Stem cell collection and hematological recovery in the Fondazione Italiana Linfomi (FIL) MCL0208 clinical trial.

In the frontline high-dose phase 3 FIL-MCL0208 trial (NCT02354313), 8% of enrolled mantle cell lymphoma (MCL) patients could not be randomised to receive lenalidomide (LEN) maintenance vs observation after autologous stem cell transplantation (ASCT) due to inadequate hematological recovery and 52% of those who started LEN, needed a dose reduction due to toxicity. We therefore focused on the role played by CD34 + hematopoietic stem cells (PBSC) harvesting and reinfusion on toxicity and outcome. Overall, 90% (n = 245) of enrolled patients who underwent the first leukapheresis collected ≥ 4 × 106 PBSC/kg, 2.6% (n = 7) mobilized < 4 × 106 PBSC/kg and 7.7% (n = 21) failed the collection. Similar results were obtained for the planned second leukapheresis, with only one patient failing both attempts. Median count of reinfused PBSC was 5 × 106/kg and median time to recovery from neutropenia G4 was 10 days from ASCT. No impact of mobilizing subtype or number of reinfused PBSC on hematological recovery and LEN dose reduction was noted. At a median follow-up of 75 months from ASCT, PFS and OS of transplanted patients were 50% and 73%, respectively. A long lasting G4 neutropenia after ASCT (> 10 days) was associated with a worse outcome, both in terms of PFS and OS. In conclusion, although the harvesting procedures proved feasible for younger MCL patients, long-lasting cytopenia following ASCT remains a significant issue: this can hinder the administration of effective maintenance therapies, potentially increasing the relapse rate and negatively affecting survival outcomes.

Genomic and immune determinants of resistance to daratumumab-based therapy in relapsed refractory multiple myeloma.

Targeted immunotherapy combinations, including the anti-CD38 monoclonal antibody (MoAb) daratumumab, have shown promising results in patients with relapsed/refractory multiple myeloma (RRMM), leading to a considerable increase in progression-free survival. However, a large fraction of patients inevitably relapse. To understand this, we investigated 32 relapsed MM patients treated with daratumumab, lenalidomide, and dexamethasone (Dara-Rd; NCT03848676). We conducted an integrated analysis using whole-genome sequencing (WGS) and flow cytometry in patients with RRMM. WGS before and after treatment pinpointed genomic drivers associated with early progression, including RPL5 loss, APOBEC mutagenesis, and gain of function structural variants involving MYC and chromothripsis. Flow cytometry on 202 blood samples, collected every 3 months until progression for 31 patients, revealed distinct immune changes significantly impacting clinical outcomes. Progressing patients exhibited significant depletion of CD38-positive NK cells, persistence of T-cell exhaustion, and reduced depletion of regulatory T cells over time. These findings underscore the influence of immune composition and daratumumab-induced immune changes in promoting MM resistance. Integrating genomics and flow cytometry unveiled associations between adverse genomic features and immune patterns. Overall, this study sheds light on the intricate interplay between genomic complexity and the immune microenvironment driving resistance to Dara-Rd in patients with RRMM.

Comprehensive analysis of serum cytokines in patients with multiple myeloma before and after lenalidomide and dexamethasone.

Multiple myeloma (MM) is an incurable B-cell malignancy often accompanied by profound immunodeficiency. Lenalidomide (Len) is an immunomodulatory drug that exerts promising therapeutic effects on MM through the immune system. However, predictive markers related to the effects of Len treatment are not fully understood. This study aimed to identify candidate biomarkers for predicting the clinical efficacy of Len and dexamethasone (Ld) therapy through a comprehensive analysis of serum cytokines. The levels of 48 cytokines in the serum of patients with MM just before Ld therapy (n = 77), at the time of best response (n = 56), and at disease progression (n = 49) were measured and evaluated. Patients with high IL-18 and M-CSF levels showed significantly shorter progression-free survival and overall survival (OS). In contrast, patients with high PDGF-BB levels had longer survival. Moreover, low levels of G-CSF, IL-7, IL-8, and SDF-1α were associated with shorter OS after Ld therapy. During Ld therapy, pro-inflammatory cytokines such as IL-2Rα, IL-18, and TNF-α were decreased, while IFN-γ was increased. IL-4 and IL-6 levels increased during disease progression. In conclusion, this study provides a better understanding of the association between cytokines and the efficacy of Ld therapy as well as the unique changes in cytokines related to inflammatory and immune responses during Ld therapy.

