Venetoclax-based low intensity therapy in molecular failure of NPM1-mutated AML.

ABSTRACT: Molecular failure in NPM1-mutated acute myeloid leukemia (AML) inevitably progresses to frank relapse if untreated. Recently published small case series show that venetoclax combined with low-dose cytarabine or azacitidine can reduce or eliminate measurable residual disease (MRD). Here, we report on an international multicenter cohort of 79 patients treated for molecular failure with venetoclax combinations and report an overall molecular response (≥1-log reduction in MRD) in 66 patients (84%) and MRD negativity in 56 (71%). Eighteen of 79 patients (23%) required hospitalization, and no deaths were reported during treatment. Forty-one patients were bridged to allogeneic transplant with no further therapy, and 25 of 41 were MRD negative assessed by reverse transcription quantitative polymerase chain reaction before transplant. Overall survival (OS) for the whole cohort at 2 years was 67%, event-free survival (EFS) was 45%, and in responding patients, there was no difference in survival in those who received a transplant using time-dependent analysis. Presence of FLT3-ITD mutation was associated with a lower response rate (64 vs 91%; P < .01), worse OS (hazard ratio [HR], 2.50; 95% confidence interval [CI], 1.06-5.86; P = .036), and EFS (HR, 1.87; 95% CI, 1.06-3.28; P = .03). Eighteen of 35 patients who did not undergo transplant became MRD negative and stopped treatment after a median of 10 months, with 2-year molecular relapse free survival of 62% from the end of treatment. Venetoclax-based low intensive chemotherapy is a potentially effective treatment for molecular relapse in NPM1-mutated AML, either as a bridge to transplant or as definitive therapy.

FLT3 inhibitors as MRD-guided salvage treatment for molecular failure in FLT3 mutated AML.

Patients with FLT3-mutated AML have a high relapse rate and suboptimal outcomes. Many have co-mutations suitable for measurable residual disease (MRD) monitoring by RT-qPCR and those destined to relapse can be identified by high or rising levels of MRD, called molecular failure.  This provides a window for pre-emptive intervention, but there is little evidence to guide treatment. The use of FLT3 inhibitors (FLT3i) appears attractive but their use has not yet been evaluated.  We identified 56 patients treated with FLT3i at molecular failure.  The FLT3 mutation was an ITD in 52, TKD in 7 and both in 3. Over half of patients had previously received midostaurin. Molecular failure occurred at a median 9.2 months from diagnosis and was treated with gilteritinib (n = 38), quizartinib (n = 7) or sorafenib (n = 11). 60% achieved a molecular response, with 45% reaching MRD negativity. Haematological toxicity was low, and 22 patients were bridged directly to allogeneic transplant with another 6 to donor lymphocyte infusion. 2-year overall survival was 80% (95%CI 69-93) and molecular event-free survival 56% (95%CI 44-72). High-sensitivity next-generation sequencing for FLT3-ITD at molecular failure identified patients more likely to benefit. FLT3i monotherapy for molecular failure is a promising strategy which merits evaluation in prospective studies.

Infections in relapsed myeloma patients treated with isatuximab plus pomalidomide and dexamethasone during the COVID-19 pandemic: Initial results of a UK-wide real-world study.

OBJECTIVES: There are no real-world data describing infection morbidity in relapsed/refractory myeloma (RRMM) patients treated with anti-CD38 isatuximab in combination with pomalidomide and dexamethasone (IsaPomDex). In this UK-wide retrospective study, we set out to evaluate infections experienced by routine care patients who received this novel therapy across 24 cancer centres during the COVID-19 pandemic. METHODS: The primary endpoint was infection morbidity (incidence, grading, hospitalization) as well as infection-related deaths. Secondary outcomes were clinical predictors of increased incidence of any grade (G2-5) and high grade (≥G3) infections. RESULTS: In a total cohort of 107 patients who received a median (IQR) of 4 cycles (2-8), 23.4% of patients experienced ≥1 any grade (G2-5) infections (total of 31 episodes) and 18.7% of patients experienced ≥1 high grade (≥G3) infections (total of 22 episodes). Median time (IQR) from start of therapy to first episode was 29 days (16-75). Six patients experienced COVID-19 infection, of whom 5 were not vaccinated and 1 was fully vaccinated. The cumulative duration of infection-related hospitalizations was 159 days. The multivariate (MVA) Poisson Regression analysis demonstrated that a higher co-morbidity burden with Charlson Co-morbidity Index (CCI) score ≥4 (incidence rate ratio (IRR) = 3, p = 0.012) and sub-optimal myeloma response less than a partial response (

Efficacy of Isatuximab With Pomalidomide and Dexamethasone in Relapsed Myeloma: Results of a UK-Wide Real-World Dataset.

