Anti-CD38 monoclonal antibodies in multiple myeloma with gain/amplification of chromosome arm 1q: a review of the literature

INTRODUCTION

Gain/amplification of 1q (+1q) represents one of the most prevalent cytogenetic abnormalities (CAs) observed in multiple myeloma (MM). Historical studies predating the advent of anti-CD38 monoclonal antibodies (moAbs) implicated + 1q in poor prognoses, prompting its integration into novel staging systems. However, with the emergence of daratumumab and isatuximab, two pivotal anti-CD38 moAbs, the landscape of MM therapy has undergone a profound transformation.

AREAS COVERED

This review encompasses a comprehensive analysis of diverse study methodologies, including observational investigations, clinical trials, meta-analyses, and real-world database analyses. By synthesizing these data sources, we aim to provide an overview of the current understanding of + 1q in the context of anti-CD38 moAbs therapies.

EXPERT OPINION

Despite the paucity of available data, evidence suggests a potential mitigating effect of daratumumab on the adverse prognostic implications of + 1q. However, this benefit seems to diminish in patients harboring ≥ 4 copies or with concurrent high-risk CAs. On the other hand, isatuximab demonstrated promising outcomes in the relapsed-refractory setting for + 1q MM patients. Nevertheless, direct comparison between the two compounds is currently challenging. The current evidence firmly supports the integration of anti-CD38 moAb-based therapies as the standard of care for + 1q patients, pending further elucidation.

Bortezomib-induced peripheral neuropathy: Clinical features, molecular basis, and therapeutic approach

Bortezomib is the first-line standard and most effective chemotherapeutic for multiple myeloma; however, bortezomib-induced peripheral neuropathy (BIPN) severely affects the chemotherapy regimen and has long-term impact on patients under maintenance therapy. The pathogenesis of BIPN is poorly understood, and basic research and development of BIPN management drugs are in early stages. Besides chemotherapy dose reduction and regimen modification, no recommended prevention and treatment approaches are available for BIPN apart from the International Myeloma Working Group guidelines for peripheral neuropathy in myeloma. An in-depth exploration of the pathogenesis of BIPN, development of additional therapeutic approaches, and identification of risk factors are needed. Optimizing effective and standardized BIPN treatment plans and providing more decision-making evidence for clinical diagnosis and treatment of BIPN are necessary. This article reviews the recent advances in BIPN research; provides an overview of clinical features, underlying molecular mechanisms, and therapeutic approaches; and highlights areas for future studies.

Real-world treatment patterns in patients initiating third-line therapy for relapsed or refractory multiple myeloma in Germany, Italy, the United Kingdom, France, and Spain

OBJECTIVES

To retrospectively analyze real-world treatment patterns in patients with relapsed/refractory multiple myeloma (RRMM) who initiated third-line treatment in Europe.

METHODS

German and Italian administrative claims data were sourced from the German AOK PLUS health insurance fund and Italian local health units (2016-2020). Data for the United Kingdom (UK), France, and Spain were sourced from medical chart reviews (MCRs) from 2016 to 2018 (historical) and 2019 to 2021 (new) using electronic case report forms.

RESULTS

Across all countries, immunomodulatory imide drug (IMiD)-based regimens were prominent in the third-line setting. From 2016 to 2020, lenalidomide-dexamethasone was most common in Italy (18.0%) and Germany (12.7%). From 2019 to 2021, the most common regimen was ixazomib-lenalidomide-dexamethasone (67.5%) in the UK, pomalidomide-dexamethasone (17.1%) in France, and daratumumab-bortezomib-dexamethasone (15.0%) in Spain. In the historical data (2016-2018), third-line lenalidomide- and pomalidomide-dexamethasone doublet use across the UK (>47%), France (>46%), and Spain (>33%) was high. From historical to new, triplet use increased in Spain (>19% to >60%) as did anti-CD38 agent use in France (15.1% to 51.9%) and Spain (19.7% to 42.1%).

CONCLUSIONS

From 2016 to 2021, third-line regimens were mostly IMiD based. The MCR data demonstrated evolving treatment choices from 2016 to 2018 and 2019 to 2021, providing insights into uptake of novel agents and current RRMM European clinical practice.

