Proteasome inhibition and its therapeutic potential in multiple myeloma

Due to an unmet clinical need for treatment, the first in class proteasome inhibitor, bortezomib, moved from drug discovery to FDA approval in multiple myeloma in an unprecedented eight years. In the wake of this rapid approval arose a large number of questions about its mechanism of action and toxicity as well as its ultimate role in the treatment of this disease. In this article, we briefly review the preclinical and clinical development of the drug as the underpinning for a systematic review of the large number of clinical trials that are beginning to shed some light on the full therapeutic potential of bortezomib in myeloma. We conclude with our current understanding of the mechanism of action of this agent and a discussion of the novel proteasome inhibitors under development, as it will be progress in these areas that will ultimately determine the true potential of proteasome inhibition in myeloma

B-cell maturation antigen (BCMA) in multiple myeloma: rationale for targeting and current therapeutic approaches.

Despite considerable advances in the treatment of multiple myeloma (MM) in the last decade, a substantial proportion of patients do not respond to current therapies or have a short duration of response. Furthermore, these treatments can have notable morbidity and are not uniformly tolerated in all patients. As there is no cure for MM, patients eventually become resistant to therapies, leading to development of relapsed/refractory MM. Therefore, an unmet need exists for MM treatments with novel mechanisms of action that can provide durable responses, evade resistance to prior therapies, and/or are better tolerated. B-cell maturation antigen (BCMA) is preferentially expressed by mature B lymphocytes, and its overexpression and activation are associated with MM in preclinical models and humans, supporting its potential utility as a therapeutic target for MM. Moreover, the use of BCMA as a biomarker for MM is supported by its prognostic value, correlation with clinical status, and its ability to be used in traditionally difficult-to-monitor patient populations. Here, we review three common treatment modalities used to target BCMA in the treatment of MM: bispecific antibody constructs, antibody-drug conjugates, and chimeric antigen receptor (CAR)-modified T-cell therapy. We provide an overview of preliminary clinical data from trials using these therapies, including the BiTE® (bispecific T-cell engager) immuno-oncology therapy AMG 420, the antibody-drug conjugate GSK2857916, and several CAR T-cell therapeutic agents including bb2121, NIH CAR-BCMA, and LCAR-B38M. Notable antimyeloma activity and high minimal residual disease negativity rates have been observed with several of these treatments. These clinical data outline the potential for BCMA-targeted therapies to improve the treatment landscape for MM. Importantly, clinical results to date suggest that these therapies may hold promise for deep and durable responses and support further investigation in earlier lines of treatment, including newly diagnosed MM

Blood Transfusion Management for Patients Treated With Anti-CD38 Monoclonal Antibodies

Daratumumab has proven to be highly efficacious for relapsed and refractory multiple myeloma (MM) and has recently been approved in the frontline setting for MM patients ineligible for transplantation. In the future, expanded indications are possible for daratumumab and other anti-CD38 monoclonal antibodies in development. For several years, it has been recognized that these therapies interfere with blood bank testing by binding to CD38 on red blood cells and causing panagglutination on the Indirect Antiglobulin Test. This can lead to redundant testing and significant delays in patient care. Given the anticipated increase in utilization of anti-CD38 monoclonal antibodies, as well as the transfusion needs of MM patients, it is critical to understand the nature of this interference with blood bank testing and to optimize clinical and laboratory procedures. In this review, we summarize the pathophysiology of this phenomenon, examine the clinical data reported to date, describe currently available methods to resolve this issue, and lastly provide a guide to clinical management of blood transfusions for patients receiving anti-CD38 monoclonal antibodies

Preferences and priorities for relapsed multiple myeloma treatments among patients and caregivers in the United States

