Imide Drugs Research Articles

Novel potent molecular glue degraders against broad range of hematological cancer cell lines via multiple neosubstrates degradation

BackgroundTargeted protein degradation of neosubstrates plays a crucial role in hematological cancer treatment involving immunomodulatory imide drugs (IMiDs) therapy. Nevertheless, the persistence of inevitable drug resistance and hematological toxicities represents a significant obstacle to their clinical effectiveness.MethodsPhenotypic profiling of a small molecule compounds library in multiple hematological cancer cell lines was conducted to screen for hit degraders. Molecular dynamic-based rational design and cell-based functional assays were conducted to develop more potent degraders. Multiple myeloma (MM) tumor xenograft models were employed to investigate the antitumor efficacy of the degraders as single or combined agents with standard of care agents. Unbiased proteomics was employed to identify multiple therapeutically relevant neosubstrates targeted by the degraders. MM patient-derived cell lines (PDCs) and a panel of solid cancer cell lines were utilized to investigate the effects of candidate degrader on different stage of MM cells and solid malignancies. Unbiased proteomics of IMiDs-resistant MM cells, cell-based functional assays and RT-PCR analysis of clinical MM specimens were utilized to explore the role of BRD9 associated with IMiDs resistance and MM progression.ResultsWe identified a novel cereblon (CRBN)-dependent lead degrader with phthalazinone scaffold, MGD-4, which induced the degradation of Ikaros proteins. We further developed a novel potent candidate, MGD-28, significantly inhibited the growth of hematological cancer cells and induced the degradation of IKZF1/2/3 and CK1α with nanomolar potency via a Cullin-CRBN dependent pathway. Oral administration of MGD-4 and MGD-28 effectively inhibited MM tumor growth and exhibited significant synergistic effects with standard of care agents. MGD-28 exhibited preferentially profound cytotoxicity towards MM PDCs at different disease stages and broad antiproliferative activity in multiple solid malignancies. BRD9 modulated IMiDs resistance, and the expression of BRD9 was significant positively correlated with IKZF1/2/3 and CK1α in MM specimens at different stages. We also observed pronounced synergetic efficacy between the BRD9 inhibitor and MGD-28 for MM treatment.ConclusionsOur findings present a strategy for the multi-targeted degradation of Ikaros proteins and CK1α against hematological cancers, which may be expanded to additional targets and indications. This strategy may enhance efficacy treatment against multiple hematological cancers and solid tumors.

Asymmetric Dirhodium-Catalyzed Modification of Immunomodulatory Imide Drugs and Their Biological Assessment.

Cereblon (CRBN) has been successfully co-opted to affect the targeted degradation of "undruggable" proteins with immunomodulatory imide drugs (IMiDs). IMiDs act as molecule glues that facilitate ternary complex formation between CRBN and a target protein, leading to ubiquitination and proteasomal degradation. Subtle structural modifications often cause profound and sometimes unpredictable changes in the degradation selectivity. Herein, we successfully utilize enantioselective cyclopropanation and cyclopropenation on intact glutarimides to enable the preparation of stereochemically and regiochemically matched molecular pairs for structure-activity relationship (SAR) analysis across several classical CRBN neosubstrates. The resulting glutarimide analogs were found to reside in unique chemical space when compared to other IMiDs in the public domain. SAR studies revealed that, in addition to the more precedented impacts of regiochemistry, stereochemical modifications far from the glutarimide can lead to divergent neosubstrate selectivity. These findings emphasize the importance of enabling enantioselective methods for glutarimide-containing compounds to tune the degradation selectivity.

Immunomodulatory imide drugs inhibit human detrusor smooth muscle contraction and growth of human detrusor smooth muscle cells, and exhibit vaso-regulatory functions

BackgroundThe immunomodulatory imide drugs (IMiDs) thalidomide, lenalidomide and pomalidomide may exhibit therapeutic efficacy in the prostate. In lower urinary tract symptoms (LUTS), voiding and storage disorders may arise from benign prostate hyperplasia, or overactive bladder. While current therapeutic options target smooth muscle contraction or cell proliferation, side effects are mostly cardiovascular. Therefore, we investigated effects of IMiDs on human detrusor and porcine artery smooth muscle contraction, and growth-related functions in detrusor smooth muscle cells (HBdSMC). MethodsCell viability was assessed by CCK8, and apoptosis and cell death by flow cytometry in cultured HBdSMC. Contractions of human detrusor tissues and porcine interlobar and coronary arteries were induced by contractile agonists, or electric field stimulation (EFS) in the presence or absence of an IMID using an organ bath. Proliferation was assessed by EdU assay and colony formation, cytoskeletal organization by phalloidin staining, ResultsDepending on tissue type, IMiDs inhibited cholinergic contractions with varying degree, up to 50 %, while non-cholinergic contractions were inhibited up to 80 % and 60 % for U46619 and endothelin-1, respectively, and EFS-induced contractions up to 75 %. IMiDs reduced viable HBdSM cells in a time-dependent manner. Correspondingly, proliferation was reduced, without showing pro-apoptotic effects. In parallel, IMiDs induced cytoskeletal disorganization. ConclusionsIMiDs exhibit regulatory functions in various smooth muscle-rich tissues, and of cell proliferation in the lower urinary tract. This points to a novel drug class effect for IMiDs, in which the molecular mechanisms of action of IMiDs merit further consideration for the application in LUTS.

