The outcome of patients with relapsed or refractory (R/R) acute lymphoblastic leukemia (ALL) is poor. Inotuzumab ozogamicin, a CD22 monoclonal antibody bound to calicheamicin, has single-agent ...activity in R/R ALL.
To evaluate the efficacy and safety of inotuzumab ozogamicin plus low-intensity chemotherapy in patients with R/R ALL.
A single-arm, phase 2 study of adults with R/R B-cell ALL conducted at The University of Texas MD Anderson Cancer Center, Houston.
The chemotherapy used was lower intensity than hyper-CVAD (cyclophosphamide, vincristine, doxorubicin trade name, Adriamycin; Pfizer, and dexamethasone) and is referred to as mini-hyper-CVD (mini-HCVD: cyclophosphamide and dexamethasone at 50% dose reduction, no anthracycline, methotrexate at 75% dose reduction, and cytarabine at 0.5 g/m2 × 4 doses). Inotuzumab was given on day 3 of the first 4 courses at 1.8 to 1.3 mg/m2 for cycle 1 followed by 1.3 to 1.0 mg/m2 for subsequent cycles.
The primary end points were the overall response rate and overall survival (OS). Secondary end points included safety, relapse-free survival (RFS), the rate of allogeneic stem cell transplantation (ASCT), and the minimal residual disease (MRD) negativity rate.
Fifty-nine patients (30 women and 29 men) with a median age of 35 years (range, 18-87 years) were treated. Overall, 46 patients (78%) responded, 35 of them (59%) achieving complete response. The overall MRD negativity rate among responders was 82%. Twenty-six patients (44%) received ASCT. Grade 3 to 4 toxic effects included prolonged thrombocytopenia (81%; n = 48), infections (73%; n = 43), and hyperbilirubinemia (14%; n = 8). Veno-occlusive disease (VOD) occurred in 9 patients (15%). With a median follow-up of 24 months, the median RFS and OS were 8 and 11 months, respectively. The 1-year RFS and OS rates were 40% and 46%, respectively. The 1-year OS rates for patients treated in salvage 1, salvage 2, and salvage 3 or beyond were 57%, 26%, and 39%, respectively (P = .03).
The combination of inotuzumab with low-intensity mini-HCVD chemotherapy shows encouraging results in R/R ALL. The risk of VOD should be considered carefully in patients with previous liver damage and among transplant candidates.
clinicaltrials.gov Identifier: NCT01371630.
6519 Background: We report the outcomes of a phase 2 study of FLAG-IDA+VEN in AML. Methods: Pts ≥18 with ND or RR AML / MDS-EB2 fit for intensive chemotherapy were eligible. Induction comprised ...fludarabine 30mg/m 2 D2–6, cytarabine 1.5g/m 2 D2–6, idarubicin 8 (6 if RR) mg/m 2 D4–6 & filgrastim 5mcg/kg D1–7. VEN 400mg was administered D1–14 with CYP3A inhibitor dose adjustment until Jul 2023; following a protocol modification, VEN is now administered D1–7. The primary outcome was ORR (CR + CRh + CRi + MLFS + PR). Secondary outcomes were CRc (CR + CRh + CRi), overall survival (OS), event-free survival (EFS) & duration of response (DOR). Measurable residual disease (MRD) was assessed by flow cytometry. Results: As of Jan 2024, 134 pts have enrolled, 127 (68 ND & 59 RR) evaluable at data cut. Median age was 45 (18 – 73); 19 (15%) age ≥60. 13 (19%), 22 (32%) & 33 (49%) ND pts were ELN22 favorable, intermediate & adverse respectively. There were 7 (10%) secondary (s), including 4 hypomethylating agent failure, & 7 (10%) therapy-related (t) AML. In RR pts, 40 (68%) were in salvage 1 (S1), of whom 32 (54%) were TP53 WT . 20 (34%) had prior stem cell transplant (SCT). Median of 2 cycles were given. In ND pts, ORR was 99%, (96% CRc, of whom 89% MRD negative Table). Similar responses were seen across ELN groups & s/tAML. At median follow-up (mFU) of 30 months (mo), the mOS, mEFS & mDOR were not reached. The 2yr OS, EFS & DOR were 75% (64 – 88), 68% (56 – 81) & 71% (59 – 85) respectively, with no differences among ELN groups. 57% went to SCT in CR1. 4/4 pts with TP53 mut became CRc MRD–, but mDOR was only 8.2 mo (95% CI, 2.2 – NE), resulting in poor mOS (13.5 mo, 95% CI, 8.6 – NE). In RR pts, ORR was 70% (66% CRc, of whom 79% MRD negative Table). At mFU 27 mo, the mOS, mEFS & mDOR were 12 (7 – 33), 7 (4 – 23) & 21 (8 – NE) mo respectively. The 2yr OS, EFS & DOR were 40% (28 – 55), 34% (23 – 49) & 49% (35 – 68) respectively. 58% went to SCT. S1+ TP53 WT pts had mOS of 34 mo (12 – NE), with 72% going to SCT. 30d & 60d mortality were 0% & 3%. Of the 4 deaths within 60d, 1 was sepsis-related in CR in a ND pt while 3 were disease-related in NR RR pts. The most frequent adverse event was infection. Grade ≥3 infections, gastrointestinal toxicities & bleeding occurred in 102 (80%), 20 (16%) & 9 (7%) pts respectively. The median time to neutrophil >1x10 9 /L & platelet >50x10 9 /L were 27d & 28d for C1, 39d & 67d for C2 & 35d & 50d for C3 respectively. Conclusions: FLAG-IDA+VEN results in high MRD negative response rates, leading to impressive survival outcomes across ELN risk groups in ND AML. It is an effective salvage regimen for RR AML, especially for S1+ TP53 WT pts. Clinical trial information: NCT03214562 . Table: see text