Daratumumab in transplant-eligible patients with newly diagnosed multiple myeloma: final analysis of clinically relevant subgroups in GRIFFIN.

The randomized, phase 2 GRIFFIN study (NCT02874742) evaluated daratumumab plus lenalidomide/bortezomib/dexamethasone (D-RVd) in transplant-eligible newly diagnosed multiple myeloma (NDMM). We present final post hoc analyses (median follow-up, 49.6 months) of clinically relevant subgroups, including patients with high-risk cytogenetic abnormalities (HRCAs) per revised definition (del[17p], t[4;14], t[14;16], t[14;20], and/or gain/amp[1q21]). Patients received 4 induction cycles (D-RVd/RVd), high-dose therapy/transplant, 2 consolidation cycles (D-RVd/RVd), and lenalidomide±daratumumab maintenance (≤ 2 years). Minimal residual disease-negativity (10-5) rates were higher for D-RVd versus RVd in patients ≥ 65 years (67.9% vs 17.9%), with HRCAs (54.8% vs 32.4%), and with gain/amp(1q21) (61.8% vs 28.6%). D-RVd showed a trend toward improved progression-free survival versus RVd (hazard ratio [95% confidence interval]) in patients ≥ 65 years (0.29 [0.06-1.48]), with HRCAs (0.38 [0.14-1.01]), and with gain/amp(1q21) (0.42 [0.14-1.27]). In the functional high-risk subgroup (not MRD negative at the end of consolidation), the hazard ratio was 0.82 (0.35-1.89). Among patients ≥ 65 years, grade 3/4 treatment-emergent adverse event (TEAE) rates were higher for D-RVd versus RVd (88.9% vs 77.8%), as were TEAEs leading to discontinuation of ≥ 1 treatment component (37.0% vs 25.9%). One D-RVd patient died due to an unrelated TEAE. These results support the addition of daratumumab to RVd in transplant-eligible patients with high-risk NDMM. Video Abstract.

The impact of continuous lenalidomide maintenance treatment on people living with multiple myeloma-a single-centre, qualitative service evaluation study.

PURPOSE: Continuous lenalidomide maintenance treatment after autologous stem cell transplantation delivers improvement in progression free and overall survival among newly diagnosed multiple myeloma patients and has been the standard of care in the UK since March 2021. However, there is scant information about its impact on patients' day-to-day lives. This service evaluation aimed to qualitatively assess patients receiving lenalidomide treatment at a cancer centre in London, in order that the service might better align with needs and expectations of patients. METHODS: We conducted 20 semi-structured interviews among myeloma patients who were on continuous lenalidomide maintenance treatment at a specialist cancer centre in London. Members of the clinical team identified potentially eligible participants to take part, and convenience sampling was used to select 10 male and 10 female patients, median age of 58 (range, 45-71). The median treatment duration was 11 months (range, 1-60 months). Participants were qualitatively interviewed following the same semi-structured interview guide, which was designed to explore patient experience and insights of lenalidomide. Reflexive thematic analysis was used for data analysis. RESULTS: Four overarching themes were as follows: (i) lenalidomide: understanding its role and rationale; (ii) reframing the loss of a treatment-free period to a return to normal life; (iii) the reality of being on lenalidomide: balancing hopes with hurdles; (iv) gratitude and grievances: exploring mixed perceptions of care and communication. Results will be used to enhance clinical services by tailoring communication to better meet patients' preferences when making treatment decisions. CONCLUSION: This study highlights that most patients feel gratitude for being offered continuous lenalidomide and perceive it as alleviating some fears concerning relapse. It reveals variations in side effects in different age groups; younger patients reported no/negligible side effects, whilst several older patients with comorbidities described significant symptom burden, occasionally leading to treatment discontinuation which caused distress at the perceived loss of prolonged remission. Future research should prioritise understanding the unique needs of younger patients living with multiple myeloma.

Acute hypoxic respiratory failure due to Lenalidomide-induced interstitial pneumonitis in a patient with multiple myeloma.

BACKGROUND: Patients with multiple myeloma are immunosuppressed due to both the disease itself and immunosuppressive therapies. Thus, when presenting with respiratory failure and pulmonary opacities, pneumonia must be considered. However, while rare, immunomodulating medications used in the treatment of multiple myeloma can also cause potentially life-threatening respiratory failure, a distinction which has important treatment implications. CASE PRESENTATION: An 80-year-old male with recently diagnosed multiple myeloma undergoing treatment with lenalidomide and daratumumab presented with acute, rapidly progressive hypoxic respiratory failure ultimately requiring intubation and mechanical ventilatory support. Imaging revealed bilateral pulmonary opacities, however infectious workup was negative, and he was ultimately diagnosed with lenalidomide-induced interstitial pneumonitis, a rare but serious adverse effect of this medication. He was treated with drug discontinuation and methylprednisolone, and quickly recovered. CONCLUSION: Lenalidomide is an immunomodulating medication used in the treatment of multiple myeloma, and is associated with rare but serious cases of drug-induced interstitial pneumonitis. Thus, if a patient receiving lenalidomide develops shortness of breath and/or hypoxia, drug-induced pneumonitis must be on the differential. Permanent drug discontinuation with or without corticosteroids is the mainstay of treatment, and patients are often able to fully recover, underscoring the need for early recognition of this condition.

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

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

POEMS syndrome with undetectable M-protein: a case report and literature review.

BACKGROUND: Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome is a rare plasma cell (PC) neoplasm with associated paraneoplastic syndrome. According to the current diagnostic criteria, peripheral polyneuropathy and monoclonal PC proliferative disorder represent two mandatory criteria. CASE PRESENTATION: We report a 54-year-old male with peripheral neuropathy of bilateral lower limbs, sclerotic bone lesions, elevated vascular endothelial growth factor (VEGF) levels, splenomegaly, extravascular volume overload, endocrinopathy, and skin hemangiomas. Of note, serum and urine protein electrophoresis (PEP) and immunofixation electrophoresis (IFE) of this patient indicated undetectable M-protein and the normal ratio of free light chains κ and λ (FLC-R (κ/λ)). No monoclonal PCs were found in bone marrow examinations or biopsy of diseased bones. However, his clinical manifestations matched most of the diagnostic criteria. After excluding other diseases that are easily confused with POEMS syndrome, the diagnosis of variant POEMS syndrome with undetectable M-protein was proposed. The patient obtained clinically significant improvement and elevated VEGF returned to normal after 6 months of treatment with lenalidomide plus dexamethasone. CONCLUSIONS: Monoclonal PC dyscrasia (M-protein) while being a mandatory criterion for POEMS syndrome is undetectable in a considerable amount of patients that otherwise demonstrate typical symptoms. Here, we reported a case of variant POEMS syndrome with featured clinical manifestations, elevated VEGF levels, and good response to therapies targeting PCs but no evidence of M-protein. Therefore, negative results in M-protein and monoclonal PCs aren't enough to reject the diagnosis of POEMS syndrome. It is imperative to recognize the variant form of POEMS syndrome.

Predictive factors for peripheral blood stem cell mobilization in multiple myeloma in the era of novel therapies: A single-center experience.

OBJECTIVE: Multiple myeloma (MM) is the leading indication of autologous hematopoietic stem cell transplantation. The aim of this study was to determine the incidence of mobilization failure and characterize the risk factors associated with poor mobilization (PM) of MM patients in novel therapies era. METHODS: We conducted a retrospective study of 211 MM patients who received their first peripheral blood stem cells (PBSC) mobilization at our single center. The following data were collected: age, gender, clinical stage, disease status, complete blood cell count, induction regimen, CD34+ cell count in peripheral blood (PB), and PBSC collections. RESULTS: In addition to conventional drugs, 22 (10.4%) patients received daratumumab containing induction, and 33 (15.6%) patients used plerixafor for poor mobilization (pre-apheresis PB CD34+ cells <20/µL). Failure of collection occurred in 24 (11.4%) patients and was correlated with low white blood cell (WBC), ≥3 cycles of lenalidomide treatment before mobilization, steady-state mobilization and nouse of plerixafor are associated with mobilization failure. Daratumumab-based induction treatment ≥2 courses, albumin >41 g/L before mobilization, and steady-state mobilization were risk factors for PM in subgroups of patients treated with lenalidomide for <3 courses. In addition, Hepatitis B virus infection at baseline, thalassemia and measurable residual disease positivity were recognized as predictive factors for PM in subset of chemo-mobilization patients. CONCLUSION: In addition to some well-recognized risk factors, baseline WBC count and daratumumab exposure ≥2 courses before mobilization were revealed as the predictive factors of mobilization failure, providing consultation for preemptive use of plerixafor.

Combination Targeted Therapy in Relapsed Diffuse Large B-Cell Lymphoma.