Introduction/Background: This study aimed to describe patient and caregiver preferences for treatments of relapsed or refractory multiple myeloma (MM). Materials and Methods: A survey including discrete-choice experiment (DCE) and best-worst scaling (BWS) exercises was conducted among US patients with relapsed or refractory MM and their caregivers. The DCE included six attributes with varying levels including progression-free survival (PFS), toxicity, and mode and frequency of administration. In addition, the impact of treatment cost was assessed using a fixed-choice question. The BWS exercise included 18 items (modes and frequency of administration, additional treatment convenience, and toxicity items). The survey was administered online to patients recruited from the Multiple Myeloma Research Foundation CoMMpass study (NCT01454297). Results: The final samples consisted of 94 patients and 32 caregivers. Avoiding severe nerve damage was most important to patients, followed by longer PFS. Caregivers considered PFS to be the most important attribute. We estimate that a third or more of patients were cost-sensitive, meaning their treatment preference was altered based on cost implications. Caregivers were not cost-sensitive. The three most bothersome treatment features in the BWS exercise were risk of kidney failure, lowering white blood cell counts, and weakening the immune system. Conclusion: Patients with relapsed or refractory MM and their caregivers consider many factors including efficacy, toxicity, mode/frequency of administration, and cost in their decisions regarding treatment options. The study provides a basis for future Research on patient and caregiver treatment preferences, which could be incorporated into shared decision-making with physicians

Exposure-Response and Population Pharmacokinetic Analyses of a Novel Subcutaneous Formulation of Daratumumab Administered to Multiple Myeloma Patients

We report the population pharmacokinetic (PK) and exposure-response analyses of a novel subcutaneous formulation of daratumumab (DARA) using data from 3 DARA subcutaneous monotherapy studies (PAVO Part 2, MMY1008, COLUMBA) and 1 combination therapy study (PLEIADES). Results were based on 5159 PK samples from 742 patients (DARA 1800 mg subcutaneously, n = 487 [monotherapy, n = 288; combination therapy, n = 199]; DARA 16 mg/kg intravenously, n = 255 [all monotherapy, in COLUMBA]; age, 33-92 years; weight, 28.6-147.6 kg). Subcutaneous and intravenous DARA monotherapies were administered once every week for cycles 1-2, once every 2 weeks for cycles 3-6, and once every 4 weeks thereafter (1 cycle is 28 days). The subcutaneous DARA combination therapy was administered with the adaptation of corresponding standard-of-care regimens. PK samples were collected between cycle 1 and cycle 12. Among monotherapy studies, throughout the treatment period, subcutaneous DARA provided similar/slightly higher trough concentrations (Ctrough) versus intravenous DARA, with lower maximum concentrations and smaller peak-to-trough fluctuations. The PK profile was consistent between subcutaneous DARA monotherapy and combination therapies. The exposure-response relationship between daratumumab PK and efficacy or safety end points was similar for subcutaneous and intravenous DARA. Although the ≤65-kg subgroup reported a higher incidence of neutropenia, no relationship was found between the incidence of neutropenia and exposure, which was attributed, in part, to the preexisting imbalance in neutropenia between subcutaneous DARA (45.5%) and intravenous DARA (19%) in patients ≤50 kg. A flat relationship was observed between body weight and any grade and at least grade 3 infections. The results support the DARA 1800-mg subcutaneous flat dose as an alternative to the approved intravenous DARA 16 mg/kg.The clinical studies and the analyses presented here were supported by research funding from Janssen Research & Development, LLC

Phase 1 study of selinexor plus carfilzomib and dexamethasone for the treatment of relapsed/refractory multiple myeloma

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150566/1/bjh15969.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150566/2/bjh15969_am.pd

Twice‐weekly ixazomib in combination with lenalidomide‐dexamethasone in patients with newly diagnosed multiple myeloma

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144661/1/bjh15394.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144661/2/bjh15394_am.pd

Daratumumab monotherapy for patients with intermediate-risk or high-risk smoldering multiple myeloma: a randomized, open-label, multicenter, phase 2 study (CENTAURUS)

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Daratumumab monotherapy in patients with treatment-refractory multiple myeloma (SIRIUS): an open-label, randomised, phase 2 trial