Adjusted Indirect Treatment Comparison of Progression-Free Survival with D-Rd and VRd Based on MAIA and SWOG S0777 Individual Patient-Level Data

INTRODUCTION

Daratumumab plus lenalidomide and dexamethasone (D-Rd) and bortezomib plus lenalidomide and dexamethasone (VRd) are commonly used treatment combinations for transplant-ineligible (TIE) patients with newly diagnosed multiple myeloma (NDMM). D-Rd and VRd demonstrated superior efficacy relative to lenalidomide and dexamethasone (Rd) in the MAIA and SWOG S0777 trials, respectively, but have not been compared directly in a head-to-head trial. Naïve comparisons of efficacy across the two trials may be biased because MAIA enrolled only TIE patients (median age 73 years), whereas SWOG S0777 enrolled both TIE patients and transplant-eligible patients who chose to defer/refuse frontline stem cell transplantation (median age 63 years). The present study compared progression-free survival (PFS) in TIE patients with NDMM treated with D-Rd versus VRd based on an adjusted indirect treatment comparison (ITC) that leveraged individual patient-level data from MAIA and SWOG S0777.

METHODS

Harmonized inclusion/exclusion criteria (including age ≥ 65 years as a proxy for transplant ineligibility) and propensity-score weighting were used to balance the trial populations on measured baseline characteristics. After differences in trial populations were adjusted for, an anchored ITC was performed wherein within-trial PFS hazard ratios (HRs) for D-Rd versus Rd and VRd versus Rd were estimated and used to make indirect inference about PFS for D-Rd versus VRd.

RESULTS

PFS HRs were 0.52 (95% confidence interval [CI] 0.41-0.67) for D-Rd versus Rd based on MAIA data, 0.88 (95% CI 0.63-1.23) for VRd versus Rd based on SWOG S0777 data, and 0.59 (95% CI 0.39-0.90) for the Rd-anchored ITC of D-Rd versus VRd. Sensitivity and subgroup analyses produced results consistent with the primary results.

CONCLUSION

This anchored ITC demonstrated a greater PFS benefit for D-Rd versus VRd in TIE patients with NDMM. In the absence of head-to-head trials comparing D-Rd and VRd, the present trial may help inform treatment selection in this patient population.

The efficacy and tolerability of bortezomib, thalidomide, and dexamethasone induction therapy with a thalidomide dose step-up strategy in patients with newly diagnosed multiple myeloma: A prospective observational study

BACKGROUND

Thalidomide-containing regimens cause adverse events (AEs) that may require a reduction in treatment intensity or even treatment discontinuation in patients with multiple myeloma. As thalidomide toxicity is dose-dependent, identifying the most appropriate dose for each patient is essential.

AIMS

This study aimed to investigate the effects of a thalidomide dose step-up strategy on treatment response and progression-free survival (PFS).

METHODS AND RESULTS

This prospective observational study included 93 patients with newly diagnosed multiple myeloma (NDMM) who received bortezomib, thalidomide, and dexamethasone (VTD). The present study assessed the incidence of thalidomide dose reduction and discontinuation, the overall dose intensity, and their effects on therapeutic efficacy. Furthermore, this study used Cox proportional hazard models to analyze the factors contributing to thalidomide intolerability. The results showed the overall response rates in all patients and the evaluable patients were 78.5% and 98.7%, respectively. The median PFS in the study cohort was not reached. The most common thalidomide-related AEs were constipation (32.3%) and skin rash (23.7%), resulting in dose reduction and discontinuation rates of 22.6% and 21.5%, respectively. The responders had a significantly higher average thalidomide dose intensity than the nonresponders (88.6% vs. 42.9%, p < .001).

CONCLUSION

The thalidomide dose step-up approach is a viable option for patients with NDMM receiving VTD induction therapy with satisfactory efficacy and tolerability. However, thalidomide intolerance may lead to dose reduction or discontinuation due to unpredictable AEs, leading to lower dose intensity and potentially inferior treatment outcomes. In addition to a dose step-up strategy, optimal supportive care is critical for patients with multiple myeloma receiving VTD induction therapy.