6549 Background: We report long-term results of phase 2 study of 10-day DEC and VEN (DEC10-VEN) in AML/HR-MDS. Methods: This single-institution study (NCT03404193) included intensive ...chemotherapy-ineligible pts >60y with ND de novo AML or secondary AML (sAML), or R/R AML, or HR-MDS. Induction therapy: DAC 20 mg/m 2 IV x 10d + VEN days 1-28. VEN was stopped on day 21 if bone marrow blasts ≤5%. Consolidation included DEC IV x 5 days + VEN days 1-21, every 4-8 weeks as previously described (DiNardo et al. Lancet Haem. 2020). Primary endpoint was ORR. Secondary endpoints are duration of response, OS, RFS, and safety. Here, we report an update with 232 pts and results of HR-MDS/CMML cohort. Results: 232 pts were enrolled thus far (ND AML-86; sAML-49; R/R AML-76; HR-MDS/CMML-21). Median follow up is 39 mo (36-46 mo). Median age was 73y in ND AML and 64y in R/R AML (Table). Three-fourths of pts inAML cohort were adverse risk by ELN 2022 risk. CR/CRi rates in ND AML, sAML, and R/R AML were 92%, 53%, and 40% and ORR was 88%, 69%, 58%, respectively. Median OS was 12.3 mo in frontline (FL, ND (16.7 mo) and sAML (10.4 mo)) and 7.6 mo in R/R. Similarly, median RFS was 9.1 (ND-10 mo and sAML-6.4 mo) and 7.5 mo, respectively. Median time to ANC ≥500 x 10 9 /L in cycle 1 was 41 days and Plt ≥50 x 10 9 /L was 31 days in FL pts. 30-day mortality was 2% in FL and 5% in R/R cohort. 18% in FL and 22% in R/R cohort proceeded to SCT. In HR-MDS cohort, the median age was 71y; 18/21 pts had prior treatment. ASXL1 was the most frequent mutation. ORR was 52% (CR+CRi-33%). Median OS-12.1, RFS-7.3 mo. Median time to ANC ≥500 x 10 9 /L was 55 and plt ≥50 x 10 9 /L was 51 days. Most common grade 3/4 AEs were infection with neutropenia (38%), febrile neutropenia (32%), thrombocytopenia (17%), and neutropenia (15%), consistent with HMA + VEN experience. Conclusions: DEC10-VEN demonstrated expected safety and efficacy in a particularly high-risk cohort of ND and R/R pts, with no evidence that 10-days of DEC provides improved responses over standard 5-days DEC. Clinical trial information: NCT03404193 . Table: see text
Fms-like tyrosine kinase-3 (FLT3) inhibitors have been used to overcome the dismal prognosis of acute myeloid leukemia (AML) with FLT3 mutations. Clinical results with FLT3 inhibitor monotherapy have ...shown that bone marrow responses are commonly less pronounced than peripheral blood responses. We investigated the role of p53 in bone marrow stromal cells in stromal cell-mediated resistance to FLT3 inhibition in FLT3 mutant AML. While the FLT3 inhibitor FI-700 induced apoptosis in FLT3 mutant AML cells, apoptosis induction was diminished under stromal coculture conditions. Protection appeared to be mediated, in part, by CXCL12 (SDF-1)/CXCR4 signaling. The protective effect of stromal cells was significantly reduced by pre-exposure to the HDM2 inhibitor Nutlin-3a. p53 activation by Nutlin-3a was not cytotoxic to stromal cells, but reduced CXCL12 mRNA levels and secretion of CXCL12 partially through p53-mediated HIF-1α down-regulation. Results show that p53 activation in stroma cells blunts stroma cell-mediated resistance to FLT3 inhibition, in part through down-regulation of CXCL12. This is the first report of Nutlin effect on the bone marrow environment. We suggest that combinations of HDM2 antagonists and FLT3 inhibitors may be effective in clinical trials targeting mutant FLT3 leukemias.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Aberrant expression of Aurora kinases and inactivation of wild-type p53 by Mdm2 overexpression are frequent molecular events in acute myelogenous leukemia (AML), and preclinical data for inhibition ...of Aurora kinases or Mdm2 are promising. However, it remains largely unknown whether the viability of cells exposed to Aurora kinase inhibitors depends on the p53 status. We investigated the interaction of Aurora kinases and p53 pathways after their simultaneous blockades using a small-molecule pan-Aurora kinase inhibitor, MK-0457, and a selective small-molecule antagonist of Mdm2, Nutlin-3. We found that MK-0457, which itself activates p53 signaling, acts synergistically with Nutlin-3 to induce apoptosis in wild-type p53 AML cell lines OCI-AML-3 and MOLM-13 but not in p53-null HL-60 cells. MK-0457 and Nutlin-3 showed synergism in inducing p53, conformational change of Bax and Δψm loss, suggesting an involvement of p53-mediated mitochondrial apoptosis. Nutlin-3 constrained endoreduplication after Aurora inhibition via activation of a p53-dependent postmitotic checkpoint and p21 induction in pseudo-G1 cells. Our findings provide the molecular rationale for concomitant targeting of Aurora kinases and Mdm2 in AML where TP53 mutations are rare and downstream p53 signaling is mostly intact.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Blinatumomab, a bi‐specific T‐cell engaging CD3‐CD19 antibody construct, has shown significant activity in patients with relapsed/refractory (R/R) B‐cell acute lymphoblastic leukemia (ALL). Despite ...this improvement, most patients relapse. Here, we describe the outcome of 68 patients with R/R ALL after failure of blinatumomab therapy: 38 (56%) blinatumomab refractory; 30 (44%) relapsing after initial response. After a median follow‐up of 49 months, 9 (13%) patients remained alive. The median overall survival after blinatumomab failure was 5.2 months. At the time of failure, among 61 patients evaluated for immunophenotype, 56 (92%) had CD19‐positive blasts; only five (8%) had ALL recurrence with CD19‐negative disease. Two patients progressed with lower CD19 expression. In summary, the outcome of patients with R/R ALL after blinatumomab failure is poor and treatment of these patients remains an unmet medical need. Our findings indicate that blinatumomab therapy would not exclude a significant number of patients from the potential benefit of subsequent CD19‐directed therapies such as chimeric antigen receptor T‐cell therapy.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Summary
Clonal haematopoiesis (CH) in patients with acute myeloid leukaemia (AML) may persist beyond attaining complete remission. From a consecutive cohort of 67 patients with nucleophosmin ...1‐mutated (NPM1mut) AML, we identified 50 who achieved NPM1mut clearance and had parallel multicolour flow cytometry (MFC) and next generation sequencing (NGS). In total, 13 (26%) cleared all mutations, 37 (74%) had persistent CH frequently involving DNA methyltransferase 3α (DNMT3A,70%), tet methylcytosine dioxygenase 2 (TET2, 27%), isocitrate dehydrogenase 2 (IDH2, 19%) and IDH1 (11%). A small number (<1%) of aberrant CD34+ myeloblasts, but immunophenotypically different from original AML blasts herein referred to as a pre‐leukaemic (PL) phenotype, was detected in 17 (49%) patients with CH, but not in any patients with complete clearance of all mutations (P = 0·0037). A PL phenotype was associated with higher mutation burden (P = 0·005). Persistent IDH2 and serine and arginine‐rich splicing factor 2 (SRSF2) mutations were exclusively observed in PL+ CH+ cases (P = 0·016). Persistent dysplasia was seen exclusively in cases with a PL+ phenotype (29% vs. none; P = 0·04). The PL+ phenotype did not correlate with age, intensity of induction therapy or relapse‐free survival. Post‐remission CH in the setting of NPM1mut clearance is common and may result in immunophenotypic changes in myeloid progenitors. It is important to not misinterpret these cells as AML measurable residual disease (MRD).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
BCL-2 inhibition has transformed the therapeutic landscape of acute myeloid leukemia (AML) but is not curative for the majority of patients. Consequently, there has been growing interest in targeting ...other facets of the apoptotic machinery to improve outcomes. These approaches include targeting the intrinsic and extrinsic apoptotic pathway, inducing apoptosis via p53 activation, and others. Targeting the intrinsic apoptotic pathway includes MCL-1 antagonism and BCL-xL inhibition. MCL-1 can be targeted via direct inhibitors as well as via indirect mechanisms to downregulate MCL-1 including inhibition of cyclin dependent kinases and Nedd8 activating enzyme. The extrinsic apoptotic pathway could be harnessed via inhibition of inhibitor of apoptosis proteins, agonism of the TNF-related apoptosis-inducing ligand receptors and inhibiting FLICE-like inhibitor protein. Approaches inducing p53-mediated apoptosis are being evaluated using inhibitors of MDM2, dual inhibitor of MDM2/X in TP53 wild-type AML and p53 reactivators in TP53-mutant myeloid disorders. Several such agents are in early clinical development and rationale combinations of these agents may help improving outcomes for patients with AML.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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