Outcomes with single-agent gilteritinib for relapsed or refractory FLT3-mutant AML after contemporary induction therapy.

Gilteritinib is the current standard of care for relapsed or refractory FLT3-mutated AML in many countries, however outcomes for patients relapsing after contemporary first-line therapies (intensive chemotherapy with midostaurin, or non-intensive chemotherapy with venetoclax) are uncertain. Moreover, reported data on toxicity and healthcare resource use is limited. Here we describe a large real-world cohort of 152 patients receiving single-agent gilteritinib in 38 UK hospitals. Median age was 61 and 36% had received 2 prior lines of therapy, including a FLT3 inhibitor in 41% and venetoclax in 24%. A median of 4 cycles of gilteritinib were administered, with 56% of patients requiring hospitalisation in the first cycle (median 10 days). Over half of patients required transfusion in each of the first 4 cycles. Complete remission (CR) was achieved in 21% and CR with incomplete recovery in a further 9%. Remission rates were lower for patients with FLT3-TKD or adverse karyotype. Day 30 and day 60 mortality were 1% and 10.6% and median overall survival was 9.5 months. On multivariable analysis, increasing age, KMT2A rearrangement and complex karyotype were associated with worse survival while RUNX1 mutations were associated with improved survival. Twenty patients received gilteritinib as first salvage having progressed following first-line therapy with venetoclax, with CR/CRi achieved in 25% and median survival 4.5 months. Real-world results with gilteritinib mirror those seen in the clinical trials but outcomes remain suboptimal, with more effective strategies needed.

Treatment outcomes in patients with large B-cell lymphoma after progression to chimeric antigen receptor T-cell therapy.

Over 60% of relapsed/refractory (R/R) large B-cell lymphoma (LBCL) patients who receive chimeric antigen receptor (CAR) T cells will experience disease progression. There is no standard next line of therapy and information in this setting is scarce and heterogeneous. We analyzed 387 R/R LBCL patients who progressed after CAR T cells from July 2018 until March 2022 in Spain and the United Kingdom. Median overall survival (OS) was 5.3 months, with significant differences according to the interval between infusion and progression (<2 months [1.9 months], 2-6 months [5.2 months], and >6 months [not reached]). After progression, 237 (61%) patients received treatment. Focusing on the first subsequent therapy, overall (complete) response rates were 67% (38%) for polatuzumab-bendamustine-rituximab (POLA), 51% (36%) for bispecific antibodies (BsAb), 45% (35%) for radiotherapy (RT), 33% (26%) for immune checkpoint inhibitors (ICIs), 25% (0%) for lenalidomide (LENA), and 25% (14%) for chemotherapy (CT). In terms of survival, 12-month progression-free survival and OS was 36.2% and 51.0% for POLA, 32.0% and 50.1% for BsAb, 30.8% and 37.5% for RT, 29.9% and 27.8% for ICI, 7.3% and 20.8% for LENA, and 6.1% and 18.3% for CT. Thirty-two (14%) patients received an allogeneic hematopoietic cell transplant with median OS not reached after a median follow-up of 15.1 months. In conclusion, patients with R/R LBCL who progress within the first 2 months after CAR T-cell therapy have dismal outcomes. Novel targeted agents, such as polatuzumab and BsAbs, can achieve prolonged survival after CAR T-cell therapy failure.

Molecular MRD is strongly prognostic in patients with NPM1-mutated AML receiving venetoclax-based nonintensive therapy.

ABSTRACT: Assessment of measurable residual disease (MRD) by quantitative reverse transcription polymerase chain reaction is strongly prognostic in patients with NPM1-mutated acute myeloid leukemia (AML) treated with intensive chemotherapy; however, there are no data regarding its utility in venetoclax-based nonintensive therapy, despite high efficacy in this genotype. We analyzed the prognostic impact of NPM1 MRD in an international real-world cohort of 76 previously untreated patients with NPM1-mutated AML who achieved complete remission (CR)/CR with incomplete hematological recovery following treatment with venetoclax and hypomethylating agents (HMAs) or low-dose cytarabine (LDAC). A total of 44 patients (58%) achieved bone marrow (BM) MRD negativity, and a further 14 (18%) achieved a reduction of ≥4 log10 from baseline as their best response, with no difference between HMAs and LDAC. The cumulative rates of BM MRD negativity by the end of cycles 2, 4, and 6 were 25%, 47%, and 50%, respectively. Patients achieving BM MRD negativity by the end of cycle 4 had 2-year overall of 84% compared with 46% if MRD was positive. On multivariable analyses, MRD negativity was the strongest prognostic factor. A total of 22 patients electively stopped therapy in BM MRD-negative remission after a median of 8 cycles, with 2-year treatment-free remission of 88%. In patients with NPM1-mutated AML attaining remission with venetoclax combination therapies, NPM1 MRD provides valuable prognostic information.