Assessment of prolonged proteasome inhibition through ixazomib-based oral regimen on newly diagnosed and first-relapsed multiple myeloma: A real-world Chinese cohort study

OBJECTIVE

To evaluate the effectiveness, safety, and convenience of in-class transition (iCT) from intravenous bortezomib-based induction to ixazomib-based oral regimens.

METHODS

This retrospective real-world study was conducted in 16 Chinese hospitals between October 2017 and April 2023 and analyzed newly diagnosed (NDMM) and first-line relapsed multiple myeloma (FRMM) patients who attained at least a partial response from bortezomib-based induction therapy, followed by an ixazomib-based oral regimen for 2 year or until disease progression or intolerable toxicity.

RESULTS

The study enrolled 199 patients, median age: 63 years old, male 55.4%, 53% as high risk (HR), and 47% as standard risk. Cytogenetic risk stratification by metaphase fluorescence in situ hybridization (M-FISH), based on the Mayo Clinic risk stratification system. The median duration of total PI therapy was 11 months, with ixazomib-based treatment spanning 6 months. At the 20-month median follow-up, 53% of patients remained on therapy. The 24-month PFS rate was 84.3% from the initiation of bortezomib-based induction and 83.4% from the start of ixazomib-based treatment. Overall response rate (ORR) was 100% post-bortezomib induction and 90% following 6 cycles of the ixazomib-based regimen. Based on the Sankey diagrams, 89.51% of patients maintained or improved their disease response after 2 cycles of iCT, 6 cycles (90.14%), and 12 cycles (80%). The HR level of Mayo was found to be a significant independent factor in a worse remission (hazard ratio (HR) 2.55; p = 0.033). Ixazomib's safety profile aligned with previous clinical trial data, with 49% of patients experiencing at least one AE of any grade. The most common AEs included peripheral neuropathy, nausea and vomiting, diarrhea, thrombocytopenia, and granulocytopenia.

CONCLUSION

In the real-world Chinese MM population, NDMM and FRMM patients responded favorably to PI-based continuous therapy, demonstrating substantial response rates. The ixazomib-based iCT allows for sustained PI-based treatment, offering promising efficacy and tolerable AEs.

An Antibody-Drug Conjugate for Multiple Myeloma Prepared by Multi-Arm Linkers

First-line treatment of multiple myeloma, a prevalent blood cancer lacking a cure, using anti-CD38 daratumumab antibody and lenalidomide is often inadequate due to relapse and severe side effects. To enhance drug safety and efficacy, an antibody-drug conjugate, TE-1146, comprising six lenalidomide drug molecules site-specifically conjugated to a reconfigured daratumumab to deliver cytotoxic lenalidomide to tumor cells is developed. TE-1146 is prepared using the HighDAR platform, which employs i) a maleimide-containing "multi-arm linker" to conjugate multiple drug molecules creating a drug bundle, and ii) a designed peptide with a Zn2+-binding cysteine at the C-termini of a reconfigured daratumumab for site-specific drug bundle conjugation. It is shown that TE-1146 remains intact and effectively enters CD38-expressing tumor cells, releasing lenalidomide, leading to enhanced cell-killing effects compared to lenalidomide/daratumumab alone or their combination. This reveals the remarkable potency of lenalidomide once internalized by myeloma cells. TE-1146 precisely delivers lenalidomide to target CD38-overexpressing tumor cells. In contrast, lenalidomide without daratumumab cannot easily enter cells, whereas daratumumab without lenalidomide relies on Fc-dependent effector functions to kill tumor cells.

Dynamic risk prediction model for multiple myeloma: Through deep learning, the model is able to adapt to future data, such as emerging treatment modalities and combinations

This news section offers Cancer readers timely information on events, public policy analysis, topical issues, and personalities. In this issue, a dynamic risk prediction model for multiple myeloma is discussed. Through deep learning, the model is able to adapt to future data, such as emerging treatment modalities and combinations. In addition, global phase 3 results show that bevacizumab with immunotherapy has activity in liver cancer, and D‐VRd is examined as a new standard of care in patients with multiple myeloma.

Characteristics of isatuximab-derived interference in serum protein electrophoresis and immunofixation, and an absence of sustained in vivo interference due to belantamab mafodotin and denosumab

OBJECTIVES

Some therapeutic monoclonal antibodies, like daratumumab and elotuzumab, produce interfering monoclonal bands on serum protein electrophoresis (SPEP) and immunofixation electrophoresis (IFE). Whether other common therapeutic antibodies also produce interference has not been systematically evaluated.

DESIGN AND METHODS

SPEP/IFE from patients receiving isatuximab (48 patients), belantamab mafodotin (BM; 41), and denosumab (41) were retrospectively reviewed for therapeutic antibody interference. Cases exhibiting isatuximab interference were quantified and the maximum duration of isatuximab effect was evaluated. To characterize band position, neat human serum was spiked with BM or denosumab at supratherapeutic concentrations. Band migration patterns were compared on SPEP and IFE, with band position expressed relative to other constant protein fractions.

RESULTS

Isatuximab-induced IFE interference was common (81.3 % of evaluated patients) with a maximum observed duration of 8 weeks. 10.4 % of isatuximab patients had IgG kappa monoclonal gammopathies that co-migrated with the drug; this subset could benefit from HYDRASHIFT 2/4 isatuximab testing. 8.3 % of IFE cases were negative for an isatuximab band but showed large, endogenous M-spikes migrating elsewhere. All patients in this group expired within 1 year of this finding. We hypothesize that an inability to detect isatuximab in this setting corresponds to a large residual myeloma burden that reduces isatuximab serum concentration. This observation may serve as a negative prognostic factor. Spiking studies demonstrated that BM and denosumab produce interference in vitro, but sustained interference was not observed in >40 treated patients.

CONCLUSIONS

Therapeutic antibody interference in patients receiving isatuximab is common, and can persist for at least 8 weeks after administration. >10 % of patients receiving isatuximab may benefit from HYDRASHIFT testing post-therapy. In contrast, BM and denosumab fail to produce sustained interference in treated patients.

Round Table Discussion on Optimal Clinical Trial Design in Precursor Multiple Myeloma

SUMMARY

While the current approach to precursor hematologic conditions is to "watch and wait," this may change with the development of therapies that are safe and extend survival or delay the onset of symptomatic disease. The goal of future therapies in precursor hematologic conditions is to improve survival and prevent or delay the development of symptomatic disease while maximizing safety. Clinical trial considerations in this field include identifying an appropriate at-risk population, safety assessments, dose selection, primary and secondary trial endpoints including surrogate endpoints, control arms, and quality-of-life metrics, all of which may enable more precise benefit-risk assessment.

Randomized comparison between KTd and KRd induction therapy followed by maintenance therapy with K or observation in transplant-ineligible patients with newly diagnosed multiple myeloma

Randomized comparison between KTd and KRd induction followed by second randomization to carfilzomib in transplant-ineligable patients with newly diagnosed multiple myeloma.

A Phase I Trial Evaluating the Addition of Lenalidomide to Patients with Relapsed/Refractory Multiple Myeloma Progressing on Ruxolitinib and Methylprednisolone

BACKGROUND

Ruxolitinib (RUX), an orally administered selective Janus kinase 1/2 inhibitor, has received approval for the treatment of myelofibrosis, polycythemia vera, and graft-versus-host disease. We have previously demonstrated the anti-multiple myeloma effects of RUX alone and in combination with the immunomodulatory agent lenalidomide (LEN) and glucocorticosteroids both pre-clinically and clinically.

OBJECTIVE

This study aims to evaluate whether LEN can achieve clinical activity among patients with multiple myeloma progressing on the combination of RUX and methylprednisolone (MP).

METHODS

In this part of a phase I, multicenter, open-label study, we evaluated the safety and efficacy of RUX and MP for patients with multiple myeloma with progressive disease who had previously received a proteasome inhibitor, LEN, glucocorticosteroids, and at least three prior regimens; we also determined the safety and efficacy of adding LEN at the time of disease progression from the initial doublet treatment. Initially, all subjects received oral RUX 15 mg twice daily and oral MP 40 mg every other day. Those patients who developed progressive disease according to the International Myeloma Working Group criteria then received LEN 10 mg once daily on days 1-21 within a 28-day cycle in addition to RUX and MP, which were administered at the same doses these patients were receiving at the time progressive disease developed.

RESULTS

Twenty-nine subjects (median age 64 years; 18 [62%] male) were enrolled in this part of the study and initially received the two-drug combination of RUX and MP. The median number of prior therapies was six (range 3-12). The overall response rate from this two-drug combination was 31% and the clinical benefit rate was 34%. The best responses were 1 very good partial response, 8 partial responses, 1 minor response, 12 stable disease, and 7 progressive disease. The median progression-free survival was 3.5 months (range  0.5-36.2 months). The median time to response was 3.0 months. The median duration of response was 12.5 months (range 2.8-36.2 months). Twenty (69%) patients who showed progressive disease had LEN added to RUX and MP; all patients had prior exposure to LEN and all but one patient was refractory to their last LEN-containing regimen. After the addition of LEN, the overall response rate was 30% and the clinical benefit rate was 40%. The best responses of patients following the addition of LEN were 2 very good partial responses, 4 partial responses, 2 minor responses, 8 stable disease, and 4 progressive disease. The median time to response was 2.6 months (range 0.7-15.0 months). The median duration of response was not reached. The median progression-free survival following the addition of LEN was 3.5 months (range 0.3-25.9 months).

CONCLUSIONS

For patients with multiple myeloma, treatment with RUX and MP is effective and well tolerated, and LEN can be used to extend the benefit of this RUX-based treatment.

CLINICAL TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov, NCT03110822, and is ongoing.

Impact of elranatamab on quality of life: Patient-reported outcomes from MagnetisMM-3

The physical and emotional burden of relapsed or refractory multiple myeloma (RRMM) has been strongly correlated with declining health-related quality of life (QOL) in the patients it affects. This analysis evaluated patient-reported outcomes (PROs) from B-cell maturation antigen (BCMA)-naive (n = 123) and -exposed (n = 64) patients with RRMM enrolled in the MagnetisMM-3 study (NCT04649359) and treated with the humanized, bispecific BCMA-CD3 antibody elranatamab. Patients received two step-up doses of elranatamab (12 mg on day 1, 32 mg on day 4) before starting the full dose of 76 mg on day 8 (each cycle = 28 days). Global health status, functioning and symptom data were collected electronically using validated and myeloma-specific questionnaires. Improvements in PROs occurred early, with marked reductions in pain and disease symptoms and notable improvements in patients' outlook for their future health. Additionally, 40.2% of BCMA-naive and 52.6% of BCMA-exposed patients perceived their disease as 'a little better' or 'much better' by Cycle 1, Day 15. The results from this analysis demonstrated that elranatamab maintained or improved symptomology and general health status, regardless of prior BCMA-directed therapy. Thus, in addition to its clinical benefits, elranatamab therapy may sustain or improve QOL in heavily pretreated patients with RRMM.

Prognostic factors in 448 newly diagnosed multiple myeloma receiving bortezomib-based induction: impact of ASCT, transplant refusal and high-risk MM

In Hong Kong, newly diagnosed multiple myeloma (NDMM) receives bortezomib-based triplet induction. Upfront autologous stem cell transplant (ASCT) is offered to transplant eligible (TE) patients (NDMM ≤ 65 years of age), unless medically unfit (TE-unfit) or refused (TE-refused). Data was retrieved for 448 patients to assess outcomes. For the entire cohort, multivariate analysis showed that male gender (p = 0.006), international staging system (ISS) 3 (p = 0.003), high lactate dehydrogenase (LDH) (p = 7.6 × 10-7) were adverse predictors for overall survival (OS), while complete response/ near complete response (CR/nCR) post-induction (p = 2.7 × 10-5) and ASCT (p = 4.8 × 10-4) were favorable factors for OS. In TE group, upfront ASCT was conducted in 252 (76.1%). Failure to undergo ASCT in TE patients rendered an inferior OS (TE-unfit p = 1.06 × 10-8, TE-refused p = 0.002) and event free survival (EFS) (TE-unfit p = 0.00013, TE-refused p = 0.002). Among TE patients with ASCT, multivariate analysis showed that age ≥ 60 (p = 8.9 × 10-4), ISS 3 (p = 0.019) and high LDH (p = 2.6 × 10-4) were adverse factors for OS. In those with high-risk features (HR cytogenetics, ISS 3, R-ISS 3), ASCT appeared to mitigate their adverse impact. Our data reaffirmed the importance of ASCT. The poor survival inherent with refusal of ASCT should be recognized by clinicians. Finally, improved outcome with ASCT in those with high-risk features warrant further studies.

