Treatment of newly diagnosed diffuse large B‐cell lymphoma with rituximab and CHOP (R‐CHOP) has been largely unchanged for the last two decades. The Guideline by Fox et al. provides new ...evidence‐based therapeutic strategies informed by positive results of randomised clinical trials.
Commentary on: Fox et al. The management of newly diagnosed large B‐cell lymphoma: A British Society for Haematology Guideline. Br J Haematol 2024; 204:1178‐1192.
The treatment landscape of B-cell lymphomas is evolving with the advent of novel agents including immune and cellular therapies. Bispecific antibodies (bsAbs) are molecules that recognise two ...different antigens and are used to engage effector cells, such as T-cells, to kill malignant B-cells. Several bispecific antibodies have entered early phase clinical development since the approval of the CD19/CD3 bispecific antibody, blinatumomab, for relapsed/refractory acute lymphoblastic leukaemia. Novel bsAbs include CD20/CD3 antibodies that are being investigated in both aggressive and indolent non-Hodgkin lymphoma with encouraging overall response rates including complete remissions. These results are seen even in heavily pre-treated patient populations such as those who have relapsed after chimeric antigen receptor T-cell therapy. Potential toxicities include cytokine release syndrome, neurotoxicity and tumour flare, with a number of strategies existing to mitigate these risks. Here, we review the development of bsAbs, their mechanism of action and the different types of bsAbs and how they differ in structure. We will present the currently available data from clinical trials regarding response rates, progression free survival and outcomes across a range of non-Hodgkin lymphoma subtypes. Finally, we will discuss the key toxicities of bsAbs, their rates and management of these adverse events.
Translocations of the mixed lineage leukemia (MLL) gene occur in 60% to 80% of all infant acute leukemias and are markers of poor prognosis. MLL-AF9 and other MLL fusion proteins aberrantly recruit ...epigenetic regulatory proteins, including histone deacetylases (HDAC), histone methyltransferases, bromodomain-containing proteins, and transcription elongation factors to mediate chromatin remodeling and regulate tumorigenic gene expression programs. We conducted a small-molecule inhibitor screen to test the ability of candidate pharmacologic agents targeting epigenetic and transcriptional regulatory proteins to induce apoptosis in leukemic cells derived from genetically engineered mouse models of MLL-AF9-driven acute myeloid leukemia (AML). We found that the CDK inhibitor dinaciclib and HDAC inhibitor panobinostat were the most potent inducers of apoptosis in short-term in vitro assays. Treatment of MLL-rearranged leukemic cells with dinaciclib resulted in rapidly decreased expression of the prosurvival protein Mcl-1, and accordingly, overexpression of Mcl-1 protected AML cells from dinaciclib-induced apoptosis. Administration of dinaciclib to mice bearing MLL-AF9-driven human and mouse leukemias elicited potent antitumor responses and significantly prolonged survival. Collectively, these studies highlight a new therapeutic approach to potentially overcome the resistance of MLL-rearranged AML to conventional chemotherapies and prompt further clinical evaluation of CDK inhibitors in AML patients harboring MLL fusion proteins.
MCL-1 is one of the most frequently amplified genes in cancer, facilitating tumor initiation and maintenance and enabling resistance to anti-tumorigenic agents including the BCL-2 selective inhibitor ...venetoclax. The expression of MCL-1 is maintained via P-TEFb-mediated transcription, where the kinase CDK9 is a critical component. Consequently, we developed a series of potent small-molecule inhibitors of CDK9, exemplified by the orally active A-1592668, with CDK selectivity profiles that are distinct from related molecules that have been extensively studied clinically. Short-term treatment with A-1592668 rapidly downregulates RNA pol-II (Ser 2) phosphorylation resulting in the loss of MCL-1 protein and apoptosis in MCL-1-dependent hematologic tumor cell lines. This cell death could be attenuated by either inhibiting caspases or overexpressing BCL-2 protein. Synergistic cell killing was also observed between A-1592668 or the related analog A-1467729, and venetoclax in a number of hematologic cell lines and primary NHL patient samples. Importantly, the CDK9 inhibitor plus venetoclax combination was well tolerated in vivo and demonstrated efficacy superior to either agent alone in mouse models of lymphoma and AML. These data indicate that CDK9 inhibitors could be highly efficacious in tumors that depend on MCL-1 for survival or when used in combination with venetoclax in malignancies dependent on MCL-1 and BCL-2.
