Immunomodulatory Drugs Lenalidomide Research Articles

Pharmacovigilance in Multiple Myeloma Care in Sub-Saharan Africa: A Review of Immunomodulatory Anti-myeloma Guidelines Using Kenyan AMPATH Framework

Background: Pharmacovigilance is a science that deals on the impact of therapeutic interventions (i.e., benefits and adverse effects) on the target body. In multiple myeloma treatment, it deals with the impact of anti-myeloma drugs on target patients through their risk assessment and risk management. This framework ensures safety and surveillance of anti-myeloma drugs administered to prospective multiple myeloma patients. Pharmacovigilance of anti-myeloma therapy is rarely instituted in the health institutions in sub-Saharan Africa due to late diagnosis and poor palliative care system in the region. The hallmarks are increased disability adjusted life-years, reduced quality adjusted life-years and average survival interval of people living with multiple myeloma in the region.
 Aim: This study highlighted the safety measures undertaken by the healthcare professionals and multiple myeloma patients who are on immunomodulatory (Thalidomide and Lenalidomide) anti myeloma drugs to prevent or minimize adverse drug reactions.
 Methodology: This study was a review of the guidelines for Pharmacovigilance using Kenyan AMPATH anti-myeloma pharmacovigilance brochures and other research database as literature sources. The paper was analysed and grouped according to the following categories namely the adverse drug reactions encountered with the use of anti-myeloma drugs and pharmacovigilance risk management programme (RMP) for immunomodulatory drugs (thalidomide and lenalidomide).
 Results: The three major identified safety tools for effective pharmacovigilance of the anti-myeloma patient population were the healthcare professional workforce, safety guidelines brochures and safety forms for registration and documentation of impact of therapeutic interventions. The healthcare professionals are key players in the formulation of pharmacovigilance risk management protocols. The risk management starts with education of the healthcare providers and myeloma patients using guidelines brochures designated for the respective groups. The prescriber registration-, pharmacy registration-, treatment initiation-, prescription authentication-, and adverse drug reaction forms are the essential safety working documents that are needed to be completed by the patient and healthcare professionals for effective monitoring and evaluation. Both the healthcare provider and the myeloma patient are expected to adhere strictly to the safety measures enshrined in the pharmacovigilance guideline brochures. The patient’s anti-myeloma safety measures are stratified into female of child bearing age, women above the child-bearing age and the male sub-population.
 Conclusion: In setting up a comprehensive multiple myeloma care centre, an effective pharmacovigilance program is paramount. This requires healthcare professional workforce, safety guidelines brochures and safety forms for registration and documentation of impact of therapeutic interventions. Policy formulation, sustainable drug availability and collaboration with support groups are vital tools to drive this operative framework in underserved settings of sub-Saharan Africa.

PB2112: MINDWAY: A PHASE IB/II DOSE OPTIMIZATION STUDY TO ASSESS SAFETY AND PHARMACOKINETICS OF TAFASITAMAB + LENALIDOMIDE IN PATIENTS WITH RELAPSED/REFRACTORY DIFFUSE LARGE B-CELL LYMPHOMA

Background: Tafasitamab is an Fc-enhanced, humanized, anti-CD19 monoclonal antibody which, in combination with the immunomodulatory drug lenalidomide, has been granted accelerated FDA approval and EU conditional marketing authorization based on results from L-MIND (NCT02399085) for the treatment of relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) in adult patients ineligible for autologous stem cell transplant. Treatment schedule optimization aims to reduce the frequency of hospital visits and decrease treatment burden and healthcare utilization while maintaining clinical benefits. Aims: MINDway (NCT05222555) will investigate if administration of tafasitamab at levels higher than the approved 12 mg/kg dose at a reduced dosing frequency can maintain the benefit-risk relationship of tafasitamab + lenalidomide treatment for patients with R/R DLBCL. Methods: MINDway is an open-label, multicenter, Phase Ib/II study in patients aged 18‒80 years with histologically confirmed DLBCL and R/R status after at least one, but no more than three, prior systemic regimens, including CD20-targeted therapy. Patients previously treated with CD19-targeted therapy or with immunomodulatory imide drugs such as lenalidomide are excluded. The modified tafasitamab dosing regimen will be investigated in a stepwise design with two sequential dose-finding cohorts (planned n=6 each) followed by an expansion cohort (planned n=39; Figure). Lenalidomide 25 mg will be administered in all cohorts on Day (D) 1‒21 of each 28-D cycle for up to 12 cycles. After Cycle 12, patients will continue tafasitamab monotherapy at the assigned dosing regimen until progression. Following a review of the safety and pharmacokinetic data from Cohorts 1 and 2, patients will be enrolled in an expansion cohort to receive tafasitamab + lenalidomide at the tafasitamab dose of 24 mg/kg or 30 mg/kg for further evaluation. No intra-patient dose escalation from 24 mg/kg to 30 mg/kg is permitted. The primary endpoint is the incidence and severity of treatment-emergent adverse events; key secondary endpoints include tafasitamab serum concentrations after 3 and 12 treatment cycles and best objective response rate, duration of response, and progression-free survival by investigator assessment. All endpoints will be analyzed using descriptive statistics; no formal statistical tests will be performed. MINDway is currently enrolling, with a planned sample size of 51 patients. Results: Results for this study are not yet available: outcome data as described above will be presented in due course. Image:Summary/Conclusion: MINDway will optimize the tafasitamab dosing regimen to reduce the frequency of hospital/clinic visits for tafasitamab treated R/R DLBCL patients. Reducing the overall frequency of clinic visits by half is expected to reduce the patient burden and support long-term treatment compliance. Furthermore, given the severity of the disease, reduced hospital visits may result in less exposure to hospital infections in this already susceptible population.