Multiple Myeloma

Multiple myeloma (MM) is a cancer that arises from plasma cells in bone marrow. Approximately 35,730 Americans received a new diagnosis and MM will claim the lives of an estimated 12,590 people in 2023. Complications of the disease process include anemia, leukopenia, thrombocytopenia, renal failure, severe pain, bone loss, and hypercalcemia. Patients with MM have a high risk for pathological fractures. For most forms of MM there are effective treatments that may result in long-term remission using multi-drug regimens. Although the medications approved in the United States to treat MM generally produce good outcomes, they have serious, and potentially life-threatening adverse effects. In addition, patients with specific genetic variations are at high risk for relapse. Communication with the oncology team and early intervention in the event of adverse effects of medications, complications of the disease process, or evidence of relapse are important to obtain the best possible outcome. Patients are easily overwhelmed with a three- to four-drug treatment regimen with some drugs given intravenously and/or subcutaneously at the clinic, and others taken orally at home on specific days of each 28-day cycle. Home care nursing is needed to assess for tolerance, adverse effects, and to address patient concerns. Medication management and teaching are very important in guiding patients to safely manage a schedule that changes daily. In addition, the high risk of pathological fractures and serious injury if the patient should fall supports the need for physical and occupational therapy fall prevention and safety education and exercise programs to help avert decline in functional status and combat cancer-related fatigue.

Peripheral Ulcerative Keratopathy following Systemic Treatment with Bortezomib: A Case Report

A 60-year-old patient was diagnosed with multiple myeloma in November 2020, and started treatment in December 2020 with bortezomib, dexamethasone, and thalidomide. Four months later, he presented to the ophthalmology emergency department with inflammation and pain in the left eye. Examination of the anterior segment revealed severe, mixed anterior squamous blepharitis with significant bilateral palpebral inflammation, dysfunction of the meibomian glands, and several styes on both eyelids bilaterally. A peripheral ulcerative keratopathy was detected while examining the left eye cornea, with an inferior infiltrate and significant thinning, approximately 5 mm in length, at the limbal margin (Figure 1). Tear break-up time was shortened bilaterally. In addition to palpebral hygiene and oral treatment with doxycycline 100 mg every 24 hours, the patient was prescribed the following topical treatment without preservatives: artificial tears with lipid emulsion, netilmicin 0,3% 0,4 ml eye drops every 6 hours and dexamethasone 1 mg/ml every 8 hours.

Clinical outcomes of pomalidomide-based and daratumumab-based therapies in patients with relapsed/refractory multiple myeloma: A real-world cohort study in China

BACKGROUND

Comparative investigations evaluating the efficacy of pomalidomide-based (Pom-based) versus daratumumab-based (Dara-based) therapies in patients with relapsed/refractory multiple myeloma (RRMM) remain scarce, both in randomized controlled trials and real-world studies.

METHODS

This retrospective cohort study included 140 RRMM patients treated with Pom-based or Dara-based or a combination of pomalidomide and daratumumab (DPd) regimens in a Chinese tertiary hospital between December 2018 and July 2023.

RESULTS

The overall response rates (ORR) for Pom-based (n = 48), Dara-based (n = 68), and DPd (n = 24) groups were 57.8%, 84.6%, and 75.0%, respectively (p = 0.007). At data cutoff on August 1, 2023, the median progression-free survival (PFS) was 5.7 months (95% CI: 5.0-6.5) for the Pom-based group, 10.5 months (5.2-15.8) for the Dara-based group, and 6.7 months (4.0-9.3) for the DPd group (p = 0.056). Multivariate analysis identified treatment regimens (Dara-based vs. Pom-based, DPd vs. Pom-based) and Eastern Cooperative Oncology Group performance status (ECOG PS) as independent prognostic factors for PFS. In the subgroups of patients aged >65 years, with ECOG PS ≥2, lines of therapy ≥2, extramedullary disease or double-refractory disease (refractory to both lenalidomide and proteasome inhibitors), the superiority of Dara-based regimens over Pom-based regimens was not evident. A higher incidence of infections was observed in patients receiving Dara-based and DPd regimens (Pom-based 39.6% vs. Dara-based 64.7% vs. DPd 70.8%, p = 0.009).

CONCLUSIONS

In real-world settings, Pom-based, Dara-based, and DPd therapies exhibited favorable efficacy in patients with RRMM. Dara-based therapy yielded superior clinical response and PFS compared to Pom-based therapy.

Clinical status of established MRONJ in oncology patients continuing bone-modifying agents

The continuation of bone-modifying agents (BMAs) in patients with established medication-related osteonecrosis of the jaw (MRONJ) is a common concern among dentists and oncologists. There is little evidence supporting or refuting the continued use of BMAs or drug holidays and their impact on established MRONJ. This paper evaluates the outcome of continued BMAs use on the patient's MRONJ status. A retrospective review of 29 oncology patients undergoing active cancer care for either metastatic disease or multiple myeloma was conducted. Data on demographics, oncological status, BMA history and MRONJ status were collected. In total, 90% of patients were judged to have healed or stable MRONJ while continuing BMAs. Most patients (69%) continued the same BMA regime (three- or four-weekly) that they were on before developing MRONJ. The average number of BMAs doses received after an MRONJ diagnosis was 12 (range 1-48). Three patients (10.3%) were found to have MRONJ progression, with two patients developing new sites of necrosis. This real-world dataset suggests that the majority of MRONJ cases remain stable and will not worsen with the continuation of BMAs.

Nirmatrelvir Resistance in an Immunocompromised Patient with Persistent Coronavirus Disease 2019

Although the coronavirus disease 2019 (COVID-19) pandemic is coming to an end, it still poses a threat to the immunocompromised and others with underlying diseases. Especially in cases of persistent COVID-19, new mutations conferring resistance to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) therapies have considerable clinical implications. We present a patient who independently acquired a T21I mutation in the 3CL protease after nirmatrelvir exposure. The T21I mutation in the 3CL protease is one of the most frequent mutations responsible for nirmatrelvir resistance. However, limited reports exist on actual cases of SARS-CoV-2 with T21I and other mutations in the 3CL protease. The patient, a 55 year-old male, had COVID-19 during chemotherapy for multiple myeloma. He was treated with nirmatrelvir early in the course of the disease but relapsed, and SARS-CoV-2 with a T21I mutation in the 3CL protease was detected in nasopharyngeal swab fluid. The patient had temporary respiratory failure but later recovered well. During treatment with remdesivir and dexamethasone, viruses with the T21I mutation in the 3CL protease showed a decreasing trend during disease progression while increasing during improvement. The impact of drug-resistant SARS-CoV-2 on the clinical course, including its severity, remains unknown. Our study is important for examining the clinical impact of nirmatrelvir resistance in COVID-19.

Tigecycline Opposes Bortezomib Effect on Myeloma Cells Decreasing Mitochondrial Reactive Oxygen Species Production

Multiple myeloma is an incurable plasma cell malignancy. Most patients end up relapsing and developing resistance to antineoplastic drugs, like bortezomib. Antibiotic tigecycline has activity against myeloma. This study analyzed tigecycline and bortezomib combination on cell lines and plasma cells from myeloma patients. Apoptosis, autophagic vesicles, mitochondrial mass, mitochondrial superoxide, cell cycle, and hydrogen peroxide were studied by flow cytometry. In addition, mitochondrial antioxidants and electron transport chain complexes were quantified by reverse transcription real-time PCR (RT-qPCR) or western blot. Cell metabolism and mitochondrial activity were characterized by Seahorse and RT-qPCR. We found that the addition of tigecycline to bortezomib reduces apoptosis in proportion to tigecycline concentration. Supporting this, the combination of both drugs counteracts bortezomib in vitro individual effects on the cell cycle, reduces autophagy and mitophagy markers, and reverts bortezomib-induced increase in mitochondrial superoxide. Changes in mitochondrial homeostasis and MYC upregulation may account for some of these findings. These data not only advise to avoid considering tigecycline and bortezomib combination for treating myeloma, but caution on the potential adverse impact of treating infections with this antibiotic in myeloma patients under bortezomib treatment.