Real-world data on the efficacy and tolerability of isatuximab with pomalidomide and dexamethasone (IsaPomDex) in relapsed/refractory myeloma patients have not been reported. In this UK-wide retrospective study, IsaPomDex outcomes were evaluated across 24 routine care cancer centers. The primary endpoint was overall response rate (ORR). Secondary endpoints included progression-free survival (PFS), duration of response (DOR) for patients who achieved an objective response (≥partial response [PR]), and adverse events (AEs). In a total cohort 107 patients, median follow up (interquartile range [IQR]) was 12.1 months (10.1-18.6 mo), median age (IQR) was 69 years (61-77). Median (IQR) Charlson Comorbidity Index (CCI) score was 3 (2-4); 43% had eGFR <60 mL/min. Median (IQR) number of prior therapies was 3 (3-3). Median (IQR) number of IsaPomDex cycles administered was 7 (3-13). ORR was 66.4%, with responses categorized as ≥ very good partial response: 31.8%, PR: 34.6%, stable disease: 15.9%, progressive disease: 15%, and unknown 2.8%. Median PFS was 10.9 months. Median DOR was 10.3 months. There was no statistical difference in median PFS by age (<65: 10.2 versus 65-74 13.2 versus ≥75: 8.5 mo, log-rank P = 0.4157), by CCI score (<4: 10.2 mo versus ≥4: 13.2, log-rank P = 0.6531), but inferior PFS was observed with renal impairment (≥60: 13.2 versus <60: 7.9 mo, log-rank P = 0.0408). Median OS was 18.8 months. After a median of 4 cycles, any grade AEs were experienced by 87.9% of patients. The most common ≥G3 AEs were neutropenia (45.8%), infections (18.7%), and thrombocytopenia (14%). Our UK-wide IsaPomDex study demonstrated encouraging efficacy outcomes in the real world, comparable to ICARIA-MM trial.

Outcomes of older patients with primary central nervous system lymphoma treated in routine clinical practice in the UK: methotrexate dose intensity correlates with response and survival.

Data on older patients with primary central nervous system lymphoma (PCNSL) are scarce. Comorbidities and performance status frequently compromise outcomes in this group. Medical records for consecutive patients ≥65 years (n = 244) with PCNSL diagnosed 2012-2017 from 14 UK centres were retrospectively reviewed. Of these 192 patients received methotrexate (MTX)-based treatment. Patients were categorised based on clinician's treatment choice into 'palliative' (n = 52), 'less intensive: MTX ± rituximab ± alkylators' (n = 74) and 'intensive: MTX/cytarabine combinations' (n = 118) groups. Complete remission (CR) rate, two-year progression-free survival (PFS) and overall survival (OS) rates were 49%, 11% and 24% for the less intensive and 69%, 40% and 50% for the intensive groups. Treatment-related mortality (TRM) was 6·8% for MTX-treated patients. Median MTX cumulative dose was 8·8 g/m2 (range 1·5-21) over a median of three cycles. Higher relative dose intensity of MTX (MTX-RDI) was associated with improved PFS and OS in both groups adjusting for age, Eastern cooperative oncology group (ECOG) score and baseline parameters. Two-year PFS and OS for patients receiving four or more induction cycles followed by consolidation (n = 36) were 65% and 70% respectively. Older patients completing MTX-based induction and consolidation had clinical outcomes similar to those in younger cohorts. These retrospective data suggest that maximising MTX-RDI and delivering consolidation in a subgroup of older patients may improve clinical outcomes.

ACTN1-related thrombocytopenia: identification of novel families for phenotypic characterization.

Inherited thrombocytopenias (ITs) are a heterogeneous group of syndromic and nonsyndromic diseases caused by mutations affecting different genes. Alterations of ACTN1, the gene encoding for α-actinin 1, have recently been identified in a few families as being responsible for a mild form of IT (ACTN1-related thrombocytopenia; ACTN1-RT). To better characterize this disease, we screened ACTN1 in 128 probands and found 10 (8 novel) missense heterozygous variants in 11 families. Combining bioinformatics, segregation, and functional studies, we demonstrated that all but 1 amino acid substitution had deleterious effects. The clinical and laboratory findings of 31 affected individuals confirmed that ACTN1-RT is a mild macrothrombocytopenia with low risk for bleeding. Low reticulated platelet counts and only slightly increased serum thrombopoietin levels indicated that the latest phases of megakaryopoiesis were affected. Given its relatively high frequency in our cohort (4.2%), ACTN1-RT has to be taken into consideration in the differential diagnosis of ITs.