Preclinical Evaluation of a Novel Series of Polyfluorinated Thalidomide Analogs in Drug-Resistant Multiple Myeloma.

Immunomodulatory imide drugs (IMiDs) play a crucial role in the treatment landscape across various stages of multiple myeloma. Despite their evident efficacy, some patients may exhibit primary resistance to IMiD therapy, and acquired resistance commonly arises over time leading to inevitable relapse. It is critical to develop novel therapeutic options to add to the treatment arsenal to overcome IMiD resistance. We designed, synthesized, and screened a new class of polyfluorinated thalidomide analogs and investigated their anti-cancer, anti-angiogenic, and anti-inflammatory activity using in vitro and ex vivo biological assays. We identified four lead compounds that exhibit potent anti-myeloma, anti-angiogenic, anti-inflammatory properties using three-dimensional tumor spheroid models, in vitro tube formation, and ex vivo human saphenous vein angiogenesis assays, as well as the THP-1 inflammatory assay. Western blot analyses investigating the expression of proteins downstream of cereblon (CRBN) reveal that Gu1215, our primary lead candidate, exerts its activity through a CRBN-independent mechanism. Our findings demonstrate that the lead compound Gu1215 is a promising candidate for further preclinical development to overcome intrinsic and acquired IMiD resistance in multiple myeloma.

Targeted protein degradation in CNS disorders: a promising route to novel therapeutics?

Targeted protein degradation (TPD) is a rapidly expanding field, with various PROTACs (proteolysis-targeting chimeras) in clinical trials and molecular glues such as immunomodulatory imide drugs (IMiDs) already well established in the treatment of certain blood cancers. Many current approaches are focused on oncology targets, leaving numerous potential applications underexplored. Targeting proteins for degradation offers a novel therapeutic route for targets whose inhibition remains challenging, such as protein aggregates in neurodegenerative diseases. This mini review focuses on the prospect of utilizing TPD for neurodegenerative disease targets, particularly PROTAC and molecular glue formats and opportunities for novel CNS E3 ligases. Some key challenges of utilizing such modalities including molecular design of degrader molecules, drug delivery and blood brain barrier penetrance will be discussed.

Anhydrous and Stereoretentive Fluoride-Enhanced Suzuki-Miyaura Coupling of Immunomodulatory Imide Drug Derivatives.

Immunomodulatory imide drugs form the core of many pharmaceutically relevant structures, but Csp2-Csp2 bond formation via metal-catalyzed cross coupling is difficult due to the sensitivity of the glutarimide ring ubiquitous in these structures. We report that replacement of the traditional alkali base with a fluoride source enhances a previously challenging Suzuki-Miyaura coupling on glutarimide-containing compounds with trifluoroborates. These enabling conditions are reactive enough to generate these derivatives in high yields but mild enough to preserve both the glutarimide and its sensitive stereocenter. Experimental and computational data suggest a mechanistically distinct process of π-coordination of the trifluoroborate enabled by these conditions.

Development of Phenyl-substituted Isoindolinone- and Benzimidazole-type Cereblon Ligands for Targeted Protein Degradation.

Thalidomide, pomalidomide and lenalidomide, collectively referred to as immunomodulatory imide drugs (IMiDs), are frequently employed in proteolysis-targeting chimeras (PROTACs) as cereblon (CRBN) E3 ligase-recruiting ligands. However, their molecular glue properties that co-opt the CRL4CRBN to degrade its non-natural substrates may lead to undesired off-target effects for the IMiD-based PROTAC degraders. Herein, we reported a small library of potent and cell-permeable CRBN ligands, which exert high selectivity over the well-known CRBN neo-substrates of IMiDs by structure-based design. They were further utilized to construct bromodomain-containing protein 4 (BRD4) degraders, which successfully depleted BRD4 in the tested cells. Overall, we reported a series of functionalized CRBN recruiters that circumvent the promiscuity from traditional IMiDs, and this study is informative to the development of selective CRBN-recruiting PROTACs for many other therapeutic targets.

Mitigating chronic neuroinflammation in Alzheimer mice by novel immunomodulatory imide drugs (IMiDs) conserves neuroplasticity and cognitive function and also alleviates neurodegeneration‐behavioral impairments in TBI‐challenged mice