BACKGROUND: The identification of oncogenic mutations in diffuse large B-cell lymphoma (DLBCL) has led to the development of drugs that target essential survival pathways, but whether targeting multiple survival pathways may be curative in DLBCL is unknown. METHODS: We performed a single-center, phase 1b-2 study of a regimen of venetoclax, ibrutinib, prednisone, obinutuzumab, and lenalidomide (ViPOR) in relapsed or refractory DLBCL. In phase 1b, which included patients with DLBCL and indolent lymphomas, four dose levels of venetoclax were evaluated to identify the recommended phase 2 dose, with fixed doses of the other four drugs. A phase 2 expansion in patients with germinal-center B-cell (GCB) and non-GCB DLBCL was performed. ViPOR was administered every 21 days for six cycles. RESULTS: In phase 1b of the study, involving 20 patients (10 with DLBCL), a single dose-limiting toxic effect of grade 3 intracranial hemorrhage occurred, a result that established venetoclax at a dose of 800 mg as the recommended phase 2 dose. Phase 2 included 40 patients with DLBCL. Toxic effects that were observed among all the patients included grade 3 or 4 neutropenia (in 24% of the cycles), thrombocytopenia (in 23%), anemia (in 7%), and febrile neutropenia (in 1%). Objective responses occurred in 54% of 48 evaluable patients with DLBCL, and complete responses occurred in 38%; complete responses were exclusively in patients with non-GCB DLBCL and high-grade B-cell lymphoma with rearrangements of MYC and BCL2 or BCL6 (or both). Circulating tumor DNA was undetectable in 33% of the patients at the end of ViPOR therapy. With a median follow-up of 40 months, 2-year progression-free survival and overall survival were 34% (95% confidence interval [CI], 21 to 47) and 36% (95% CI, 23 to 49), respectively. CONCLUSIONS: Treatment with ViPOR was associated with durable remissions in patients with specific molecular DLBCL subtypes and was associated with mainly reversible adverse events. (Funded by the Intramural Research Program of the National Cancer Institute and the National Center for Advancing Translational Sciences of the National Institutes of Health and others; ClinicalTrials.gov number, NCT03223610.).

A real-life study of daratumumab combinations in newly diagnosed patients with light chain (AL) amyloidosis.

Daratumumab-based regimens are the new standard of care for newly diagnosed patients with AL amyloidosis based on the results of the ANDROMEDA study. However, real-world data on daratumumab efficacy in upfront therapy in unselected patients are scanty. In the framework of a prospective observational study, we investigated the efficacy and safety of daratumumab in 88 newly diagnosed patients, including subjects with IIIb cardiac stage (26%) or myeloma defining events (29%). Daratumumab was administered with bortezomib in 50 (56%) patients, lenalidomide in 31 (35%), and monotherapy in 7 (8%). The rate of serious adverse events was low (16%). The overall hematologic response rate was 75% with 52 (59%) patients attaining at least a very good partial response (VGPR) at six months. Amongst patients evaluable for organ response, the rate of cardiac and renal responses at 6 months was 31% and 21%, respectively. Comparing stage IIIb patients with the remaining ones, the rate of profound hematologic response was not significantly different (≥VGPR 57% vs. 59%, p 0.955) likewise the rate of cardiac (33% vs. 30%, p 0.340) and renal (40% vs. 16%, p 0.908) responses. Daratumumab-based regimens demonstrated to be safe and effective in treatment-naïve AL amyloidosis even in advanced stage disease.

Brentuximab vedotin therapy followed by autologous peripheral stem cell transplantation as a viable treatment option for an older adult with transformed lymphoma: a case report and literature review.

This report presents a case involving a woman aged >65 years who had been diagnosed with marginal zone lymphoma 3 years prior. The patient was hospitalized with enlarged inguinal lymph nodes, and pathological examination revealed that the lymphoma had transformed into diffuse large B-cell lymphoma. After two cycles of brentuximab vedotin in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (BV-R-CHP) chemotherapy, the patient achieved complete remission. This treatment was followed by autologous hematopoietic stem cell transplantation and lenalidomide maintenance therapy. At the last follow-up, the patient had been in continuous remission for 24 months. This case study suggests that the utilization of BV and R-CHP in conjunction can result in rapid remission, and it can be followed by autologous hematopoietic stem cell transplantation and maintenance therapy with lenalidomide. This treatment approach exhibits potential as a viable option for older individuals with transformed lymphoma.

Circulating miR-16 and miR-21 Levels in Multiple Myeloma: Prognostic Significance of Survival and Response to Lenalidomide Treatment.

MicroRNAs (miRNAs), particularly miR-16 and miR-21, play a crucial role in multiple myeloma (MM) pathogenesis by regulating gene expression. This study evaluated the prognostic significance of circulating miR-16 and miR-21 expression levels in 48 patients with MM at diagnosis treated with lenalidomide-dexamethasone (LD) compared with 15 healthy individuals (HI). All patients were treated with LD, 13 at first line and 35 at relapse, of whom 21 were tested twice at diagnosis and before LD initiation. The results revealed significantly lower levels of miR-16 and miR-21 in patients than in HIs, both at diagnosis and relapse, with decreased miR-16 levels at diagnosis, indicating improved overall survival (OS) (p value 0.024). Furthermore, miR-16 and miR-21 levels were associated with disease markers, while both correlated with the depth of response and mir-16 with sustained response to LD treatment. Ratios of both miR-16 and miR-21 expression levels (prior to LD treatment/diagnosis) below two predicted a shorter time to response (p = 0.027) and a longer time to next treatment (p = 0.042), respectively. These findings suggested a prognostic value for serum miR-16 and miR-21 levels in MM, as their expression levels correlated with disease variables and treatment outcomes.

Immunomodulator adherence in multiple myeloma patients with lower socioeconomic status: a retrospective study.

OBJECTIVE: Poor adherence to oral chemotherapy adversely impacts clinical outcomes and escalates overall healthcare costs. Despite barriers to medication adherence, a significant gap remains in assessing adherence to oral chemotherapy among multiple myeloma (MM) patients with lower socioeconomic status. Hence, our study aims to evaluate immunomodulator adherence in MM patients at a county hospital, primarily serving underrepresented and indigent individuals with low socioeconomic status across the greater Houston area. METHODS: Inclusion criteria composed of patients diagnosed with MM, aged at least 18 years, and treated with lenalidomide or pomalidomide-two widely used immunomodulators-for a minimum of 2 months or having two or more records of dispensation between May 2019 and May 2021. Adherence was gauged using an adjusted version of the medication possession ratio (MPR). RESULTS: Sixty-two patients were enrolled, yielding a mean MPR value of 88% (SD, ± 18.9). Of these, 43 patients (69.3%) demonstrated adherence with an MPR of ≥ 0.90. A significant difference was found in treatment duration between the adherent (mean 8.8 months; SD, ± 7.2) and non-adherent (mean 13.4 months; SD, ± 7.9) groups (p = 0.027). Notably, race/ethnicity demonstrated a significant difference (p = 0.048), driven by disparities in African American and Hispanic representation across adherence levels. CONCLUSION: In summary, our findings highlight race and treatment duration to be predictors of immunomodulator adherence among MM patients with lower socioeconomic status. Further research is imperative to devise and test innovative interventions aimed at enhancing medication adherence, thereby contributing to improved survival and healthcare quality in this population.

Multicolumn Nanoflow Liquid Chromatography with Accelerated Offline Gradient Generation for Robust and Sensitive Single-Cell Proteome Profiling.

Peptide separations that combine high sensitivity, robustness, peak capacity, and throughput are essential for extending bottom-up proteomics to smaller samples including single cells. To this end, we have developed a multicolumn nanoLC system with offline gradient generation. One binary pump generates gradients in an accelerated fashion to support multiple analytical columns, and a single trap column interfaces with all analytical columns to reduce required maintenance and simplify troubleshooting. A high degree of parallelization is possible, as one sample undergoes separation while the next sample plus its corresponding mobile phase gradient are transferred into the storage loop and a third sample is loaded into a sample loop. Selective offline elution from the trap column into the sample loop prevents salts and hydrophobic species from entering the analytical column, thus greatly enhancing column lifetime and system robustness. With this design, samples can be analyzed as fast as every 20 min at a flow rate of just 40 nL/min with close to 100% MS utilization time and continuously for as long as several months without column replacement. We utilized the system to analyze the proteomes of single cells from a multiple myeloma cell line upon treatment with the immunomodulatory imide drug lenalidomide.

Single-cell transcriptional profile of CD34+ hematopoietic progenitor cells from del(5q) myelodysplastic syndromes and impact of lenalidomide.