Abstract 2981: Loss of the small GTPase RHOA enhances lymphomagenesis and impairs the activity of lenalidomide in mantle cell lymphoma

Abstract The small GTPase Ras homolog family member A (RHOA) is one of the most extensively investigated members of the Rho GTPase family, that acts as a molecular switch controlling a wide variety of signal transduction pathways. Although RHOA has long been implicated in malignant transformation in solid tumors, recent evidences have demonstrated its tumor suppressor activity in different subgroups of B-cell non-Hodgkin lymphoma (B-NHL). Here, using a panel of 11 cell lines covering the most common and/or aggressive B-NHL subtypes, we observed that the lowest mRNA and protein levels of RHOA are found in mantle cell lymphoma (MCL), the most aggressive entity with a median overall survival of 5-7 years. Depletion of RHOA expression and activity was carried out in the two RHOA+ MCL cell lines, REC-1 and Z-138, by CRISPR/Cas9-mediated gene edition followed by RHOA pulldown activation assay. In RHOA knockout (KO) subclones, cell proliferation was increased by 40%, in association with a 10-fold increase in mitotic index and a 3-fold potentiation of cell migration, as assessed respectively by CellTitter-Glo assay, histone H3-pSer10 labeling and Transwell assay, thus suggesting a tumor suppressor role of RHOA in MCL malignancy. Comparative RNA-seq analysis of RHOAWT and RHOAKO MCL subclones then highlighted a crucial role of RHOA and its downstream signaling in the control of MCL cell proliferation, cell cycle and cell migration. Interestingly, the immunomodulatory drug lenalidomide has previously shown to regulate such processes and to be clinically active in patients with relapsed/refractory MCL. In a co-culture system associating RHOAWT MCL cells with peripheral blood-derived effector cells, we observed that lenalidomide treatment facilitated the formation of immunological synapse, as revealed by simultaneous immunodetection of effector T cells, target B cells and perforin, and by quantification of lactate dehydrogenase (LDH) release. Conversely, lenalidomide exhibited minimal effect in the RHOAKO MCL co-cultures, as shown by a 30-40% decrease in the formation of immune synapse and a 4-fold decrease in LDH secretion. Taken together, these data provide the first insight into the tumor suppressive activity of RHOA in MCL and into its requirement for the immune-mediated mechanism of action of lenalidomide in this disease. Ongoing in vivo validation studies will be presented. Citation Format: Juliana C. Santos, Marcelo L. Ribeiro, Gael Roue. Loss of the small GTPase RHOA enhances lymphomagenesis and impairs the activity of lenalidomide in mantle cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2981.

A multi-step continuous flow synthesis of pomalidomide

The immunomodulatory drugs (IMiDs) thalidomide, pomalidomide, and lenalidomide are widely used to treat multiple myeloma. The permanent need of IMiDs analogues in clinical screening and practice has created the demand to find a reliable and robust method for their preparation. To reach this goal, the use of flow chemistry is quite appealing, allowing a safe operation, an excellent reproducibility and an efficient process. Herein, we describe a continuous 3–4 step flow approach for the synthesis of the pomalidomide (38–47% overall yield) and a few analogues.Graphical abstract

Proteomic profiling reveals CDK6 upregulation as a targetable resistance mechanism for lenalidomide in multiple myeloma

The immunomodulatory drugs (IMiDs) lenalidomide and pomalidomide are highly effective treatments for multiple myeloma. However, virtually all patients eventually relapse due to acquired drug resistance with resistance-causing genetic alterations being found only in a small subset of cases. To identify non-genetic mechanisms of drug resistance, we here perform integrated global quantitative tandem mass tag (TMT)-based proteomic and phosphoproteomic analyses and RNA sequencing in five paired pre-treatment and relapse samples from multiple myeloma patients. These analyses reveal a CDK6-governed protein resistance signature that includes myeloma high-risk factors such as TRIP13 and RRM1. Overexpression of CDK6 in multiple myeloma cell lines reduces sensitivity to IMiDs while CDK6 inhibition by palbociclib or CDK6 degradation by proteolysis targeting chimeras (PROTACs) is highly synergistic with IMiDs in vitro and in vivo. This work identifies CDK6 upregulation as a druggable target in IMiD-resistant multiple myeloma and highlights the use of proteomic studies to uncover non-genetic resistance mechanisms in cancer.

Lenalidomide in cancer cachexia: a randomized trial of an anticancer drug applied for anti‐cachexia

AbstractBackgroundCancer cachexia (CC) impacts quality of life, physical function, anticancer treatment response, and survival. Inflammation is a prominent pathomechanism of CC. This small‐scale study sets out to investigate the immunomodulatory drug lenalidomide in inflammatory CC in a randomized, double‐blind, placebo‐controlled trial.MethodsPatients with advanced solid malignancies, documented weight loss, no or unchanged anticancer treatment, and C‐reactive protein > 30 mg/L were included. In a 2:2:1 randomization, patients received either lenalidomide 25 mg once daily or C‐reactive protein‐guided dose, starting with 5 mg lenalidomide once daily or placebo once a day for 8 weeks. Dose adaption and safety were assessed twice a week. Treatment response was defined as an increase of lean body mass of more than 2% in a lower lumbar computed tomography and an increase in dynamometer‐assessed handgrip strength of 4 kg. Secondary endpoints included adverse events, C‐reactive protein response, nutritional intake, and symptoms.ResultsOf 24 eligible patients, 16 were included (25% female). At baseline, the mean age was 67 (range 51–88) years, and mean body weight was 64.7 kg (range 39.8–87.2 kg). Five were diagnosed with mesothelioma, two with non‐small‐cell lung cancer, two with renal cell carcinoma, two with neuroendocrine tumours, and five with other malignancies. Mean survival was 43 days. Eleven adverse events (four of which were severe) were recorded with a probable link to study participation. Nine patients completed the study. No participant showed a treatment response. C‐reactive protein‐guided dosing did not result in lower doses of lenalidomide. Lean body mass decreased less in the treatment groups. For the lenalidomide and placebo groups respectively, handgrip strength decreased by 2.3 vs. 5.5 kg, nutritional intake decreased by 249 vs. 32 kcal/day, and C‐reactive protein increased by 35 mg/dL vs. decreased by 17 mg/dL. The study was closed prematurely due to slow accrual and the need for concurrent anticancer treatments.ConclusionsNo treatment response on muscle mass and muscle strength was observed with lenalidomide. Because of several limiting factors, including low recruitment caused in part by an ambitious study design and concomitant anticancer treatment, this study did not generate adequate data to draw reliable conclusions.