AbstractBackgroundNeuroinflammation is an invariable characteristic of chronic neurodegenerative disorders, such as Alzheimer’s disease (AD), and acute ones, epitomized by traumatic brain injury (TBI). However, whether neuroinflammation development drives disease progression or is an epiphenomenon remains unknown.MethodsTo test the hypothesis that, once initiated, AD‐associated chronic neuroinflammation directly drives progressive synaptic/neuronal loss and cognitive decline irrespective of changes in amyloid‐β (Aβ) peptide generation, a new class of immunomodulatory imide drugs (IMiDs) was developed on the backbone of thalidomide/pomalidomide to reduce proinflammatory cytokine generation and resulting inflammation, but lacking action on SALL4 – a key protein implicated in thalidomide teratogenicity. (i) 5xFAD mice, known to develop neuroinflammation consequent to excessive Ab generation, were evaluated over a 4‐month period during which cognitive deficits develop, and (ii) wild type mice subjected to TBI and impacted with motor and cognitive impairments were evaluated to assess whether selective resolution of neuroinflammation by novel IMiDs could mitigate behavioral declines.ResultsPomalidomide (Pom) and the more potent novel analog, 3,6’‐dithioPom (3,6’‐DP), which does not impact SALL4 levels, were administered to reduce microglial cell activation ‐ as confirmed in primary cortical cultures challenged with Aβ and RAW 264.7 cells challenged with lipopolysaccharide (LPS). 3,6’‐DP, in particular, decreased microglial and astrocyte activation in hippocampus and cerebral cortex of 5xFAD mice. This was accompanied by reductions in synaptic and neuronal cell loss, and behavioral impairment in the absence of changes in Aβ plaque or peptide generation. In TBI challenged mice, 3,6’‐DP, likewise, mitigated neuroinflammation and resulted in reduced neuronal loss and behavioral impairments.ConclusionsAD‐associated chronic neuroinflammation directly drives progressive synaptic/neuronal loss and cognitive decline. Pharmacologically mitigating microglial/astrocyte activation without altering Aβ generation provides a means to mitigate AD‐associated cognitive/behavioral impairments, and provides a new drug candidate to alleviate other neurodegenerative disorders, such as TBI.

Real-World Progression-Free Survival and Treatment Patterns for t(11;14) Positive Patients with Multiple Myeloma with at Least 2 Prior Lines of Treatment

Background : Multiple myeloma (MM) is a subclonal disease characterized by large heterogeneity with a complex treatment landscape. Patients with MM have a myriad of available treatment options, prescribed based on several factors, including genetic testing, comorbidities, risk status, age, patient preference, and/or prior treatment failures. Cytogenetic abnormalities determines risk stratification and prognosis. The prognostic significance of t(11;14)-positivity has been debated and it is currently considered a standard-risk abnormality; however, testing for t(11;14) may be of potential therapeutic significance. Despite recent advances in treatment that have improved response rates and survival, MM remains incurable. This results in a continuous treat-to-failure approach that eventually leads to a lack of effective therapeutic options. Treatment patterns and outcomes for patients by lines of therapy (LOT) in real-world settings provide important benchmarks for assessments of future targeted therapies. Methods : Data were retrospectively collected from the ConcertAI Patient360 database containing aggregated electronic health record data of patients treated in primarily community-based oncology centers in the US. Adults diagnosed with MM (2011-2022) who received a National Comprehensive Cancer Network-guideline recommended treatment and had ≥2-months follow up were included; this analysis focused on patients with relapsed or refractory (RR) MM who are t(11;14)-positive and received ≥2 prior lines of systemic therapy. Baseline characteristics were determined for the third-line plus (3L+) subgroup of patients with t(11;14) RRMM. Real-world progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Results were stratified by the use of doublet or triplet regimens, in which patients were treated with 2 or 3 classes of treatments among 6 options (ie, proteasome inhibitors [PI], immunomodulatory imide drugs [IMID], anti-CD38 monoclonal antibodies, chemotherapy, BCL-2 inhibitors, exportin-1 inhibitors, or steroid therapy), respectively, at any time during the LOT. Results : Eighty-four patients with t(11;14) RRMM received 3L+ of therapy. Of patients, 43% were female, 20% were Black, and 75% were White. The median (range) age at diagnosis was 64 (37-84), and the median (range) follow-up since diagnosis was 76 (10-209) months. At 24 months since the initiation of treatment, the median (range) PFS for all t(11;14)-positive patients that received 3L+ of therapy was 7.5 (5.9-9.4) months, and the median (range) PFS rate was 14.8% (9.7%-22.5%) (Figure); the median (range) OS for all t(11;14)-positive patients that received 3L+ of therapy was 32.1 (25.4-48.0) months, and the median (range) OS rate was 58.3% (51.0%-66.6%). The most common treatment regimens used in 3L+ included Daratumumab + Pomalidomide ± Dexamethasone (12%), Venetoclax monotherapy (9%), Pomalidomide ± Dexamethasone (7%), and Bortezomib ± Dexamethasone (7%). Of doublet regimens used in 3L+ (n = 69 LOT), 18 (26%) were IMID + steroid, 14 (20%) were PI + steroid, and 11 (16%) monoclonal antibody (MA)+ steroid. For triplet regimens used at 3L+ (n = 97 LOT), 28 (29%) were IMID + MA + steroid, 23 (24%) were IMID + PI + steroid, and 12 (12%) were MA + PI + steroid. Triplet regimen use increased from 52% in 3L to 61% in 4L and was associated with slightly longer PFS in 3L, relative to doublet regimen use. For patients that received 3L+ therapies, the median (95% CI) PFS was 6.7 (5.4-11.1) months for patients receiving doublet regimens, and 7.7 (5.9-11.3) months for patients receiving triplet regimens. Conclusions: Triplet regimens were more commonly used than doublet regimens as 3L+ therapy. Triplets were also associated with slightly longer PFS in 3L; however, PFS rates were low and did not translate into longer OS, suggesting an unmet need for novel therapeutic options for patients with t(11;14) RRMM.