Protein degraders - from thalidomide to new PROTACs

Recently, the development of protein degraders (protein-degrading compounds) has prominently progressed. There are two remarkable classes of protein degraders: proteolysis-targeting chimeras (PROTACs) and molecular glue degraders (MGDs). Almost 70 years have passed since thalidomide was initially developed as a sedative-hypnotic drug, which is currently recognized as one of the most well-known MGDs. During the last two decades, a myriad of PROTACs and MGDs have been developed, and the molecular mechanism of action (MOA) of thalidomide was basically elucidated, including identifying its molecular target cereblon (CRBN). CRBN forms a Cullin Ring Ligase 4 with Cul4 and DDB1, whose substrate specificity is controlled by its binding ligands. Thalidomide, lenalidomide and pomalidomide, three CRBN-binding MGDs, were clinically approved to treat several intractable diseases (including multiple myeloma). Several other MGDs and CRBN-based PROTACs (ARV-110 and AVR-471) are undergoing clinical trials. In addition, several new related technologies regarding PROTACs and MGDs have also been developed, and achievements of protein degraders impact not only therapeutic fields but also basic biological science. In this article, I introduce the history of protein degraders, from the development of thalidomide to the latest PROTACs and related technologies.

Induction of IFIT1/IFIT3 and inhibition of Bcl-2 orchestrate the treatment of myeloma and leukemia via pyroptosis

Induction of pyroptosis is proposed as a promising strategy for the treatment of hematological malignancies, but little is known. In the present study, we find clioquinol (CLQ), an anti-parasitic drug, induces striking myeloma and leukemia cell pyroptosis on a drug screen. RNA sequencing reveals that the interferon-inducible genes IFIT1 and IFIT3 are markedly upregulated and are essential for CLQ-induced GSDME activation and cell pyroptosis. Specifically, IFIT1 and IFIT3 form a complex with BAX and N-GSDME therefore directing N-GSDME translocalization to mitochondria and increasing mitochondrial membrane permeabilization and triggering pyroptosis. Furthermore, venetoclax, an activator of BAX and an inhibitor of Bcl-2, displays strikingly synergistic effects with CLQ against leukemia and myeloma via pyroptosis. This study thus reveals a novel mechanism for mitochondrial GSDME in pyroptosis and it also illustrates that induction of IFIT1/T3 and inhibition of Bcl-2 orchestrate the treatment of leukemia and myeloma via pyroptosis.

Targeting PARP14 with lomitapide suppresses drug resistance through the activation of DRP1-induced mitophagy in multiple myeloma

Multiple myeloma (MM) is a hematological malignancy that remains incurable, primarily due to the high likelihood of relapse or development of resistance to current treatments. To explore and discover new medications capable of overcoming drug resistance in MM, we conducted cell viability inhibition screens of 1504 FDA-approved drugs. Lomitapide, a cholesterol-lowering agent, was found to exhibit effective inhibition on bortezomib-resistant MM cells in vitro and in vivo. Our data also indicated that lomitapide decreases the permeability of the mitochondrial outer membrane and induces mitochondrial dysfunction in MM cells. Next, lomitapide treatment upregulated DRP1 and PINK1 expression levels, coupled with the mitochondrial translocation of Parkin, leading to MM cell mitophagy. Excessive mitophagy caused mitochondrial damage and dysfunction induced by lomitapide. Meanwhile, PARP14 was identified as a direct target of lomitapide by SPR-HPLC-MS, and we showed that DRP1-induced mitophagy was crucial in the anti-MM activity mediated by PARP14. Furthermore, PARP14 is overexpressed in MM patients, implying that it is a novel therapeutic target in MM. Collectively, our results demonstrate that DRP1-mediated mitophagy induced by PARP14 may be the cause for mitochondrial dysfunction and damage in response to lomitapide treatment.