Internal tandem duplication of the FMS-like tyrosine kinase 3 gene (
) occurs in 30% of all acute myeloid leukemias (AML). Limited clinical efficacy of FLT3 inhibitors highlights the need for ...alternative therapeutic modalities in this subset of disease. Using human and murine models of FLT3-ITD-driven AML, we demonstrate that FLT3-ITD promotes serine synthesis and uptake via ATF4-dependent transcriptional regulation of genes in the
serine biosynthesis pathway and neutral amino acid transport. Genetic or pharmacologic inhibition of PHGDH, the rate-limiting enzyme of
serine biosynthesis, selectively inhibited proliferation of FLT3-ITD AMLs
and
. Moreover, pharmacologic inhibition of PHGDH sensitized FLT3-ITD AMLs to the standard-of-care chemotherapeutic cytarabine. Collectively, these data reveal novel insights into FLT3-ITD-induced metabolic reprogramming and reveal a targetable vulnerability in FLT3-ITD AML. SIGNIFICANCE: FLT3-ITD mutations are common in AML and are associated with poor prognosis. We show that FLT3-ITD stimulates serine biosynthesis, thereby rendering FLT3-ITD-driven leukemias dependent upon serine for proliferation and survival. This metabolic dependency can be exploited pharmacologically to sensitize FLT3-ITD-driven AMLs to chemotherapy.
.
The BCL6 Corepressor (BCOR) is a component of a variant Polycomb repressive complex 1 (PRC1) that is essential for normal development. Recurrent mutations in the BCOR gene have been identified in ...acute myeloid leukaemia and myelodysplastic syndrome among other cancers; however, its function remains poorly understood. Here we examine the role of BCOR in haematopoiesis in vivo using a conditional mouse model that mimics the mutations observed in haematological malignancies. Inactivation of Bcor in haematopoietic stem cells (HSCs) results in expansion of myeloid progenitors and co-operates with oncogenic Kras
in the initiation of an aggressive and fully transplantable acute leukaemia. Gene expression analysis and chromatin immunoprecipitation sequencing reveals differential regulation of a subset of PRC1-target genes including HSC-associated transcription factors such as Hoxa7/9. This study provides mechanistic understanding of how BCOR regulates cell fate decisions and how loss of function contributes to the development of leukaemia.
Introduction: Improved treatments are needed for relapsed or refractory (R/R) non-Hodgkin lymphoma (NHL) pts. Options are particularly limited for pts with B-cell NHLs who are R/R to CAR-T therapies ...or for whom a delay in effective therapy precludes this approach. Mosunetuzumab (M; RG7828) is a full-length, fully humanized immunoglobulin G1 (IgG1) bispecific antibody targeting both CD3 (on the surface of T cells) and CD20 (on the surface of B cells). In an ongoing Phase I/Ib study (GO29781; NCT02500407), promising efficacy and favorable tolerability were observed in R/R NHL pts (Budde et al. ASH 2018; Bartlett et al. ASCO 2019). We report complete remissions (CRs) with M in NHL pts who are R/R to CAR-T therapy, as well as activity with M re-treatment.
Methods: GO29781 is an open-label, multicenter, Phase I/Ib, dose escalation and expansion study of M in R/R B-cell NHL. Data is presented from Group B, in which M is administered with step-up dosing on Days 1, 8, and 15 of Cycle 1, and then as a fixed dose on Day 1 of each subsequent 21-day cycle (maximum 17 cycles). Outcome measures include best objective response rate (ORR) by revised International Working Group criteria, maximum tolerated dose (MTD), and tolerability.
Results: As of June 4, 2019, 218 pts in Group B had received any amount of M. Indolent NHL (iNHL) pts (n=72) were mainly follicular lymphoma (FL, n=69). Aggressive NHL (aNHL) pts (n=141) were mainly diffuse large B-cell lymphoma (DLBCL, n=87) or transformed FL (trFL, n=29). Median prior systemic therapies was 3 (range: 1-14). Twenty-three pts had prior CAR-T therapy (12 DLBCL, 6 trFL, 5 FL), and 16 were efficacy evaluable (7 DLBCL, 5 trFL, 4 FL). ORR and CR rates were 43.8% (7/16) and 25.0% (4/16, 2 DLBCL and 2 FL), respectively. Expansion of previously administered CAR-Ts after M administration was detected by quantitative PCR, in line with the mechanism of action of M.
Dose escalation is ongoing, supported by a positive exposure-response relationship for efficacy and broad therapeutic window with step-up dosing (Li et al. ASH 2019). Among efficacy-evaluable pts across all dose levels, ORR and CR rates were 64.1% (41/64) and 42.2% (27/64) in iNHL pts and 34.7% (41/119) and 18.6% (22/119) in aNHL pts, respectively.
CRs appeared durable, with 25/27 (92.6%) iNHL pts (median time from first CR: 5.8 months; range: 0.2-28.9) and 15/22 (68.2%) aNHL pts (median time from first CR: 8.8 months; range: 0.0-25.4) who achieved CR remaining in remission. Re-treatment with M was allowed in CR pts who relapsed. Four pts, including 1 in Group A who was initially treated with a fixed, non-step-up dosing schedule, received M re-treatment. One CR and 2 partial responses were observed. All three responses are ongoing, with the CR pt in second remission for 314 days.