Targeting the Oncofetal Transcription Factor Protein SALL4 in Cancer By a Non-IMiD Degrader

Sal-like protein 4 (SALL4) is a C2H2 zinc finger transcription factor (TF) with two naturally occurring isoforms; SALL4A and SALL4B. It is typically detected in fetal tissues and silenced in most normal adult tissues. It is therefore intriguing that SALL4 is aberrantly re-expressed in about one-third of almost all primary human malignancies, presumably by demethylation dependent mechanisms. Direct evidence of the causative role of SALL4 in cancer has been demonstrated in SALL4 transgenic mice, which developed myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and/or liver tumors. Loss-of-function studies by SALL4 knock-down using shRNA showed cell growth inhibition and death in leukemias and solid tumors in culture and in in vivo xenotransplants. TF's, such as SALL4, which are critical for cancer development and survival, have historically been viewed as “undruggable”. However, rather than blocking activity, an alternative approach to target TFs is to induce protein degradation. Immunomodulatory imide drugs (IMiDs), including thalidomide, lenalidomide and pomalidomide, are used in treating patients with multiple myeloma (MM), MDS with 5q deletion, mantle cell lymphoma (MCL), and other hematological malignancies. Recently, several groups have reported that IMiDs can degrade SALL4 in a proteasome-dependent manner. To that end, we sought to investigate whether IMiDS could be utilized to treat SALL4-positive/expressing cancers. Initially, our studies observed that IMiDs had no effect on SALL4-positive cancer cells. Additional investigations thereafter demonstrated that IMiDs could only degrade SALL4A. These findings suggested that SALL4B may not be affected by IMiDs, and may be essential for SALL4-mediated cancer cell survival. Further investigation revealed that SALL4B knockdown led to an increase in apoptosis and inhibition of cancer cell growth. Moreover, through high-throughput screening, we identified a new non-IMiD SALL4 degrader that targets SALL4B via proteasomal degradation and which exhibited potent anti-cancer activity, inhibiting cancer cell proliferation in culture and in vivotumor growth by 70%. Our observation therefore suggest that protein degraders could possess isoform specific effects. Additionally, our results exemplify the importance of delineating drug action and oncogenesis at the isoform level to develop more effective cancer therapeutics.

Anti-Leukemic Effects of CK1α Degrader As Monotherapy and in Combination with Targeted Drugs

CK1⍺ is a member of casein kinase 1 (CK1) family, a multifunctional serine/threonine kinase conserved in eukaryotes from yeast to humans. Substrates of CK1⍺ include various proteins important in cancer and regulate multiple survival pathways such as p53, Wnt, autophagy and NF-B signaling pathways. In particular, CK1- serves as an upstream regulator of p53 pathway through regulation of MDM2 and MDMX and degradation of CK1- may prevent MDM2 and/or MDMX mediated inactivation of p53 function, thus facilitate cell death. We identified an early hit compound, distinct from known immunomodulatory imide drugs (IMiDs) such as lenalidomide or thalidomide. In order to identify compounds having distinct characteristic with previously published IMiDs, we designed multiple compounds with a wide range of glue effect based on the binding mode analysis and binding structure of CRBN and known IMiDs. Among them, PinA1 (early lead compound) selectively degraded CK1-, in the nanomolar range with the highest potency. PinA1 induced expression of p53 which led to apoptosis in AML cell lines with wild-type TP53 (MV4-11, MOLM-13, and MOLM-14), but not in TP53 mutated cells (KASUMI-1, and KG-1). Of note, in TP53 wild-type cells, expression of MDM2 and p21 increased as well, which may limit p53-induced apoptosis in these cells. PinA1 also induced CK1- degradation and p53-dependent apoptosis in primary AML cells in vitro. On the other hand, PinA1 had marginal effects on the viability of human peripheral blood mononuclear cells and CD34+ cells, with minimal activation of the p53 pathway at an efficacious dose range for MV4-11 compared to MDM2 inhibitors. PinA1 enhanced apoptosis in combination with FLT3, BCL-2, or MDM2 inhibitors in AML cell lines (MV4-11, MOLM-14) and primary AML cells in vitro. To test the efficacy of PinA1 in vivo, we injected MOLM-14/ luc/GFP or MV4-11/ luc/Thy1.1 into nonirradiated NGS mice. Five or Six days after cell injection, mice were randomized into 4 groups: vehicle, PinA1, and PinA1 plus AMG232 (MDM2 inhibitor), venetoclax, or gilteritinib. Bioluminescence imaging (BLI) demonstrated significantly less leukemia burden in all treated groups than vehicles; leukemia progression was lowest with combination therapy. Flow cytometry with sacrificed mice revealed the lowest leukemia burden in combination therapy, consistent with those from BLI. Western blotting with sorted leukemic cells from bone marrow and spleen revealed CK1- degradation in vivo. PinA1- and other single drug-treated mice had prolonged survival compared with vehicles, and combination therapy extended survival even further. Patient-derived xenograft models from two FLT3-ITD-mutated AML patients also showed potent anti-leukemic effects of PinA1 as monotherapy and in combination with gilteritinib. In conclusion, our study showed that PinA1 selectively degrades CK1α, enhancing expression of p53, which then induces apoptosis in TP53-wild-type AML cells, but not in TP53-mutated AML cells, thereby producing anti-leukemic effects as monotherapy or in combination with targeted therapies. The minimal effect of PinA1 on normal hematopoietic cells may positively contribute to safety in future clinical trials. This novel targeting approach may improve the current targeted therapies in combination once validated.