Follicular lymphoma: is more better or is less really more?

In The Lancet Haematology, Catherine Diefenbach and colleagues1 report results of a phase 1b/2 study evaluating the CD79b-directed antibody–drug conjugate polatuzumab vedotin in combination with the anti-CD20 antibody obinutuzumab and the immunomodulatory drug lenalidomide in a cohort of patients with relapsed or refractory follicular lymphoma.1

Abstract 10860: Cardiotoxicity as an Adverse Effect of Immunomodulatory Drugs and Proteasome Inhibitors in Multiple Myeloma: A Meta-Analysis of Randomized Clinical Trials

Introduction: Combination therapy of Immunomodulatory drugs (iMiDs) (Thalidomide, Lenalidomide, Pomalidomide) and Proteasome Inhibitors (PIs) (Bortezomib, Carfilzomib, Ixazomib) constitutes the backbone of treatment in MM patients. Cardiotoxic side-effect profile of iMiDs is not well-documented. Although Carfilzomib has been associated with cardiotoxicity, whether its adverse effects also mirror the class-specific cardiotoxic profile of PI remain obscure. Proper assessment of cardiotoxicity due to treatment reagents is necessary for optimal patient management. In this pairwise meta-analysis, we explored direct cardiotoxicity with iMiDs and PIs use in patients with multiple myeloma (MM). Hypothesis: Treatment with iMiDs and PIs in MM patients leads to independent cardiotoxicity that is associated with individual class of drugs. Methods: Published randomized control trials (RCTs) were searched up to May 2021 reporting cardiotoxicity (cumulative reported events of ischemia, arrhythmia, failure, stenosis) in MM patients (newly diagnoses and/or relapsed) treated with iMiD and/or PI. Studies, where iMiD or PI were used atop the chemotherapy vs placebo or no additional drugs (control) in the other arm, were included. The primary outcome was presence of cardiotoxicity after follow-up. Meta-analysis was performed using frequentist’s approach to estimate odds ratio (OR). Results: Eighteen RCTs including 8,479 MM patients were included in this analysis. Eleven studies compared iMiDs and seven studies compared PIs with control. CTACE high-grade (≥ grade 3) cardiotoxic events were increased with iMiDs in comparison to their control counterpart (OR 2.05; 95% CI 1.30-3.26). Cardiotoxicity was also noted more frequently with PI use when compared to the control group (OR 1.47; 95% CI 1.19-1.82). Similar difference was observed between high-grade cardiotoxic complication between these groups. There was no evidence of publication bias among studies. Conclusions: Our results showed iMiDs and PIs are independently associated with cardiotoxicity, which may warrant increased awareness among treating physicians and close monitoring of patients. The adverse cardiac event profile with these drugs require further investigation in future studies.

Results from a Pilot Study of ARI0002h, an Academic BCMA-Directed CAR-T Cell Therapy with Fractionated Initial Infusion and Booster Dose in Patients with Relapsed and/or Refractory Multiple Myeloma

Results from a Pilot Study of ARI0002h, an Academic BCMA-Directed CAR-T Cell Therapy with Fractionated Initial Infusion and Booster Dose in Patients with Relapsed and/or Refractory Multiple Myeloma

Potent Ikaros Degradation By the Cereblon E3 Ligase Modulator CC-92480 Is Effective in Combination with Menin-MLL1 Inhibition in MLL1-Rearranged and NPM1-Mutant AML

Potent Ikaros Degradation By the Cereblon E3 Ligase Modulator CC-92480 Is Effective in Combination with Menin-MLL1 Inhibition in MLL1-Rearranged and NPM1-Mutant AML

Physicochemistry of Cereblon Modulating Drugs Determines Pharmacokinetics and Disposition.

Immunomodulatory drugs (IMiDs) thalidomide, lenalidomide, and pomalidomide engage cereblon and mediate a protein interface with neosubstrates such as zinc finger transcription factors promoting their polyubiquitination and degradation. The IMiDs have garnered considerable excitement in drug discovery, leading to exploration of targeted protein degradation strategies. Although the molecular modes-of-action of the IMiDs and related degraders have been the subject of intense research, their pharmacokinetics and disposition have been relatively understudied. Here, we assess the effects of physicochemistry of the IMiDs, the phthalimide EM-12, and the candidate drug CC-220 (iberdomide) on lipophilicity, solubility, metabolism, permeability, intracellular bioavailability, and cell-based potency. The insights yielded in this study will enable the rational property-based design and development of targeted protein degraders in the future.

Management of Myelofibrosis-Associated Anemia: Focus on Standard Agents and Novel Therapeutics in Phase 3 Clinical Trials.

The management of myelofibrosis is risk-adapted when considering transplant eligibility and symptom-directed, prioritizing the most burdensome symptoms for the patient. Unfortunately, myelofibrosis-anemia is common, multifactorial in its origin, and impactful regarding prognosis. While clinical trials are advised, not all patients have convenient access, and therefore, hematologists should be aware of the data supporting the use of conventional agents such as erythropoietin-stimulating agents, steroid treatments (danazol and prednisone), and immunomodulatory drugs (thalidomide and lenalidomide). This review summarizes the conventional approach to treating myelofibrosis-anemia and highlights recent data from 3 novel agents that are under phase 3 evaluation. Momelotonib is a JAK1/2 and ACVR1 inhibitor that has demonstrated not only improvements in splenomegaly and symptoms, but also amelioration of anemia on the SIMPLIFY 1 and 2 clinical trial program. This may occur through suppression of hepcidin production. Luspatercept promotes late-stage hematopoiesis, and the phase 2 study has shown promise in ameliorating anemia as a monotherapy, and especially in combination with ruxolitinib. Finally, CP-0160, a BET inhibitor, has shown efficacy as an anemia-directed agent, when used as monotherapy and in combination. This agent reduces cytokine production and promotes erythroid differentiation. Results have been presented for patients previously treated with JAK inhibitors, as well as those who were naïve to JAK inhibitor therapy. Safety and effectiveness are reviewed for both conventional and selected novel agents used in the treatment of MF-anemia. A practical approach to treatment is presented, and data from ASH 2020 are presented.

Targeting intracellular WT1 in AML with a novel RMF-peptide-MHC-specific T-cell bispecific antibody

AbstractAntibody-based immunotherapy is a promising strategy for targeting chemoresistant leukemic cells. However, classical antibody-based approaches are restricted to targeting lineage-specific cell surface antigens. By targeting intracellular antigens, a large number of other leukemia-associated targets would become accessible. In this study, we evaluated a novel T-cell bispecific (TCB) antibody, generated by using CrossMAb and knob-into-holes technology, containing a bivalent T-cell receptor–like binding domain that recognizes the RMFPNAPYL peptide derived from the intracellular tumor antigen Wilms tumor protein (WT1) in the context of HLA-A*02. Binding to CD3ε recruits T cells irrespective of their T-cell receptor specificity. WT1-TCB elicited antibody-mediated T-cell cytotoxicity against AML cell lines in a WT1- and HLA-restricted manner. Specific lysis of primary acute myeloid leukemia (AML) cells was mediated in ex vivo long-term cocultures by using allogeneic (mean ± standard error of the mean [SEM] specific lysis, 67 ± 6% after 13-14 days; n = 18) or autologous, patient-derived T cells (mean ± SEM specific lysis, 54 ± 12% after 11-14 days; n = 8). WT1-TCB–treated T cells exhibited higher cytotoxicity against primary AML cells than an HLA-A*02 RMF-specific T-cell clone. Combining WT1-TCB with the immunomodulatory drug lenalidomide further enhanced antibody-mediated T-cell cytotoxicity against primary AML cells (mean ± SEM specific lysis on days 3-4, 45.4 ± 9.0% vs 70.8 ± 8.3%; P = .015; n = 9-10). In vivo, WT1-TCB–treated humanized mice bearing SKM-1 tumors exhibited a significant and dose-dependent reduction in tumor growth. In summary, we show that WT1-TCB facilitates potent in vitro, ex vivo, and in vivo killing of AML cell lines and primary AML cells; these results led to the initiation of a phase 1 trial in patients with relapsed/refractory AML (#NCT04580121).

Protein Kinase CSNK1A Regulates the Multiple Myeloma Plasma Cell-Microenvironment Interplay

Multiple myeloma (MM) is a plasma cell malignancy characterized by a strong dependency on the bone marrow microenvironment, which makes plasma cells resistant to pro-apoptotic stimuli and favours the myeloma-associated bone disease (MMABD). Alteration of Wnt/β-catenin, Hedgehog (Hh) and NF-κB signaling by plasma cell-intrinsic or bone marrow stroma-delivered signals sustains MM cell growth and contributes to bone homeostasis alterations. Protein kinase CK1α (CSNK1A1, casein kinase 1α) belongs to a family of monomeric Ser/Thr kinases that regulate cellular processes important in cancer biology such as membrane biogenesis, transport of molecules, signal transduction, transcription, translation and the DNA damage response. CK1α is also an essential regulator of the function of the Wnt, Hh and NF-κB signalling pathways. It is known that osteogenic differentiation is dependent on the activation of Wnt/β-catenin and that CK1α exerts a negative regulative role on this pathway. Thus, CK1α could play a role in MMABD representing a rational therapeutic target. We recently demonstrated that CK1α supports MM plasma cells growth, in part through the regulation of AKT and β-catenin. CK1α is overexpressed in MM patients compared to healthy controls, and its inhibition/silencing in plasma cells causes apoptosis and cell cycle arrest (Manni et al ., 2017, Oncotarget 8(9):14604). To investigate if this kinase could regulate osteogenesis, we analyzed the generation of osteocytes from stromal cells in conditions of CK1α inactivation in BM stromal cells (BMSC). We found that at variance from malignant plasma cells, CK1α silencing in bone marrow stromal cells did not impact on cell survival but it enhanced the differentiation potential towards bone formation, inducing an osteoblastogenic transcriptional program. CK1α silencing in BMSC, led to the stabilization of β-catenin, increased mRNA expression of the osteoblast markers RUNX2, SPP1 and BGLAP, and it increased calcium deposits of stromal cells pushed to differentiate towards osteoblasts/osteocytes. Moreover, we observed that the immunomodulatory drug lenalidomide, by inducing CK1α degradation in both MM and stromal cells, potentiated the effects of CK1α silencing in BMSC, further supporting osteoblast formation. Previous papers reported that MM cells overexpress RUNX2, leading to a higher expression of RANKL, which in turn could be responsible of the inhibition of osteoblast activity in the bone marrow microenvironment (Giuliani et al., 2005 ; Blood 106, 2472). Moreover, elevated expression of RUNX2 in MM cells enhanced tumour growth and bone disease (Trotter et al., 2015, Blood 125, 3598). To investigate the effects of CK1α on RUNX2 levels in MM cells, we created a model whereby the BM microenvironment dependent INA-6 cell lines were stably transduced with lentiviral shRNA vectors to obtain CK1α silencing by addition of IPTG and then were cultured in the presence of BM stromal cells. At variance with BMSC, CK1α silencing in MM cells determined a reduction of RUNX2 in MM cells with a consequent RANKL-induced increase of RUNX2 in stromal cells. Therefore, CK1α could have a positive regulative role on RUNX2 expression in MM cells participating in the impairment of osteoblastogenesis and yet a negative regulative role still on RUNX2 levels in BMSC. Altogether, our data provide a mechanistic framework for the function of CK1α in BMSC biology and in the MM-BMSC crosstalk and support a dual beneficial therapeutic role of CK1α inhibition in MM, with the potential of targeting not only the malignant plasma cells but also the MMABD. DisclosuresNo relevant conflicts of interest to declare.

Daratumumab, Lenalidomide, and Dexamethasone (DRd) Versus Lenalidomide and Dexamethasone (Rd) in Relapsed or Refractory Multiple Myeloma (RRMM) Based on Prior Treatment History, Renal Function, and Cytogenetic Risk: Subgroup Analyses of Pollux

Daratumumab, Lenalidomide, and Dexamethasone (DRd) Versus Lenalidomide and Dexamethasone (Rd) in Relapsed or Refractory Multiple Myeloma (RRMM) Based on Prior Treatment History, Renal Function, and Cytogenetic Risk: Subgroup Analyses of Pollux

Clonal Evolution in Newly Diagnosed Multiple Myeloma Patients: A Follow-up Study from the Mmrf Commpass Genomics Project

Multiple Myeloma (MM) is an incurable malignancy of bone marrow plasma cells characterized by wide molecular diversity and complex clonal and subclonal architecture. Intra-tumor heterogeneity reflects the evolution of the disease. Clonal structure may affect response to treatment, which, in turn, may shape tumor evolution and, consequently, contribute to drug resistance. Thus, analysis of tumor clonality has profound implications for personalized medicine.Using our recently developed network model of newly diagnosed MM from the MMRF CoMMpass study (Lagana et al, Leukemia 2017) , MMNet, we have identified patterns of gene co-expression significantly associated with tumor clonality and showed that clonality is correlated with mutational burden and relapse.In order to characterize the evolution of clonal structure from diagnosis to relapse, we analyzed Whole-Exome data (WES) from 19 patients enrolled in CoMMpass for whom sequencing data for multiple time points was available. The cohort included both male (12; 63%) and female (7; 37%) patients of white/caucasian (14; 73%) and black/african-american (5; 27%) origin. Patients were distributed among five of the ten classes defined by MMNet: CCND1 (4; 21%), MAF (1; 5%), MMSET (2; 10%), HY/NRAS (4; 21%), and IMM (4; 21%) (4 were unassigned). Also, six patients had the t(11;14) and two had the t(4;14) chromosomal translocations. All patients had received induction therapy, consisting of combinations of proteasome inhibitors (PI) (Bortezomib: 19, 100%; Carfilzomib: 3, 16%), immunomodulatory drugs (IMiDs) (Lenalidomide: 13, 68%; Pomalidomide: 2, 10%; Thalidomide: 1, 5%), steroids (18, 95%) and monoclonal antibodies (Daratumumab: 1, 5%). Best responses to therapy were CR/sCR (3; 16%), VGPR (7; 37%) and PR (9; 47%). Fourteen (68%) patients had SD or PD at the second sequencing time point, with a median PFS of 456 days.Our analysis inferred subclonal tumor composition and evolution based on somatic mutations and copy number alterations (CNA) using PhyloWGS (Deshwar et al, Genome Biol 2015). Patients had one (14; 74%), two (4; 21%) or three (1; 5%) founding clones at baseline, and numerous subclones. Trajectories of cancer cell populations revealed dramatic changes in most patients in terms of clonal and subclonal cell fractions between baseline and relapse. In most patients we observed emergence of new competing clones at relapse, where one or more subclones decreasing in size were replaced by other subclones, indicating selective pressure introduced by therapy (Fig. 1).Subclones were characterized in terms of mutations and CNA and were labeled as stable/resistant or sensitive based on their trajectories from baseline to relapse. Our analysis revealed significant inter-patient heterogeneity in terms of mutations and clonal composition, with few overlaps. We identified subclonal drivers by screening the observed mutations and CNA against a database of known cancer drivers and analysis of co-occurrence and mutual exclusivity. Our analysis revealed that stable/resistant clones were characterized by concurrent deletion of 17p and 13q, and/or mutations in NRAS. In particular, 7 out of 19 patients had at least one mutation in NRAS, observed at baseline in 5 cases, and with two patients carrying two different mutations in two different clones. Our findings support earlier adoption of targeted therapy against RAS (e.g. Trametinib). Other drivers found exclusively in resistant clones included DIS3, FAM46C, ROBO1 and CCND1.Overall, our analysis provides genomics characterization of relapsed patients in CoMMpass following induction therapy, reveals heterogeneous clonal and subclonal composition and trajectories from baseline to relapse, and defines specific somatic mutations (e.g. NRAS) and CNA as drivers of resistance to induction therapy. [Display omitted] DisclosuresMadduri:Foundation Medicine, Inc.: Consultancy. Chari:Janssen: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Millennium Pharmaceuticals, Inc.: Consultancy, Research Funding; Amgen: Honoraria, Research Funding; Celgene Corporation: Consultancy, Research Funding. Cho:Bristol Myers-Squibb: Other: advisory board, Research Funding; Agenus, Inc.: Research Funding; Genentech: Other: advisory board, Research Funding; Ludwig Institute for Cancer Research: Research Funding; Multiple Myeloma Research Foundation: Research Funding. Barlogie:Millenium Pharmaceuticals: Consultancy, Research Funding; Celgene Corporation: Consultancy, Research Funding. Jagannath:Celgene: Consultancy; Bristol-Meyers Squibb: Consultancy; Merck: Consultancy; Medicom: Speakers Bureau; MMRF: Speakers Bureau; Novartis: Consultancy. Dudley:GlaxoSmithKline: Consultancy; Janssen Pharmaceuticals, Inc.: Consultancy; Ayasdi, Inc.: Equity Ownership; Ecoeos, Inc.: Equity Ownership; NuMedii, Inc.: Equity Ownership, Patents & Royalties; Ontomics, Inc.: Equity Ownership; Personalis: Patents & Royalties; AstraZeneca: Consultancy.

Protein Homeostatic Modulators, a Novel Class of Cereblon-Targeting Small Molecules As Potential Clinical Candidates in Multiple Myeloma

BackgroundThe immunomodulatory drugs (IMiDs) Thalidomide (THAL), Lenalidomide (LEN), and Pomalidomide (POM) have demonstrated potent anti-multiple myeloma (MM) activity both pre-clinically and clinically, and are accepted standards of care. LEN, POM and recently discovered analogs bind cereblon (CRBN), an E3 ubiquitin ligase, which confers gain-of-function recruitment of a specific set of target substrates, resulting in their proteasomal degradation with subsequent anti-proliferative and immunomodulatory effects. Although the list is likely incomplete, several cereblon-targeted substrates have been identified, including Ikaros (IK1), Aiolos (IK3), CK1a, and GSPT1. The specific subset of targeted substrates, and their respective extent and rate of degradation, determine the compound's net therapeutic benefit. In this study, we found activity in MM and related hematologic malignancies from a novel series of cereblon-binding small molecules known as Protein Homeostatic Modulators™ (PHMs™).ResultsSimilar to the clinical IMiDs (THAL, LEN, and POM), the novel class of small molecules PHMs™ targets CRBN, acting as a molecule “glue” that promotes ubiquitination and subsequent proteosomal degradation of known select substrates such as CK1a, Ikaros, and GSPT1; and potentially, yet to be identified new clinically relevant substrates. In this study, we showed that while some PHMs have similar phenotypic and substrate degradation activity profiles to the clinical IMiDs, there are clear divergent profiles that are emerging. These activity profiles are derived from a multidimensional set of results such as cancer cell proliferation; cytokine and chemokine regulation; cellular differentiation; and specific substrate degradation. Using these profiles, we have identified potential clinical candidates for cancer and immune dysfunction. BTX252, BTX293 or BTX299 displayed the ability to promote degradation of GSPT1, Ikaros and CK1a. BTX304 is more potent in inhibiting IL-6 or TNFa in LPS stimulated PBMCs and degrading Ikaros than POM. The calculated IC50 for BTX306 is 0.0028 uM. BTX306-induced degradation of GSPT1 correlates well with its observed anti-proliferative activity. To identify potential PHM™ candidates for the treatment of relapsed and refractory MM, lead PHMs were tested on LEN resistant MM cell lines. To further understand and identify the clinical utility of the unique activity profiles of the various classes of PHMs, combination treatment of myeloma cell lines as well as drug resistant myeloma cell lines using standard-of-care chemotherapy (including the clinical IMiDs) will be presented.ConclusionWe have shown that the PHMs, a novel class of CRBN-binding small molecules, have both similar activity profiles (phenotypic and substrate degradation) to the clinical IMiDs (LEN and POM) as well as unique activity profiles that are divergent to the clinical IMiDs. The lead PHMs, BTX306 and BTX304 have potential as a therapeutic agent in the treatment of MM and other hematological malignancies.MethodsPhenotypic Screening of PHMTM Library. (A) Proliferation. The anti-proliferative activity of BTX136, BTX161, BTX185, BTX196, BTX200, or BTX226 was examined in KAS6 cells. DMSO, LEN and POM were included as controls. (B) Apoptosis. Examine the level of apoptosis in ANBL6 cells in response to treatment with BTX136, BTX161, BTX185, BTX196, BTX200, or BTX226 using flow cytometric assay. DMSO, LEN and POM were included as controls. (C) Target Substrate Profile. Western Blot analysis of a dose-response from Jurkat cells treated with DMSO, BTX252, BTX293 or BTX299 for 6 hrs. (D) Immune Modulation. The level of TNFa was measured in human primary PBMCs stimulated with LPS (100 ng/mL) for 18 hrs after dosing with Controls (DMSO or LPS only), POM or the indicated PHMTM.Lead Cytotoxic PHMTM. (A) Cell proliferation assay of Molm-13 cells treated with BTX306 for 3 days. (B) Western Blot analysis of Molm-13 cells treated with a dose-response of BTX306 for 6 hrs.Lead Immunomodulatory PHMTM. (A) Target Substrate Profile. Western Blot analysis of a dose-response from Jurkat cells treated with DMSO or BTX304 for 6 hrs. (B) The level of TNFa or IL-6 expression was measured in human primary PBMCs stimulated with LPS (100 ng/mL) for 18 hrs after dosing with Controls (DMSO or LPS only), POM or BTX304. [Display omitted] DisclosuresZou:BioTheryX: Research Funding. Jones:BioTheryX: Research Funding. Sullivan:BioTheryX: Consultancy, Equity Ownership. Fung:BioTheryX: Consultancy, Equity Ownership. Richard:BioTheryX: Consultancy, Equity Ownership. Erdman:BioTheryX: Consultancy, Equity Ownership. Torres:BioTheryX: Consultancy, Equity Ownership. Chourasia:BioTheryX: Employment, Equity Ownership. Chan:BioTheryX: Employment, Equity Ownership. Mercurio:BioTheryX: Employment, Equity Ownership. Stirling:BioTheryX: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Orlowski:BioTheryX: Consultancy, Membership on an entity's Board of Directors or advisory committees.

The Role of Maintenance Therapy in Patients with Diffuse Large B-Cell Lymphoma: A Systematic Review and Meta-Analysis

Background:Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma. Although R-CHOP is nowadays considered the standard of care for DLBCL, there are still approximately 40% of patients with refractory disease or relapse, especially in the first two years. For these patients aggressive strategies as stem-cell transplantation is an option. Yet, this approach is not feasible for all patients.Our study's aim was to examine the efficacy and safety of maintenance therapy compared to observation in patients with DLBCL after achieving complete (CR) or partial response (PR) following induction therapy.Methods:Systematic review and meta-analysis of randomized controlled trials including patients with DLBCL who achieved CR or PR after first line treatment with chemotherapy +/- rituximab and comparing maintenance therapy with observation or placebo. The Cochrane Library, MEDLINE, conference proceedings and references were searched until June 2017. Two reviewers appraised the quality of trials and extracted data. Primary outcome was overall survival (OS). Secondary outcomes included all-cause mortality at 1 year, relapse rate, disease control (which include progression-free survival, event-free survival, and disease-free survival) and safety.For each trial, results were expressed as relative risks (RR) with 95% confidence intervals (CI) for dichotomous data and hazard ratios (HRs) and variances for time-to-event outcomes. We assessed heterogeneity using the I2 measure of inconsistency. Statistically significant heterogeneity was defined as p-value < 0.1 or I2 > 50%. We conducted the meta-analysis using a fixed-effect model, which assumes a similar effect measure between studies and is appropriate when no significant clinical and statistical heterogeneity is present. Random-effects model was used in analyses with significant heterogeneity (I2 > 50%).Results:Our search yielded 14 trials conducted between the years 1981 and 2016, including 3677 patients. In six and in two trials rituximab was added to all and to half of the patients receiving induction therapy, respectively. Median age of patients in the trials was 49 to 70 years. Nine trials included patients at any international prognostic index (IPI) while four of them included patients with intermediate-high and high risk age-adjusted IPI.Regarding maintenance therapy: seven trials included rituximab as the maintenance therapy, three included Interferon alfa as maintenance, two included immunomodulatory drugs (thalidomide and lenalidomide), one trial included cyclophosphamide and prednisone, and one included the serine threonine kinase inhibitor enzastaurin.Data from nine trials was available for analysis of OS. Maintenance treatment did not improve OS compared to observation, HR 0.98, [95% confidence interval (CI) 0.85-1.13, I2=0, 2980 patients]. Results were the same in a subgroup analysis by the type of maintenance (rituximab vs. other). Maintenance therapy did not decrease all-cause mortality at 1 year, RR 1.01 [95% CI 0.82-1.24, I2=0]. However, it decreased relapse rate, HR 0.78, [95% CI 0.65-0.93, I2=52, random effects model] and improved disease control compared to observation, HR 0.74, [95% CI 0.65-0.84, I2=51, random effects model]. Disease control was significantly improved in the subgroup of studies evaluating rituximab as maintenance, HR 0.73, [95% CI 0.59-0.90, I2=60, random effects model].Regarding safety, five trials reported serious or grade III/IV adverse events. These adverse events were significantly more common in the maintenance compared to observation, RR=1.72, [95% CI 1.26-2.33. I2=75%]. In addition, neutropenia and infections grade III/IV were significantly higher in the maintenance arm, RR=2.03 [95% CI 1.49-2.76, I2=44%] and RR=1.89 [95% CI 1.08-3.29, I2=0%] respectively.Conclusions:Maintenance therapy in patients with DLBCL achieving CR or PR after induction therapy did not change OS, yet it decreased relapse rate and improved disease control at the cost of a higher infection rate.Out data does not support routine administration of maintenance therapy in patients with DLBCL. Further research is needed to define subgroups which may benefit the most from this therapy. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Daratumumab, Bortezomib, and Dexamethasone Versus Bortezomib and Dexamethasone for Relapsed/Refractory Multiple Myeloma (RRMM) Patients: An Update of Overall Survival in Castor

Introduction: Daratumumab (D) is a human monoclonal antibody targeting CD38 that is approved as monotherapy and in combination with immunomodulatory drugs (lenalidomide or pomalidomide) or a proteasome inhibitor (bortezomib) for RRMM. The combination of D and bortezomib plus dexamethasone (DVd) was compared to Vd in CASTOR (ClinicalTrials.gov NCT02136134), a randomized, multicenter, phase 3 study in patients with RRMM. In the primary analysis, 29 deaths in DVd and 36 deaths in Vd were observed (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.47-1.26; Palumbo et al, N Engl J Med 2016;375(8):754-66). Here, we provide an updated analysis of overall survival (OS) in CASTOR.Methods: Eligible patients received ≥1 prior line of therapy and were randomly assigned to receive 8 cycles (every 3 weeks) of Vd (V 1.3 mg/m2 subcutaneously on Days 1, 4, 8, and 11; d 20 mg orally or intravenously (IV) on Days 1-2, 4-5, 8-9, and 11-12) with or without D (16 mg/kg IV once weekly in Cycles 1-3, every 3 weeks for Cycles 4-8, and every 4 weeks thereafter until disease progression). Patients who were refractory to bortezomib were ineligible. Progression-free survival (PFS) was the primary endpoint. OS was a secondary endpoint. Minimal residual disease (MRD) via next generation sequencing was assessed upon suspected complete response and at 6 and 12 months after the first dose at 3 sensitivity thresholds (10-4, 10-5, and 10-6) using the clonoSEQTM assay (Version 1.3, Adaptive Biotechnologies, Seattle, WA). A pre-specified interim analysis of OS was planned after 160 OS events had accrued.Results : 251 patients received DVd and 247 patients received Vd. The median (range) age was 64.0 (30-88) years. Patients received a median of 2 (1-10) prior therapies; 61% received prior autologous stem cell transplant, 66% received prior bortezomib (with 13% receiving >1 prior bortezomib-containing regimen), 42% received prior lenalidomide, 48% received prior proteasome inhibitor plus immunomodulatory drug, 28% were refractory to lenalidomide, and 32% were refractory to their last line of therapy. The median duration of treatment with single-agent daratumumab after receiving 8 cycles of Vd was 11.9 months.After median follow-up of 19.4 (range: 0-27.7) months, median OS has not been reached in either treatment group in the intent-to-treat (ITT) population (Figure 1A)andin patients who received 1 prior line of therapy (Figure1B). An exploratory analysis of the number of OS events and the 24-month OS rates revealed fewer deaths with DVd vs Vd in the ITT population and in subgroups based on the number of prior lines of therapy (Table). Among MRD-negative patients at the 10-5 sensitivity threshold, no OS events occurred in patients receiving DVd (n=29) versus 1 OS event being reported in the Vd arm (n=6). Among patients previously treated with bortezomib, the 24-month OS rate was 68% with DVd (n=162) vs 52% with Vd (n=164). Among patients refractory to lenalidomide, the 24-month OS rate was 62% and 47% with DVd (n=60) and Vd (n=81), respectively.Conclusions: Updated OS data and additional subgroup analyses will be presented at the meeting based on a pre-specified analysis of OS after 160 OS events. [Display omitted] DisclosuresLentzsch:British-Myers Squibb, Celgene, Janssen: Consultancy; Takeda: Speakers Bureau; Caelum BioSciences: Equity Ownership. Quach:Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria. Capra:Janssen: Speakers Bureau. Ovilla:Takeda Pharmaceutical Company: Consultancy, Honoraria. Thiyagarajah:Janssen: Employment. Amin:Janssen: Employment. Casneuf:Janssen: Employment. Sonneveld:Celgene Corporation, Amgen, Janssen, Karyopharm, PharmaMar, SkylineDx: Honoraria; Celgene Corporation, Amgen, Janssen, Karyopharm, SkylineDx, PharmaMar: Consultancy; Celgene, Amgen, Janssen, Karyopharm, Takeda: Consultancy, Honoraria, Research Funding. Schecter:Janssen: Employment. Hungria:Celgene, Roche, Takeda, Janssen, Amgen: Honoraria.