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.

A national service for delivering CD19 CAR-Tin large B-cell lymphoma - The UK real-world experience.

CD19 CAR-T have emerged as a new standard treatment for relapsed/refractory (r/r) large B-cell lymphoma (LBCL). CAR-T real-world (RW) outcomes published to date suggest significant variability across countries. We provide results of a large national cohort of patients intended to be treated with CAR-T in the UK. Consecutive patients with r/r LBCL approved for CAR-T by the National CAR-T Clinical Panel between December 2018 and November 2020 across all UK CAR-T centres were included. 404/432 patients were approved [292 axicabtagene ciloleucel (axi-cel), 112 tisagenlecleucel (tisa-cel)], 300 (74%) received the cells. 110/300 (38.3%) patients achieved complete remission (CR) at 6 months (m). The overall response rate was 77% (52% CR) for axi-cel, 57% (44% CR) for tisa-cel. The 12-month progression-free survival was 41.8% (axi-cel) and 27.4% (tisa-cel). Median overall survival for the intention-to-treat population was 10.5 m, 16.2 m for infused patients. The incidence of grade ≥3 cytokine release syndrome and neurotoxicity were 7.6%/19.6% for axi-cel and 7.9%/3.9% for tisa-cel. This prospective RW population of CAR-T eligible patients offers important insights into the clinical benefit of CD19 CAR-T in LBCL in daily practice. Our results confirm long-term efficacy in patients receiving treatment similar to the pivotal trials, but highlight the significance of early CAR-T failure.

BRD4-mediated repression of p53 is a target for combination therapy in AML.

Acute myeloid leukemia (AML) is a typically lethal molecularly heterogeneous disease, with few broad-spectrum therapeutic targets. Unusually, most AML retain wild-type TP53, encoding the pro-apoptotic tumor suppressor p53. MDM2 inhibitors (MDM2i), which activate wild-type p53, and BET inhibitors (BETi), targeting the BET-family co-activator BRD4, both show encouraging pre-clinical activity, but limited clinical activity as single agents. Here, we report enhanced toxicity of combined MDM2i and BETi towards AML cell lines, primary human blasts and mouse models, resulting from BETi's ability to evict an unexpected repressive form of BRD4 from p53 target genes, and hence potentiate MDM2i-induced p53 activation. These results indicate that wild-type TP53 and a transcriptional repressor function of BRD4 together represent a potential broad-spectrum synthetic therapeutic vulnerability for AML.

Lifting the Differentiation Embargo.

Effective differentiation therapy for acute myeloid leukemia (AML) has been restricted to a small subset of patients with one defined genetic abnormality. Using an unbiased small molecule screen, Sykes et al. now identify a mechanism of de-repression of differentiation in several models of AML driven by distinct genetic drivers.

Allogeneic stem cell transplantation for chronic myeloid leukaemia is safe and effective in high risk patients following second generation tyrosine kinase inhibitors: A single centre's experience.

Most patients now receiving a haematopoietic stem cell transplant (HSCT) for chronic myeloid leukaemia (CML) have been treated with first and second line TKIs pre-HSCT, raising concerns that these patients will have more resistant disease and accumulated greater toxicity from sequential lines of therapy, potentially compromising their outcome. We outline a series of 9 patients treated with imatinib then second generation TKIs for CML followed by HSCT and compare their outcomes with patients receiving imatinib-only pre-HSCT. Our case series demonstrates that second line and sequential tyrosine kinase inhibitors followed by HSCT is a safe and effective therapeutic approach for high risk CML.

Splenectomy as an effective debulking therapy for disseminated mould infection in acute myeloid leukaemia following adjuvant therapy with interferon gamma and liposomal amphotericin.

Invasive fungal infection is a major cause of morbidity and mortality in patients receiving treatment for Acute Myeloid Leukaemia (AML). Herein, we report a case of a 21 year old woman with an extremely resistant Fusarium species that responded to the addition of interferon gamma to her medical therapy, subsequently allowing definitive debulking surgery of her invasive Fusarium infection to be undertaken.