Comparative Effectiveness of Axicabtagene Ciloleucel Vs Historical Standard-of-Care in Patients with Relapsed or Refractory Follicular Lymphoma: An Analysis of CIBMTR and SCHOLAR-5 Data

Background: Axicabtagene ciloleucel (axi-cel), an autologous chimeric antigen receptor (CAR) T-cell therapy, achieved an overall response rate (ORR) of 94% and a complete response (CR) rate of 79% in patients with relapsed or refractory (r/r) follicular lymphoma (FL) after two or more prior lines of therapy in the ZUMA-5 trial ( Jacobson et al. Lancet Oncol. 2022). Since its FDA approval in March 2021, there has been little evidence on comparative effectiveness (CE) studies of axi-cel vs standard-of-care (SoC), except ones using ZUMA-5 and historical SCHOLAR-5 data (eg, Ghione et al. Blood. 2022). This study was aimed to address this evidence gap in CE of axi-cel vs SoC used to treat r/r FL in real-world settings. Methods: The two data sources in this study were patients who received commercial axi-cel between March 2021 and May 2023 from the CIBMTR and patients who received historical SoC (eg, chemotherapy, anti-CD20 mAb + chemotherapy, immunomodulatory imide drugs) between July 2014 and December 2020 from SCHOLAR-5, which served as an external control of ZUMA-5 trial. The index date was defined as the initiation date of either the infusion for axi-cel patients or the last eligible systemic therapy for SoC patients. Patients were included if they were age ≥ 18, had documented r/r FL with histological grade 1, 2 or 3a, and received at least 2 prior lines of therapy at the index. Patients were excluded if they had transformed diffused large B-cell lymphoma, central nervous system involvement, prior receipt of CAR T or other non-CAR T cellular therapies or allogeneic stem cell transplant, or no post-index information on outcomes. Four effectiveness outcomes were ORR, CR rate, progression-free survival (PFS), and overall survival (OS). Imbalance in observed prognostic risk factors between the two was adjusted via a propensity score analysis using the standard mortality ratio weighting (SMRW). The primary analyses included weighted univariable analysis and multivariable logistic (ORR and CR rate) or Cox (PFS and OS) regressions that were adjusted for the covariates after the SMRW. A sub-analysis of patients age ≥ 65 was conducted using the same methods as the primary analyses. Results: The unweighted study cohort included 376 patients, in which 256 (68%) received axi-cel . Thepatients who received axi-cel were more likely to be younger (median age 61 for axi-cel vs 67 for SoC), have grade 3a FL (37% vs 12%), received 3 or more prior lines of therapy (83% vs 58%), or remained refractory to the last prior therapy (79% vs 73%) vs those who received SoC. The imbalance in the observed prognostic risk factors was mitigated via the SMRW. The weighted univariable analysis, in which the sample size by treatment reflected the SMRW, is shown in Table 1. In patients of all ages, ORR was 92% in axi-cel vs 67% in SoC, and CR rate was 84% vs 37%. Because of varying follow-up lengths by treatment (median 7 months for axi-cel and 37 months for SoC), survival outcomes were reported at month 6, at which time PFS rate was 88% in axi-cel vs 64% in SoC and OS rate was 97% vs 85%. The corresponding proportions for patients age ≥ 65 were similar to those reported for patients of all ages. In the weighted multivariable regressions, axi-cel was associated with statistically significantly better outcomes by all 4 effectiveness measures vs SoC (Table 1). Specifically, in patients of all ages, the odds ratios for axi-cel were 4.93 (95% CI, 2.35−10.34) for ORR and 16.72 (95% CI, 7.03−39.73) for CR rate, and the hazard ratios for axi-cel were 0.41 (95% CI, 0.22−0.77) for PFS and 0.15 (95% CI, 0.06−0.34) for OS. Similar to the patients of all ages in the primary analyses, patients age ≥ 65 in the sub-analysis also demonstrated improved outcomes associated with axi-cel (Figure 1). Conclusions: This study showed that patients with r/r FL after two or more prior lines of therapy treated with axi-cel experienced better outcomes compared with patients treated with SoC, and that older patients also benefited significantly from axi-cel. These findings suggest that axi-cel addresses an important unmet medical need in patients with r/r FL. Future research should include longer follow-up data on outcomes of axi-cel and CE of axi-cel vs other contemporary SoC therapies.

SOR-CART-MM-001 Study: A Phase I, Open-Label, Dose-Escalation, Pharmacokinetic, and Pharmacodynamic Study of Safety and Efficacy of CAR2 Anti-CD38 A2 CAR-T Cells in Patients with Relapsed or Refractory Multiple Myeloma (RRMM)

Background: B-cell maturation antigen (BCMA) directed chimeric antigen receptor (CAR-) T cells, show high response rates in patients with highly refractory and heavily treated myeloma, and have become a standard treatment in this setting. The durability of these responses, however, has been limited with few long term remissions. One approach to potentially improve CAR T outcome is to direct these cells to alternative targets such as CD38 almost universally expressed on malignant plasma cells. In this open-label phase I multi-institutional study we explored the efficacy and safety of CAR2 anti-CD38 A2 CAR-T cells in patients with RRMM. Methods: The SOR-CART-MM-001 study was a multicenter, open-label, “3+3” dose-escalation, phase 1b trial of a single administration of a fully human antibody with lambda light chain generated by transduction of activated T cells with an anti-CD38 A2 CAR expressing retroviral vector. A single dose of CAR2 Anti-CD38 CAR-T cells was administered 2 days post lymphodepletion with single-agent cyclophosphamide 1.5 g/m 2. The primary endpoint was determination of the maximum tolerated dose (MTD) assessed by the occurrence of treatment-emergent dose-limiting toxicities during the 28-day treatment period in the dose-escalation phase of the study. Dosing was divided into three cohorts ranging from 1 × 10 5 cells/kg (Cohort 1) to 1 × 10 7 cells/kg (Cohort 3). Circulating CAR-T cells were measured at different timepoints post infusion. Key eligibility criteria included ≥3 lines of therapy with prior proteasome inhibitor, immunomodulatory IMID drug or daratumumab exposure, measurable and progressive MM per International Myeloma Working Group criteria and ECOG ≤ 2. Results: Between March 2018 and March 2022, 9 patients were enrolled and assigned to each of the three Cohorts. Patient demographics and baseline characteristics are described in Table 1. Hematologic toxicity was the most common treatment emergent adverse event experienced (6/9, 66.7%), all Grade 3 or Grade 4. All cytopenias recovered in 21 days in subjects treated with no more than MTD. Two subjects within Cohort 3 exhibited mild cytokine release syndrome (CRS) (Grade 1 and 2) with one of these two subjects also developing mild neurotoxicity (Grade 2). No CRS or neurotoxicity was observed at either of the lower dose levels. Two serious adverse events (SAEs) were reported: Klebsiella sepsis 60 days after treatment that recovered in 4 days after antibiotics and muscle weakness at 24 days after treatment that received within 1 day without treatment and neither were deemed related to the study medication. The first 2 patients in Cohort 3 met dose limiting toxicity (DLT) criteria after treatment due to grade 3 hematological toxicity and the next lower dose 1 x 10 6 cells/kg (Cohort 2) became the MTD. Pharmacokinetic data showed the percentage of the detectable circulating CAR-T cells in any subject at any time point was low with many showing no detectable cells. 4 deaths were reported after the end of the study period, and none were considered related to the investigated CAR-T cells (3 due to progression and one due to COVID-19). Overall, a total of 3 patients had a partial response (PR) and 3 patients had stable disease (SD) across 3 dose levels. PR constituted the best response in the study and the durations of objective clinical responses were each less than 3 months. These treatment responses are summarized in Table 2. Conclusion: This phase I trial demonstrated that CAR2 anti-CD38 A2 CAR-T cells were generally well tolerated at the Cohort 2 (MTD) dose and demonstrated objective though short responses even in patients progressing after daratumumab and belantamab mafodotin. More clinical studies are needed to optimize the efficacy and tolerability of CAR-T cell therapies for patients with RRMM. This study was completed, and no more patients will be enrolled. DART-RRMM-101 is a phase 1b, open-label, dose-escalation study ongoing to assess allogeneic Anti-CD38 A2 Dimeric Antigen Receptor T Cells in RRMM (ClinicalTrials: NCT05007418).

Leveraging Ligand Affinity and Properties: Discovery of Novel Benzamide-Type Cereblon Binders for the Design of PROTACs.

Immunomodulatory imide drugs (IMiDs) such as thalidomide, pomalidomide, and lenalidomide are the most common cereblon (CRBN) recruiters in proteolysis-targeting chimera (PROTAC) design. However, these CRBN ligands induce the degradation of IMiD neosubstrates and are inherently unstable, degrading hydrolytically under moderate conditions. In this work, we simultaneously optimized physiochemical properties, stability, on-target affinity, and off-target neosubstrate modulation features to develop novel nonphthalimide CRBN binders. These efforts led to the discovery of conformationally locked benzamide-type derivatives that replicate the interactions of the natural CRBN degron, exhibit enhanced chemical stability, and display a favorable selectivity profile in terms of neosubstrate recruitment. The utility of the most potent ligands was demonstrated by their transformation into potent degraders of BRD4 and HDAC6 that outperform previously described reference PROTACs. Together with their significantly decreased neomorphic ligase activity on IKZF1/3 and SALL4, these ligands provide opportunities for the design of highly selective and potent chemically inert proximity-inducing compounds.

Outcomes After Salvage Autologous Hematopoietic Cell Transplant for Patients With Relapsed/Refractory Multiple Myeloma: A Single-Institution Experience.

The role of salvage autologous hematopoietic cell transplantation (sAHCT2) for patients with relapsed/refractory multiple myeloma (RRMM) in the era of modern therapeutics is unclear. As prospective data is limited, we conducted a retrospective analysis to determine the outcomes of sAHCT2. We conducted a single-institution, retrospective analysis of patients who received sAHCT2 at The Ohio State University from 2000 to 2018. Patients who received a second transplant as part of a planned tandem or autologous-allogeneic transplant were excluded. Fifty-seven patients were treated with sAHCT2. Patients had a median of 2 lines of therapy after AHCT1 prior to their sAHCT2; 70% had prior immunomodulatory imide drugs, 82% had prior proteasome inhibitor, and 20% had prior anti-CD38 monoclonal antibodies as part of re-induction therapy. Forty-two percent of patients attained ≥VGPR prior to sAHCT2. Seventy-four were treated with melphalan 200 mg/m2 as conditioning regimen before infusion of a median of 3.8×106 CD34+ cells/kg. Fifty-eight percent patients had maintenance therapy and 81% patients attained CR/VGPR as the best response after sAHCT2. The median PFS and OS after sAHCT2 were 1.6 and 3.6 years, respectively. On multivariable analysis, high-risk cytogenetics, not having attained CR/VGPR, and having more than 2 lines of therapy post-AHCT1 were associated with inferior PFS. Melphalan 140 mg/m2 compared to melphalan 200 mg/m2 and no maintenance therapy compared to maintenance therapy were not associated with inferior PFS. There was no transplant-related mortality in this patient cohort. For MM patients deriving durable remission after their AHCT1, sAHCT2 was safe and resulted in deep and durable remissions.

Inhibition of human detrusor smooth muscle cell growth and modulation of cytoskeletal organization by Immuno-Modulatory Imide Drugs (IMIDs)

Inhibition of human detrusor smooth muscle cell growth and modulation of cytoskeletal organization by Immuno-Modulatory Imide Drugs (IMIDs)

Outcomes of SARS-CoV-2 infection in Ph-neg chronic myeloproliferative neoplasms: results from the EPICOVIDEHA registry.

Patients with Philadelphia-negative chronic myeloproliferative neoplasms (MPN) typically incur high rates of infections and both drugs and comorbidities may modulate infection risk. The present study aims to assess the effect of immunosuppressive agents on clinical outcomes of MPN patients affected by the coronavirus disease 2019 (COVID-19). This is an observational study. We specifically searched and analyzed MPN patients collected by EPICOVIDEHA online registry, which includes individuals with hematological malignancies diagnosed with COVID-19 since February 2020. Overall, 398 patients with MPN were observed for a median of 76 days [interquartile range (IQR): 19-197] after detection of SARS-CoV2 infection. Median age was 69 years (IQR: 58-77) and 183 individuals (46%) had myelofibrosis (MF). Overall, 121 patients (30%) of the whole cohort received immunosuppressive therapies including steroids, immunomodulatory drugs, or JAK inhibitors. Hospitalization and consecutive admission to intensive care unit was required in 216 (54%) and 53 patients (13%), respectively. Risk factors for hospital admission were identified by multivariable logistic regression and include exposure to immunosuppressive therapies [odds ratio (OR): 2.186; 95% confidence interval (CI): 1.357-3.519], age ⩾70 years, and comorbidities. The fatality rate was 22% overall and the risk of death was independently increased by age ⩾70 years [hazard ratio (HR): 2.191; 95% CI: 1.363-3.521], previous comorbidities, and exposure to immunosuppressive therapies before the infection (HR: 2.143; 95% CI: 1.363-3.521). COVID-19 infection led to a particularly dismal outcome in MPN patients receiving immunosuppressive agents or reporting multiple comorbidities. Therefore, specific preventive strategies need to be tailored for such individuals. EPICOVIDEHA registry reports inferior outcomes of COVID-19 in patients with Philadelphia-negative chronic myeloproliferative neoplasms receiving immunosuppressive therapies. Patients with Philadelphia-negative chronic myeloproliferative neoplasms (MPN) incur high rates of infections during the course of their disease.The present study was aimed at assessing which patient characteristics predicted a worse outcome of SARS-COV-2 infection in individuals with MPN.To pursue this objective, the researchers analyzed the data collected by EPICOVIDEHA, an international online registry, which includes individuals with hematological malignancies diagnosed with COVID-19 since February 2020.The database provided clinical data of 398 patients with MPN incurring COVID-19:Patients were mostly elderly (median age was 69 years);Forty-six percent of them were affected by myelofibrosis, which is the most severe MPN;Moreover, 32% were receiving immunosuppressive therapies (JAK inhibitors, such as ruxolitinib, steroids, or immunomodulatory IMID drugs, such as thalidomide) before COVID-19.Hospitalization was required in 54% of the patients, and the risk of being hospitalized for severe COVID-19 was independently predicted byOlder age;Comorbidities;Exposure to immunosuppressive therapies.Overall, 22% of MPN patients deceased soon after COVID-19 and the risk of death was independently increased over twofold byOlder age;Comorbidities;Exposure to immunosuppressive therapies before the infection.In conclusion, COVID-19 infection led to a particularly dismal outcome in MPN patients receiving immunosuppressive agents, including JAK inhibitors, or reporting multiple comorbidities. Therefore, specific preventive strategies need to be tailored for such individuals.

Targeting neuroinflammation reduces synaptic, neuronal and cognitive loss in 5xFAD Alzheimer mice.