Lenalidomide, Pomalidomide and CC-220 Resistant Multiple Myeloma: Confirmation of Role of CRBN/IRF4 Axis and Identification of Multiple Disruption Mechanisms

The immunomodulatory drugs (IMiDs) thalidomide, lenalidomide and pomalidomide, play a pivotal role in the treatment of multiple myeloma (MM). However, while the majority of newly diagnosed MM patients respond to IMiD therapy, most patients eventually develop resistance.Cereblon (CRBN) expression has been associated with IMiDs resistance. Using a MM-specific targeting sequencing panel, we previously reported acquired mutations of CRBN or other genes in the CRBN E3 ligase complex or in the downstream CRBN pathway in 12% and 10% of MM patients refractory to IMiDs respectively. Likely this is an underestimate of pathway disruption in resistant disease since structural variation was not assessed. Notwithstanding it is clear that some IMIDs resistant MM cases failed to demonstrate any abnormality in the CRBN pathway.In this report, we describe the establishment of four isogenic human MM cell lines (HMCLs) respectively sensitive and resistant to lenalidomide, generated by culturing lenalidomide-responsive cell lines (MM.1S, KMS11, XG1 and OPM2) in the presence of lenalidomide for an extended time. Those cell lines were further tested for their responses to other IMiD members (pomalidomide and CC-220) and Bortezomib (as a control). All of the 4 isogenic resistant lines showed resistance to each of the IMiDs, but not to Bortezomib. To identify the underlying mechanisms for resistance, immunobotting was performed for expression of CRBN, IKZF1/3, IRF4, MYC, CD147, MCT1, CTNNB1 and ERK1/2. Three of the four resistant cell lines were identified as having a significant decrease or absence of CRBN expression compared to their isogenic IMiDs-sensitive lines. Consistently, CRBN mediated degradation of IKZF1 and IKZF3 and down-regulation of IRF4 and MYC upon lenalidomide treatment in those cells was abrogated or substantially reduced. Lenalidomide induced-CD147 and MCT1 destabilization was also inhibited in resistant cells. When wild type-CRBN was re-introduced, sensitivity to lenalidomide was completely restored, confirming that CRBN deficiency or dysfunction mediated the resistance. Genomic analysis of two resistant cell lines indicated that MM.1Sres carries both a CRBN deletion and a point mutation on the second allele, while KMS11res harbors a structural deletion of CRBN.Surprisingly one of the resistant cell lines, XG1res, still has abundant CRBN expression. Accordingly, lenalidomide induced-degradation of IKZF1 and IKZF3 in XG1res is identical to its isogenic sensitive line XG1, and the introduction of exogenous CRBN into XG1res did not restore its sensitivity to lenalidomide. In both XG1 and XG1res, a truncated IRF4 resulting from a genomic inversion is identified. This truncated IRF4 is substantially decreased upon lenalidomide treatment in XG1 but not in XG1res. In addition, CD147 expression is upregulated in XG1res. To understand if CD147 expression contributes to acquired resistance, CRISPR-cas9 technology was used to knockout endogenous CD147 . Depletion of CD147 in XG1res and three additional HMCLs (including two IMiD sensitive cell lines, MM.1S and KMS11, and one IMiD resistant cell line, RPMI8226)did not impact survival nor did it restore (or change) lenalidomide sensitivity even though CD147 depletion also induced a substantial reduction of MCT1 expression. mRNAseq was performed in isogenic XG1 and XG1res. Two genes associated with myeloma growth, IL-6 and STAT3, were identified as highly upregulated in XG1res. We confirmed by increased and highly activated STAT3 in XG1res. XG1res was then treated with lenalidomide plus either a specific STAT3 inhibitor (PB-1-102) or an IL-6 antibody. Compared with each drug as single agent, the combination of PB-1-102 and lenalidomide demonstrated the highest anti-myeloma activity in XG1res on MTT assay and the most downregulated IRF4 expression on immunoblotting, suggesting that activation of STAT3 was the source of IMiDs resistance, perhaps as a consequence of its regulation of the truncated IRF4.In summary, we confirm CRBN/ IKZF/IRF4/MYC pathway deficiency or dysfunction, by mutation or deletion, as the dominant mechanism associated with acquired IMIDs resistance. We also identify a novel indirect path to resistance mediated by upregulated IL-6 and STAT3 activation with consequent impact on IRF4 expression. DisclosuresStewart:Celgene: Consultancy, Honoraria.