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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Plain language summary of the MonumenTAL-1 study of talquetamab in people with relapsed or refractory multiple myeloma

WHAT IS THIS SUMMARY ABOUT?: This plain language summary describes the results of a phase 1 research study (or clinical trial) called MonumenTAL-1 published in the New England Journal of Medicine in December 2022. A phase 1 study is an early clinical trial where researchers evaluate how safe a medicine is at different doses in a small number of people. In the MonumenTAL-1 study, researchers looked at a new medicine under development called talquetamab, for people living with multiple myeloma (a type of blood cancer) who did not respond (refractory), stopped responding (relapsed), or who had difficulty dealing with their previous treatments. HOW WAS THE STUDY CONDUCTED?: The phase 1 MonumenTAL-1 study was performed in 2 parts. Safety was the main focus of Part 1 in which side effects, and how serious they were, were assessed. The results of Part 1 were used to identify doses of talquetamab that were well tolerated, without a need to stop treatment or reduce the doses, for further study in Part 2. Part 2 of the study examined how well talquetamab worked to decrease signs of the cancer and what side effects, and their severity, people experienced at the doses identified in Part 1. WHAT WERE THE RESULTS?: In Part 1 of the study, researchers identified 2 doses of talquetamab for further study: 405 micrograms for every kilogram of body weight (μg/kg) given weekly and 800 μg/kg every other week. All participants experienced at least one side effect of treatment at these 2 doses. Less than half of participants (43% at 405 μg/kg weekly dose and 34% at the 800 μg/kg every other week dose) experienced serious side effects which are those side effects that led to hospitalization, death, or permanent or life-threatening damage). The most common side effects at both doses were a condition known as cytokine release syndrome (CRS); changes in blood cell levels (where different types of cells in the blood were measured); changes in skin such as itching, dry skin, eczema, ulcers or shedding; changes in nails such as discoloration or ridging (lines or dents); and changes in sense of taste such as food tasting sour or metallic. CRS is caused by the overactivation of the immune system (the body's natural defense system) and can result in fever, feeling sick (nausea), being tired (fatigue), low blood pressure, low blood oxygen levels and body aches. Most cases of CRS, as well as most other side effects, were mild or moderate. Most common serious events were CRS, fever and bone pain. Most people had fewer signs of the cancer after taking talquetamab, and the response was similar between the 2 doses. The median duration of response at the 2 identified doses was 8-10 months. WHAT DO THE RESULTS MEAN?: Most of the side effects people experienced when taking talquetamab were mild or moderate. Most people who took talquetamab responded to the treatment even though they hadn't responded or stopped responding to previous multiple myeloma treatments or stopped taking those treatments because they were unable to tolerate them. These results demonstrate the potential of talquetamab as a treatment option in people who have used up other available therapy options. The 2 doses of talquetamab identified here are being examined in a larger group of participants to further test for safety and to test how well people respond

Subcutaneous daratumumab in patients with relapsed or refractory multiple myeloma: Part 2 of the open-label, multicenter, dose-escalation phase 1b study (PAVO)

Intravenous daratumumab is approved for the treatment of multiple myeloma. In Part 1 of the PAVO study, a mix-and-deliver subcutaneous formulation of daratumumab with recombinant human hyaluronidase PH20 (rHuPH20) was well tolerated, with low rates of infusion-related reactions and similar efficacy to intravenous daratumumab. Part 2 of PAVO evaluated a concentrated, pre-mixed co-formulation of daratumumab and rHuPH20 (DARA SC). Patients with ≥2 prior lines of therapy, including a proteasome inhibitor and immunomodulatory drug, received daratumumab (1800 mg) and rHuPH20 (30,000 U) in 15 mL subcutaneously over 3-5 minutes per the approved intravenous monotherapy dosing schedule. Primary endpoints were daratumumab trough concentration at the end of weekly dosing (just prior to the Cycle 3 Day 1 dose) and safety. Twenty-five patients were enrolled in PAVO Part 2. DARA SC achieved daratumumab trough concentrations similar to or greater than intravenous daratumumab 16 mg/kg. The adverse event profile of DARA SC was consistent with intravenous daratumumab, with no new safety concerns and a lower infusion-related reaction rate. At a median follow-up of 14.2 months, the overall response rate was 52%, median duration of response was 15.7 months, and median progression-free survival was 12.0 months. DARA SC 1800 mg was well tolerated in relapsed/refractory multiple myeloma, with a low infusion-related reaction rate and reduced administration time. Daratumumab serum concentrations following DARA SC were consistent with intravenous dosing, and deep and durable responses were observed. Based on these results, ongoing studies are investigating DARA SC in multiple myeloma and other conditions. (ClinicalTrials.gov identifier: 02519452)