AbstractBackgroundNeuroinflammation is a consistent characteristic of Alzheimer’s disease (AD); however, whether its development drives disease progression or is an epiphenomenon remains unknown (Gyengesy et al., 2020). In this study, we evaluated how treatment with the Immunomodulatory imide drugs (IMiDs) Pomalidomide (Pom) and more potent novel analog 3,6’‐dithioPomalidomide (3,6’‐DP) affects neuronal and synaptic loss as well as cognitive impairment in a 5xFAD transgenic mouse model of AD, by targeting neuroinflammation. These mice are known to develop neuroinflammation consequent to excessive amyloid‐b (Ab) peptide generation.MethodAs a first step, Pom and 3,6’‐DP neuroprotective and anti‐inflammatory potential were characterized on primary cell cultures challenged with Ab. 5xFAD mice were evaluated over a 4‐month period, during which cognitive deficits develop. Behavioral tests were performed to establish whether selective resolution of neuroinflammation could mitigate cognitive impairment. Pom and 3,6’‐DP effects were assessed on markers of neuronal death, microglial activation, astrogliosis, and expression of PSD‐95 post‐synaptic protein. Changes in levels of inflammatory cytokines and Ab in hippocampus and cortex 5xFAD mice were also measured. Lastly, the teratogenic potential of both compounds was appraised by a cereblon/BRD3 binding FRET assay.ResultPom and 3,6’‐DP reduced neuronal and neurite network loss, as well as microglial cell activation in primary cortical cultures challenged with Ab. In hippocampus and cerebral cortex of 5xFAD mice, 3,6’‐DP, in particular, mitigated elevated expression of Iba1, TNF‐a and GFAP proteins, markers of microglial and astrocyte activation. This was accompanied by reductions in synaptic and neuronal cell loss as well as mitigation of behavioral impairment but, notably, no alteration in either Ab plaque or peptide generation. Both 3,6’‐DP and Pom bound cereblon; however, 3,6’‐DP did not lower Ikaros, Aiolos or SALL4, which are key downstream neo‐substrates involved in the anticancer and teratogenic actions of the IMiD drug class. Hence, 3,6’‐DP could represent a potentially safer drug to lower TNF‐a levels.ConclusionMitigating neuroinflammation in the absence of actions on Ab generation to alleviate neurodegeneration and behavioral impairment indicates that neuroinflammation is a primary causative event in the Ab‐mediated pathological cascade leading to neuronal loss/cognitive impairment. Targeting neuroinflammatory mediators with IMiDs represent a promising AD therapeutic strategy.

“A.B.C.” of Immunotherapy in Hematological Malignancies…Promise and Perils

AbstractThe treatment landscape of hematological malignancies has been evolving at an extremely fast pace. Hematological malignancies are diverse and distinct from solid tumors. These constitute challenges, which are also unique opportunities for immunotherapy. The five categories of immunotherapies that have found success in the management of hematological malignancies are allogeneic hematopoietic stem cell transplant, monoclonal antibodies and innovative designs, immune checkpoint inhibitors, chimeric antigen receptor (CAR) T cells, and B cell targeting small immunomodulatory molecules. Allogeneic stem cell transplant rightly called our bluntest weapon is the oldest form of successful immunotherapy. Alternate donor transplants and improvement in supportive care have improved the scope of this immunotherapy option. Among monoclonal antibodies, rituximab forms the prototype on which over a dozen other antibodies have been developed. The bispecific T-cell engager (BiTE) blinatumomab engages cytotoxic CD3 T cells with CD19 acute lymphoblastic leukemia (ALL) cells, which is an effective treatment method for relapsed refractory ALL. Immune checkpoint inhibitors have established their role in hematological malignancies with high PD-L1 expression, including relapsed refractory Hodgkin's lymphoma and primary mediastinal B cell lymphoma (BCL). Small immunomodulatory drugs targeting the B cell receptor downstream signaling through BTK inhibitors, SYK inhibitors, PI3K inhibitors (idelalisib), and BCL-2 inhibitors (venetoclax), and immunomodulatory imide drugs (lenalidomide) have also emerged as exciting therapeutic avenues in immunotherapy. CAR T cells are one of the most exciting and promising forms of adoptive immunotherapy. CAR T cells are rightly called living drugs or serial killers to keep patients alive. CAR T cells are genetically engineered, autologous T cells that combine the cytotoxicity of T cells with the antigen-binding specificity of CARs. CARs are antigen-specific but major histocompatibility complex/human leukocyte antigen-independent. There are five approved CAR T cell products for the management of relapsed refractory leukemias, lymphoma, and multiple myeloma. The past and present of immunotherapy have been really exciting and the future looks incredibly promising. The challenges include widening the availability and affordability beyond specialized centers, identification of potentially predictive biomarkers of response, and experience in the management of complications of these novel agents. The combinational approach of multiple immunotherapies might be the way forward to complement the treatment strategies to harness the immune system and to improve survival with good quality of life.

IMiDs Synergize with EP300 Inhibition to Disrupt the Ikzf/MYC/IRF4 Axis in Multiple Myeloma

Multiple myeloma (MM) is a heterogeneous plasma cell malignancy for which current therapies eventually fail. In myeloma, endogenous and translocated superenhancers drive the expression of the lineage-defining transcription factor IRF4 and oncogene MYC, respectively - both considered "undruggable". Successful standard-of-care immunomodulatory imide drugs (IMiDs) degrade superenhancer-binding pioneer factors IKAROS and AIOLOS; however, depletion of IKAROS and AIOLOS does not always correlate with a successful IMiD response, and patients treated with IMiDs ultimately relapse. We show responses to the IMiD Pomalidomide (POM) are directly correlated with downregulation of IRF4 and MYC. In IMiD-resistant cells and tumors, IRF4 and MYC downregulation could be achieved with novel coactivator-targeting drugs including the BET inhibitor JQ1 and the CBP/EP300 inhibitor GNE-781, but these were toxic and lacked a therapeutic window in vivo. We show how POM combined with GNE781 synergize and downregulate MYC and IRF4 levels, killing myeloma cells in vitro and in vivo. However, resistance to this combination was induced by expression of the AP-1 factor BATF, which directly maintained IRF4 expression and myeloma cell survival. These results identify a potent therapeutic combination and a hereto unrealized mechanism of IMiD resistance in multiple myeloma.