The MTD of M has not been reached at doses up to 1/2/60mg (Cycle 1 Day 1, 8, and 15). Adverse events (AEs) leading to treatment withdrawal were uncommon (12/218, 5.5%). Cytokine release syndrome (CRS), graded by Lee criteria (Lee et al. Blood 2014;124:188-95), was observed in 28.4% of pts, and was mostly Grade (Gr) 1 (21.1%) or Gr 2 (6.0%); Gr 3 CRS occurred in 1.4% of pts. Most CRS events occurred in Cycle 1; 5 pts (2.7%) had CRS during or after Cycle 2. Three of 218 pts (1.4%) received tocilizumab for CRS management; all 3 events resolved without sequelae (for 1 pt, CRS resolved after the cutoff date). Neurological AEs (NAEs) were reported in 44% of pts (Gr 1, 28.0%; Gr 2, 12.8%; Gr 3, 3.2%). Common NAEs were headache (14.7%), insomnia (10.1%), and dizziness (9.2%). Potential immune effector cell-associated neurotoxicity syndrome (ICANS)-like NAEs of Gr 1 or Gr 2 confusional state occurred in 3 pts (1.4%) during cycles 1 and 2. The frequency of CRS and NAEs did not correlate with M exposure, likely due to step-up dosing, which effectively mitigates acute toxicities and allows administration of higher doses (Bartlett et al. ASCO 2019; Li et al. ASH 2019). Among the 4 pts who were re-treated with M, no CRS was observed and NAEs were reported in 1 pt (Gr 1 headache and insomnia). Among the 23 pts who were R/R to CAR-T therapy, CRS occurred in 5 pts (21.7%; Gr 1, 13.0%; Gr 2, 4.3%; Gr 3, 4.3%) and NAEs in 8 pts (34.8%; Gr 1, 17.4%; Gr 2, 13.0%; Gr 3, 4.3%), with no ICANS-like events.
Conclusions: M has favorable tolerability and durable efficacy in pts with heavily pre-treated R/R B-cell NHL, including CRs in pts with disease progression after CAR-T therapies. Preliminary data support the possibility for re-treatment with M.
Schuster:Novartis: Honoraria, Patents & Royalties: Combination CAR-T and PD-1 Inhibitors, Research Funding; Nordic Nanovector: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Acerta: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Loxo Oncology: Consultancy, Honoraria; Merck: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Genentech: Consultancy, Honoraria, Research Funding. Bartlett:Bristol-Myers Squibb: Research Funding; Celgene: Research Funding; Kite Pharma: Research Funding; Merck: Research Funding; Millennium: Research Funding; Pfizer: Research Funding; Pharmacyclics: Research Funding; Gilead: Research Funding; Immune Design: Research Funding; Incyte: Research Funding; Janssen: Research Funding; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Affimed: Research Funding; Autolus: Research Funding; Forty Seven: Research Funding; Genentech, Inc.: Research Funding. Assouline:Janssen: Consultancy, Honoraria, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria, Speakers Bureau. Yoon:Kyowa Hako Kirin: Research Funding; Genentech, Inc.: Research Funding; Novartis: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; MSD: Consultancy; Janssen: Consultancy; Yuhan Pharma: Research Funding. Bosch:Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Acerta: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd/Genentech, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Sehn:Acerta: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Lundbeck: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Apobiologix: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Verastem: Consultancy, Honoraria; Merck: Consultancy, Honoraria; Merck: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Janssen-Ortho: Consultancy, Honoraria; Janssen-Ortho: Honoraria; TG Therapeutics: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria. Cheah:Janssen: Honoraria; Acerta: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; AbbVie: Research Funding; Celgene: Research Funding; Gilead: Honoraria; Loxo: Honoraria. Shadman:Mustang Biopharma: Research Funding; Gilead: Research Funding; AbbVIe: Consultancy, Research Funding; Genentech, Inc.: Consultancy, Research Funding; AstraZeneca: Consultancy; Sound Biologics: Consultancy; Pharmacyclics: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Atara: Consultancy; Bigene: Research Funding; Celgene: Research Funding; TG Therapeutics: Research Funding; Verastem: Consultancy; Acerta: Research Funding; Emergent: Research Funding; Sunesis: Research Funding; Merck: Research Funding. Gregory:MSD: Other: grant pending, Research Funding; Beigene: Other: Grant pending, Research Funding; Celgene: Other: grant pending, Research Funding; Monash University: Research Funding; Roche: Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees; AbbVie: Other: grant pending, Research Funding; Janssen: Other: grant pending, Research Funding; Melbourne Haematology: Consultancy, Honoraria, Other: Travel fees and conference support, Speakers Bureau. Wei:Genentech, Inc./F. Hoffmann-La Roche Ltd: Employment, Equity Ownership. Yin:Genentech, Inc: Employment, Equity Ownership. Kwan:Genentech, Inc: Employment, Equity Ownership. Yousefi:F. Hoffmann-La Roche Ltd: Employment. Hernandez:Genentech, Inc.: Employment, Equity Ownership. Li:F. Hoffmann-La Roche Ltd: Employment, Equity Ownership. O'Hear:F. Hoffmann-La Roche Ltd: Equity Ownership; Genentech, Inc.: Employment. Budde:F. H
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