was defined as the presence of persistent (>6 months) and otherwise unexplained Hb levels ≤10 g/dL, which occurred >6 months from imatinib start. RESULTS: A condition of CS late chronic anemia occurred in 22 out of 81 patients (27.2%) at different intervals from imatinib start. Seven out of 22 patients (31.8%) needed packed red cell transfusions during the follow-up. At diagnosis, patients who developed CS late chronic anemia were significantly older and had a lower Hb median level. Six out of 22 patients with CS late chronic anemia received subcutaneous recombinant alpha-erythropoietin (EPO) at the standard dosage of 40,000 IU weekly: all 6 patients achieved an erythroid response. A significantly worse event-free survival (EFS) in patients with untreated CS late chronic anemia was observed (p = 0.012). CONCLUSIONS: CS late chronic anemia during long-term treatment with imatinib is a common complication in responsive elderly patients, with worse EFS if untreated. Results with EPO are encouraging, but larger studies are warranted to define its role.

Ten-year outcome of chronic-phase chronic myeloid leukemia patients treated with imatinib in real life.

Imatinib, the first BCR/ABL kinase inhibitor approved for the treatment of chronic myeloid leukemia (CML), has changed the long-term outcome of patients affected by this disease. The aim of our analysis was to report, after a median follow-up of 10.2 years (range 5.8-14.8), the long-term outcome, efficacy, and safety of imatinib treatment (frontline and after interferon failure) in a single institution cohort of 459 patients with CML in chronic phase treated outside of clinical trials. The 10-year overall survival of the whole cohort was 77.1%, while the 10-year probability of dying due to CML and other causes was 7.8% and 16%, respectively. The prognostic value of the BCR-ABL1 ratio at 3 months (⩽ 10%) and of complete cytogenetic response and major molecular response at 1 year was confirmed also in the real-life practice. The EUTOS long-term survival score better stratified the baseline risk of dying of CML compared with other risk scores. Two hundred thirty-six (51.4%) patients achieved a deep molecular response during imatinib treatment after a median time of 4.57 years, and 95 (20.6%) had a stable deep molecular response maintained for at least 2 consecutive years. Imatinib was associated with a low rate of serious cardiovascular events and second neoplasia. This 10-year real-life follow-up study shows that imatinib maintains efficacy over time and that long-term administration of imatinib is not associated with notable cumulative or late toxic effects.

Prolonged treatment with arsenic trioxide (ATO) and all-trans-retinoic acid (ATRA) for relapsed acute promyelocytic leukemia previously treated with ATRA and chemotherapy.

Prolonged therapy with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) is highly effective in newly diagnosed acute promyelocytic leukemia (APL) but there is limited data on the efficacy of this regimen in the relapse setting. We report here on 22 APL patients treated with prolonged ATRA-ATO therapy at the time of disease relapse. Twenty patients obtained molecular complete remission (CRm) after 2 cycles (90%). Of these, two patients underwent hematopoietic stem cell transplant (HSCT) while the remaining proceeded to receive additional cycles (up to a total of 5) of ATRA-ATO. With a median follow-up of 58 months from the time of relapse (range: 21-128 months), the 4-year OS probability was 0.85 (95% CI 0.61-0.94), DFS was 0.74 (95% CI 0.49-0.88), and EFS 0.68 (95% CI 0.45-0.83). Two patients were resistant to ATRA-ATO salvage and five relapsed at a median of 19 months. Of these, four died due to progressive disease while three relapsed achieved a new CRm after further salvage therapy. This experience confirms the potentially curative effect of prolonged ATRA-ATO therapy in relapsed APL, especially in patients with long first complete remission.