While myelodysplastic syndromes with del(5q) (del(5q) MDS) comprises a well-defined hematological subgroup, the molecular basis underlying its origin remains unknown. Using single cell RNA-seq (scRNA-seq) on CD34+ progenitors from del(5q) MDS patients, we have identified cells harboring the deletion, characterizing the transcriptional impact of this genetic insult on disease pathogenesis and treatment response. Interestingly, both del(5q) and non-del(5q) cells present similar transcriptional lesions, indicating that all cells, and not only those harboring the deletion, may contribute to aberrant hematopoietic differentiation. However, gene regulatory network (GRN) analyses reveal a group of regulons showing aberrant activity that could trigger altered hematopoiesis exclusively in del(5q) cells, pointing to a more prominent role of these cells in disease phenotype. In del(5q) MDS patients achieving hematological response upon lenalidomide treatment, the drug reverts several transcriptional alterations in both del(5q) and non-del(5q) cells, but other lesions remain, which may be responsible for potential future relapses. Moreover, lack of hematological response is associated with the inability of lenalidomide to reverse transcriptional alterations. Collectively, this study reveals transcriptional alterations that could contribute to the pathogenesis and treatment response of del(5q) MDS.

Differential Analysis of Cereblon Neosubstrates in Rabbit Embryos Using Targeted Proteomics.

Targeted protein degradation is the selective removal of a protein of interest through hijacking intracellular protein cleanup machinery. This rapidly growing field currently relies heavily on the use of the E3 ligase cereblon (CRBN) to target proteins for degradation, including the immunomodulatory drugs (IMiDs) thalidomide, lenalidomide, and pomalidomide which work through a molecular glue mechanism of action with CRBN. While CRBN recruitment can result in degradation of a specific protein of interest (e.g., efficacy), degradation of other proteins (called CRBN neosubstrates) also occurs. Degradation of one or more of these CRBN neosubstrates is believed to play an important role in thalidomide-related developmental toxicity observed in rabbits and primates. We identified a set of 25 proteins of interest associated with CRBN-related protein homeostasis and/or embryo/fetal development. We developed a targeted assay for these proteins combining peptide immunoaffinity enrichment and high-resolution mass spectrometry and successfully applied this assay to rabbit embryo samples from pregnant rabbits dosed with three IMiDs. We confirmed previously reported in vivo decreases in neosubstrates like SALL4, as well as provided evidence of neosubstrate changes for proteins only examined in vitro previously. While there were many proteins that were similarly decreased by all three IMiDs, no compound had the exact same neosubstrate degradation profile as another. We compared our data to previous literature reports of IMiD-induced degradation and known developmental biology associations. Based on our observations, we recommend monitoring at least a major subset of these neosubstrates in a developmental test system to improve CRBN-binding compound-specific risk assessment. A strength of our assay is that it is configurable, and the target list can be readily adapted to focus on only a subset of proteins of interest or expanded to incorporate new findings as additional information about CRBN biology is discovered.

[Efficacy of a Daltuzumab-containing Regimen in Patients with mSMART High-Risk Multiple Myeloma].

OBJECTIVE: To investigate the efficacy and safety of a treatment regimen based on daratumumab in patients with high-risk relapsed refractory multiple myeloma(MM) with mSMART 3.0 score. METHODS: Clinical data were collected from 16 patients with mSMART3.0 score high-risk relapsed refractory MM treated at the Affiliated Hospital of Shandong University of Traditional Chinese Medicine from May 2020 to May 2023, all of whom received daltezumab-based regimen (regimen drugs including dexamethasone, isazomib, bortezomib, lenalidomide). The efficacy and safety of the treatment were retrospectively analyzed. RESULTS: The median age of 16 patients was 63.5 (47-70) years old, including 10 cases of IgG type, 2 cases of IgA type, and 4 cases of light chain type. The curative efficacy was judged in all 16 patients, with an overall response rate of 93.75% (15/16), including 4 cases of strict complete remission (sCR), 1 case of complete remission (CR), 2 case of very good partial remission (VGPR), partial remission (PR) in 5 cases, and minor remission (MR) in 3 cases. The median follow-up time was 11(2-30) months, and the median progression-free survival and median overall survival were not achieved in 16 patients at the median follow-up period. The hematologic adverse effects of the treatment regimen using daratumumab-based were mainly neutropenia, and the non-hematologic adverse effects were mainly infusion-related adverse reactions and infections. CONCLUSION: Daratumumab-based regimen for the treatment of relapsed refractory MM patients with high risk of mSMART3.0 score has better efficacy and safety.