BACKGROUND: New treatment options are needed for patients with multiple myeloma that is refractory to proteasome inhibitors and immunomodulatory drugs. We assessed daratumumab, a novel CD38-targeted monoclonal antibody, in patients with refractory multiple myeloma. METHODS: In this open-label, multicentre, phase 2 trial done in Canada, Spain, and the USA, patients (age ≥18 years) with multiple myeloma who were previously treated with at least three lines of therapy (including proteasome inhibitors and immunomodulatory drugs), or were refractory to both proteasome inhibitors and immunomodulatory drugs, were randomly allocated in a 1:1 ratio to receive intravenous daratumumab 8 mg/kg or 16 mg/kg in part 1 stage 1 of the study, to decide the dose for further assessment in part 2. Patients received 8 mg/kg every 4 weeks, or 16 mg/kg per week for 8 weeks (cycles 1 and 2), then every 2 weeks for 16 weeks (cycles 3-6), and then every 4 weeks thereafter (cycle 7 and higher). The allocation schedule was computer-generated and randomisation, with permuted blocks, was done centrally with an interactive web response system. In part 1 stage 2 and part 2, patients received 16 mg/kg dosed as in part 1 stage 1. The primary endpoint was overall response rate (partial response [PR] + very good PR + complete response [CR] + stringent CR). All patients who received at least one dose of daratumumab were included in the analysis. The trial is registered with ClinicalTrials.gov, number NCT01985126. FINDINGS: The study is ongoing. In part 1 stage 1 of the study, 18 patients were randomly allocated to the 8 mg/kg group and 16 to the 16 mg/kg group. Findings are reported for the 106 patients who received daratumumab 16 mg/kg in parts 1 and 2. Patients received a median of five previous lines of therapy (range 2-14). 85 (80%) patients had previously received autologous stem cell transplantation, 101 (95%) were refractory to the most recent proteasome inhibitors and immunomodulatory drugs used, and 103 (97%) were refractory to the last line of therapy. Overall responses were noted in 31 patients (29.2%, 95% CI 20.8-38.9)-three (2.8%, 0.6-8.0) had a stringent CR, ten (9.4%, 4.6-16.7) had a very good PR, and 18 (17.0%, 10.4-25.5) had a PR. The median time to first response was 1.0 month (range 0.9-5.6). Median duration of response was 7.4 months (95% CI 5.5-not estimable) and progression-free survival was 3.7 months (95% CI 2.8-4.6). The 12-month overall survival was 64.8% (95% CI 51.2-75.5) and, at a subsequent cutoff, median overall survival was 17.5 months (95% CI 13.7-not estimable). Daratumumab was well tolerated; fatigue (42 [40%] patients) and anaemia (35 [33%]) of any grade were the most common adverse events. No drug-related adverse events led to treatment discontinuation. INTERPRETATION: Daratumumab monotherapy showed encouraging efficacy in heavily pretreated and refractory patients with multiple myeloma, with a favourable safety profile in this population of patients. FUNDING: Janssen Research & Development

Ixazomib-lenalidomide-dexamethasone in routine clinical practice: Effectiveness in relapsed/refractory multiple myeloma

[Aim]: To evaluate the effectiveness and safety of ixazomib-lenalidomide-dexamethasone (IRd) in relapsed/refractory multiple myeloma in routine clinical practice. Patients & methods: Patient-level data from the global, observational INSIGHT MM and the Czech Registry of Monoclonal Gammopathies were integrated and analyzed.[Results]: At data cut-off, 263 patients from 13 countries were included. Median time from diagnosis to start of IRd was 35.8 months; median duration of follow-up was 14.8 months. Overall response rate was 73%, median progression-free survival, 21.2 months and time-to-next therapy, 33.0 months. Ixazomib/lenalidomide dose reductions were required in 17%/36% of patients; 32%/30% of patients discontinued ixazomib/lenalidomide due to adverse events.[Conclusion]: The effectiveness and safety of IRd in routine clinical practice are comparable to those reported in TOURMALINE-MM1.This work was supported by Millennium Pharmaceuticals, Inc., Cambridge, MA, USA, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited