Isatuximab as monotherapy and combined with dexamethasone in patients with relapsed/refractory multiple myeloma.

This phase 2 study evaluated isatuximab as monotherapy or combined with dexamethasone in relapsed/refractory multiple myeloma (RRMM). Patients had RRMM refractory to an immunomodulatory drug (IMiD) and a proteasome inhibitor (PI) or had received ≥3 prior lines of therapy incorporating an IMiD and PI. Patients received isatuximab either as monotherapy (20 mg/kg on days 1, 8, 15, and 22 [once weekly] of cycle 1 followed by 20 mg/kg on days 1 and 15 of subsequent cycles; Isa group) or in combination with dexamethasone (40 mg/d [20 mg/d in patients aged ≥75 years] once weekly; Isa-dex group). Treated patients (N = 164) had received a median of 4 (range, 2-10) prior treatment lines. Patients received a median of 5 (1-24) and 7 (1-22) treatment cycles; at data cutoff, 13 (11.9%) of 109 and 15 (27.3%) of 55 patients remained on treatment in the Isa and Isa-dex arms, respectively. Overall response rate (primary efficacy end point) was 23.9% in the Isa arm and 43.6% in the Isa-dex arm (odds ratio, 0.405; 95% confidence interval, 0.192-0.859; P = .008). Median progression-free survival and overall survival were 4.9 and 18.9 months for Isa, and 10.2 and 17.3 months for Isa-dex. Infusion reactions (mostly grade 1/2) and hematologic abnormalities were the most common adverse events. There was a similar incidence of grade 3 or higher infections in both groups (22.0% and 21.8%). In conclusion, addition of dexamethasone to isatuximab increased response rates and survival outcomes with no detrimental effect on safety. This trial was registered at www.clinicaltrials.gov as #NCT01084252.

Comorbidity characteristics of multiple myeloma patients diagnosed in Finland 2005-2016.

Multiple myeloma (MM) patients are predominantly elderly with comorbidities that have an impact on patient mortality and treatment decisions. We previously reported the patient characteristics and overall survival outcomes of the Finnish MM cohort diagnosed between 2005 and 2016 in a nationwide retrospective registry study comprising 3,851 adults. Here, we report detailed comorbidity characteristics for this real-world Finnish MM population at cohort entry and during follow-up. Data on diagnoses and causes of death were obtained from Finnish healthcare data registries and interrogated using various multistate time-to-event models. In the year preceding MM diagnosis, comorbidities (as per Charlson Comorbidity Index definition) were recorded in 38.0% of the cohort, of which 27.9% presented with pre-existing cardiovascular disease (CVD) and 4.8% had suffered a major adverse cardiac event (MACE). At 2 years post-MM diagnosis, cumulative incidence for CVD and MACE more than doubled to 57.1% and 11.4%, respectively, and only 31.9% of the cohort remained CVD-free. Prevalent secondary malignancies were recorded in 16.8% of the patient population at MM diagnosis, with cumulative incidence increasing steadily to 27.5% at 2 years and 33% at 5 years post-diagnosis. The main cause of mortality attributed to MM, CVD, secondary malignancy, or other causes remained stable throughout the follow-up, at an average of 74.2%, 9.4%, 9.8%, and 6.5%, respectively. Prevalence of CVDs and secondary malignancies is high in Finnish patients at MM diagnosis, with older male patients suffering from higher MACE and mortality risk. Proper recording and management of comorbidities alongside novel treatments remain crucial for optimal MM management.

Prognostic significance of esterase gene expression in multiple myeloma.

BACKGROUND: Esterase enzymes differ in substrate specificity and biological function and may display dysregulated expression in cancer. This study evaluated the biological significance of esterase expression in multiple myeloma (MM). METHODS: For gene expression profiling and evaluation of genomic variants in the Institute for Molecular Medicine Finland (FIMM) cohort, bone marrow aspirates were obtained from patients with newly diagnosed MM (NDMM) or relapsed/refractory MM (RRMM). CD138+ plasma cells were enriched and used for RNA sequencing and analysis, and to evaluate genomic variation. The Multiple Myeloma Research Foundation (MMRF) Relating Clinical Outcomes in MM to Personal Assessment of Genetic Profile (CoMMpass) dataset was used for validation of the findings from FIMM. RESULTS: MM patients (NDMM, n = 56; RRMM, n = 78) provided 171 bone marrow aspirates (NDMM, n = 56; RRMM, n = 115). Specific esterases exhibited relatively high or low expression in MM, and expression of specific esterases (UCHL5, SIAE, ESD, PAFAH1B3, PNPLA4 and PON1) was significantly altered on progression from NDMM to RRMM. High expression of OVCA2, PAFAH1B3, SIAE and USP4, and low expression of PCED1B, were identified as poor prognostic markers (P < 0.05). The MMRF CoMMpass dataset provided validation that higher expression of PAFAH1B3 and SIAE, and lower expression of PCED1B, were associated with poor prognosis. CONCLUSIONS: Esterase gene expression levels change as patients progress from NDMM to RRMM. High expression of OVCA2, PAFAH1B3, USP4 and SIAE, and low expression of PCED1B, are poor prognostic markers in MM, suggesting a role for these esterases in myeloma biology.

Characteristics and survival trends in Finnish multiple myeloma patients-a nationwide real-world evidence study.

Current understanding of the epidemiology and outcomes for patients with multiple myeloma in Finland is scarce due to lack of comprehensive real-world evidence in clinical practice. The aim of this study was to gain understanding of epidemiological characteristics and treatment and survival outcomes by utilizing multiple real-world data sources with information of adults treated for active multiple myeloma (MM) during years 2005-2016 in Finland. A total of 3851 adult MM patients with C90.0 diagnosis fulfilling all inclusion criteria were included in the analysis. The average myeloma incidence was six cases per 100,000, which slightly increased (p = 0.011) during the follow-up. The age-standardized incidence was three cases per 100,000 in the years 2005-2016. On average, 25% of patients received autologous stem cell transplantation (ASCT), and this proportion increased during the years 2005-2015 from 17 to 30%. The majority of patients under 65 years of age received ASCT treatment (60.5%), whereas only 8.7% of patients 65 years of age or older were treated with ASCT. The net median overall survival improved by approximately 5 months from 2005-2010 (3.44 years) to 2011-2016 (3.89 years); after adjusting for covariates, this presented an annual 4% reduction in the risk of death. Longer median survival and decreased risk of death indicate improved treatment outcomes from 2005 to 2016 among adult MM patients in Finland.

Morpho-structural characteristics of feet in patients with rheumatoid arthritis: A cross sectional study.

Objective: The aim of this study was to evaluate and classify the types and incidences of foot deformities in patients with Rheumatoid Arthritis (RA). Methods: A cross-sectional study with convenience sample was obtained of 220 patients with foot pain and RA classification criteria (approved by the American College of Rheumatology and the European League against Rheumatism in 2010). A series of outcomes were assessed to measure the morphological characteristics of the feet. The Foot Posture Index (FPI), the Manchester Scale of Hallux Valgus and the Nijmegen classification of forefoot disorders were assessed. Results: The most common foot posture according to the FPI assessment are the pronated position in the left foot (32.7% of participants) and the neutral position in the right foot (34.1% of participants). The disease progression causes more developed and serious foot deformities. 1.82% of patients present a severe level of Hallux Valgus before 10 years of disease evolution whereas 4.09% of patients present a severe level of Hallux Valgus after 10 years of disease evolution. Conclusions: The most common foot type in patients with RA is the pronated foot type with deformities in the MTP joints without Hallux Valgus. However, a percentage of patients with RA presents supinated foot type. The evolution of the disease shows some morphological changes in terms of patient's feet. The presence of more developed foot deformities is increased, such us Hallux Valgus or MTP joints deformity (Grade 3 in the Nijmegen classification scale).

Effects of Novel Inverted Rocker Orthoses for First Metatarsophalangeal Joint on Gastrocnemius Muscle Electromyographic Activity during Running: A Cross-Sectional Pilot Study.

BACKGROUND: The mobility of the first metatarsophalangeal joint (I MPTJ) has been related to the proper windlass mechanism and the triceps surae during the heel-off phase of running gait; the orthopedic treatment of the I MPTJ restriction has been made with typical Morton extension orthoses (TMEO). Nowadays it is unclear what effects TMEO or the novel inverted rocker orthoses (NIRO) have on the EMG activity of triceps surae during running. OBJECTIVE: To compare the TMEO effects versus NIRO on EMG triceps surae on medialis and lateralis gastrocnemius activity during running. STUDY DESIGN: A cross-sectional pilot study. METHODS: 21 healthy, recreational runners were enrolled in the present research (mean age 31.41 ± 4.33) to run on a treadmill at 9 km/h using aleatory NIRO of 6 mm, NIRO of 8 mm, TMEO of 6 mm, TMEO of 8 mm, and sports shoes only (SO), while the muscular EMG of medial and lateral gastrocnemius activity during 30 s was recorded. Statistical intraclass correlation coefficient (ICC) to test reliability was calculated and the Wilcoxon test of all five different situations were tested. RESULTS: The reliability of values was almost perfect. Data showed that the gastrocnemius lateralis increased its EMG activity between SO vs. NIRO-8 mm (22.27 ± 2.51 vs. 25.96 ± 4.68 mV, p < 0.05) and SO vs. TMEO-6mm (22.27 ± 2.51 vs. 24.72 ± 5.08 mV, p < 0.05). Regarding gastrocnemius medialis, values showed an EMG notable increase in activity between SO vs. NIRO-6mm (22.93 ± 2.1 vs. 26.44 ± 3.63, p < 0.001), vs. NIRO-8mm (28.89 ± 3.6, p < 0.001), and vs. TMEO-6mm (25.12 ± 3.51, p < 0.05). CONCLUSIONS: Both TMEO and NIRO have shown an increased EMG of the lateralis and medialis gastrocnemius muscles activity during a full running cycle gait. Clinicians should take into account the present evidence when they want to treat I MTPJ restriction with orthoses, and consider the inherent triceps surae muscular cost relative to running economy.

RVD induction and autologous stem cell transplantation followed by lenalidomide maintenance in newly diagnosed multiple myeloma: a phase 2 study of the Finnish Myeloma Group.

Autologous stem cell transplantation (ASCT) combined with novel agents is the standard treatment for transplant-eligible, newly diagnosed myeloma (NDMM) patients. Lenalidomide is approved for maintenance after ASCT until progression, although the optimal duration of maintenance is unknown. In this trial, 80 patients with NDMM received three cycles of lenalidomide, bortezomib, and dexamethasone followed by ASCT and lenalidomide maintenance until progression or toxicity. The primary endpoint was the proportion of flow-negative patients. Molecular response was assessed if patients were flow-negative or in stringent complete response (sCR). By intention to treat, the overall response rate was 89%. Neither median progression-free survival nor overall survival (OS) has been reached. The OS at 3 years was 83%. Flow-negativity was reached in 53% and PCR-negativity in 28% of the patients. With a median follow-up of 27 months, 29 (36%) patients are still on lenalidomide and 66% of them have sustained flow-negativity. Lenalidomide maintenance phase was reached in 8/16 high-risk patients but seven of them have progressed after a median of only 6 months. In low- or standard-risk patients, the outcome was promising, but high-risk patients need more effective treatment approach. Flow-negativity with the conventional flow was an independent predictor for longer PFS.

Safety and efficacy of pomalidomide plus low-dose dexamethasone in STRATUS (MM-010): a phase 3b study in refractory multiple myeloma.

Patients with relapsed and/or refractory multiple myeloma (RRMM) have poor prognosis. The STRATUS study assessed safety and efficacy of pomalidomide plus low-dose dexamethasone in the largest cohort to date of patients with RRMM. Patients who failed treatment with bortezomib and lenalidomide and had adequate prior alkylator therapy were eligible. Pomalidomide 4 mg was given on days 1-21 of 28-day cycles with low-dose dexamethasone 40 mg (20 mg for patients aged >75 years) on days 1, 8, 15, and 22 until progressive disease or unacceptable toxicity. Safety was the primary end point; secondary end points included overall response rate (ORR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Among 682 patients enrolled, median age was 66 years, and median time since diagnosis was 5.3 years. Median number of prior regimens was 5. Most patients were refractory to both lenalidomide and bortezomib (80.2%). Median follow-up was 16.8 months; median duration of treatment was 4.9 months. Most frequent grade 3/4 treatment-emergent adverse events were hematologic (neutropenia [49.7%], anemia [33.0%], and thrombocytopenia [24.1%]). Most common grade 3/4 nonhematologic toxicities were pneumonia (10.9%) and fatigue (5.9%). Grade 3/4 venous thromboembolism and peripheral neuropathy were rare (1.6% each). The ORR was 32.6%, and the median DOR was 7.4 months. Median PFS and OS were 4.6 months and 11.9 months, respectively. We present the largest trial to date evaluating pomalidomide plus low-dose dexamethasone in patients with RRMM, further confirming that this regimen offers clinically meaningful benefit and is generally well tolerated. www.Clinicaltrials.gov identifier NCT01712789.

Adverse event management in patients with relapsed and refractory multiple myeloma taking pomalidomide plus low-dose dexamethasone: A pooled analysis.

OBJECTIVES: Heavily pretreated patients with relapsed and refractory multiple myeloma are susceptible to treatment-related adverse events (AEs). Managing AEs are important to ensure patients continue therapy long enough to receive the best clinical benefit. Data from the MM-002, MM-003, and MM-010 trials were pooled to further characterize the safety profile of pomalidomide plus low-dose dexamethasone and AE management. METHODS: This analysis included 1088 patients who received ≥ 2 prior therapies, including lenalidomide and bortezomib, and progressed ≤ 60 days of last therapy. Patients received 28-day cycles of pomalidomide 4 mg/day on days 1-21 and low-dose dexamethasone 40 mg (20 mg if aged > 75 years) weekly until disease progression or unacceptable toxicity. Thromboprophylaxis was required. RESULTS: The most common grade 3/4 AEs were neutropenia (56.2%), anemia (32.3%), and thrombocytopenia (25.8%), which occurred within the first few cycles of treatment. Grade 3/4 infections occurred in 33.7% patients, of whom 13.9% had pneumonia, and 40.3% had neutropenia. Pomalidomide dose reductions or interruptions were reported in 24.2% and 66.0% of patients, respectively. AEs were managed by dose modifications and/or supportive care. CONCLUSIONS: Pomalidomide plus low-dose dexamethasone showed an acceptable safety profile, and AEs were well managed according to study protocols and established guidelines.

Cost analysis of a randomized stem cell mobilization study in multiple myeloma.

Upfront autologous stem cell transplantation (ASCT) is the standard therapy for younger multiple myeloma (MM) patients. MM patients usually undergo stem cell mobilization with cyclophosphamide (CY) followed by granulocyte colony-stimulating factor (G-CSF), or with G-CSF alone. A limited number of randomized studies are available comparing costs of different mobilization strategies. Eighty transplant-eligible patients aged up to 70 years with untreated MM were included in this prospective study. The patients were treated with RVD induction for three 21-day cycles and randomized 1:1 at inclusion into one of the two mobilization arms CY 2 g/m(2) + G-CSF [arm A] vs. G-CSF alone [arm B]. Plerixafor was given according to a specific algorithm if needed. Sixty-nine patients who received mobilization followed by blood graft collection were included in the cost analysis. The median total costs of the mobilization phase were significantly higher in arm A than in arm B (3855 € vs. 772 €, p ≤ 0.001). The cumulative median cost of the mobilization and collection phases was significantly lower in arm B than in arm A (8524 € vs. 11,622 €, p = 0.012). There was no significant difference between the arms in the total median costs of ASCT (n = 59) (34,997 € in arm A vs. 31,981 € in arm B, p = 0.118). Mobilization with G-CSF alone seems to be a preferable mobilization method for MM patients in terms of mobilization and apheresis costs. In addition, it requires less hospital resource utilization.

[Hereditary macrothrombocytopenia and hearing loss]. / Perinnöllinen makrotrombosytopenia ja kuulovika.

We describe an autosomal dominant hereditary thrombocytopenia syndrome caused by a defect in the MYH9 gene. Of our three patients, all have thrombocytopenia from birth, and their thrombocytes are large in size. The hemorrhagic tendency caused by thrombocytopenia is often mild. Approximately 60% of the patients develop sensorineural hearing loss and approx. 30% develop renal insufficiency that frequently progresses to require hemodialysis. It is of particular importance to recognize the thrombocytopenia as being hereditary and permanent in order to save the patients from useless and harmful therapeutic efforts.

Real-world treatment patterns and outcomes for patients with multiple myeloma in Denmark, Finland and Sweden: An analysis using linked Nordic registries.

AIM: The Health outcomes and Understanding of MyelomA multi-National Study (HUMANS) was a large-scale, retrospective study conducted across Denmark, Finland and Sweden using linked data from national registries. We describe the characteristics, treatment patterns and clinical outcomes for patients with newly diagnosed multiple myeloma (NDMM) over 2010-2018. METHODS: Patients with NDMM who received MM-specific, first-line treatments, were categorised by treatment (autologous stem cell transplantation [ASCT] or a combination chemotherapy regimen based on bortezomib, lenalidomide or melphalan-prednisolone-thalidomide). RESULTS: 11,023 patients received treatment over 2010-2018. Time between diagnosis and treatment was shortest in Denmark (0.9 months), then Sweden (2.9 months) and Finland (4.6 months). Around one third of patients underwent ASCT. Lenalidomide-based regimens were prescribed to 23-28% of patients in Denmark and Finland, versus 12% in Sweden. Patients receiving lenalidomide had the longest wait for treatment, from 3.2 months (Denmark) to 12.1 months (Sweden). Treatment persistence was highest among patients receiving melphalan-prednisolone-thalidomide (7-8 months) in Finland and Sweden and lowest among those receiving bortezomib (3.5 months) in Finland. Overall survival (OS) was longest among patients with ASCT (7-10 years). Among patients receiving chemotherapy, OS (from diagnosis/treatment initiation), varied between cohorts. In a sensitivity analysis excluding patients with smouldering MM, OS decreased for all; for patients receiving bortezomib or lenalidomide, OS from diagnosis was 40-49 and 27-54 months, respectively. CONCLUSIONS: This population-based study of patients with NDMM receiving first-line MM-specific treatment, provides real-world data on treatment patterns and outcomes to complement data from randomised clinical trials.

Ixazomib, Lenalidomide, and Dexamethasone (IRD) Treatment with Cytogenetic Risk-Based Maintenance in Transplant-Eligible Myeloma: A Phase 2 Multicenter Study by the Nordic Myeloma Study Group.

Scarce data exist on double maintenance in transplant-eligible high-risk (HR) newly diagnosed multiple myeloma (NDMM) patients. This prospective phase 2 study enrolled 120 transplant-eligible NDMM patients. The treatment consisted of four cycles of ixazomib-lenalidomide-dexamethasone (IRD) induction plus autologous stem cell transplantation followed by IRD consolidation and cytogenetic risk-based maintenance therapy with lenalidomide + ixazomib (IR) for HR patients and lenalidomide (R) alone for NHR patients. The main endpoint of the study was undetectable minimal residual disease (MRD) with sensitivity of <10-5 by flow cytometry at any time, and other endpoints were progression-free survival (PFS) and overall survival (OS). We present the preplanned analysis after the last patient has been two years on maintenance. At any time during protocol treatment, 28% (34/120) had MRD < 10-5 at least once. At two years on maintenance, 66% of the patients in the HR group and 76% in the NHR group were progression-free (p = 0.395) and 36% (43/120) were CR or better, of which 42% (18/43) had undetectable flow MRD <10-5. Altogether 95% of the patients with sustained MRD <10-5, 82% of the patients who turned MRD-positive, and 61% of those with positive MRD had no disease progression at two years on maintenance (p < 0.001). To conclude, prolonged maintenance with all-oral ixazomib plus lenalidomide might improve PFS in HR patients.

Use of Linked Nordic Registries for Population Studies in Hematologic Cancers: The Case of Multiple Myeloma.

Purpose: Linked health-care registries and high coverage in Nordic countries lend themselves well to epidemiologic research. Given its relatively high incidence in Western Europe, complexity in diagnosis, and challenges in registration, multiple myeloma (MM) was selected to compare registries in Denmark, Finland, and Sweden. Patients and Methods: Data were obtained from four archetypal registries in each country (spanning January 2005-October 2018): National Patient Registry (NPR), Prescribed Drug Registry (PDR), Cancer Registry (CR), and Cause of Death Registry. Patients newly diagnosed with MM who received MM-specific treatment were included. PDR/NPR treatment records were used to assess incident NPR cases. The registration quality of MM-specific drugs in the PDR of each country was also evaluated. Results: In Denmark, only 6% of patients in the NPR were not registered in the CR; in Sweden, it was 16.9%. No systematic differences were identified that could explain this discrepancy. In Denmark, lenalidomide and bortezomib were registered in the NPR with high coverage, but less expensive drugs typically given in combination with bortezomib were not covered in any of the registries. In Finland and Sweden, bortezomib records were not identified in the PDR, but some were in the NPR; other drugs had good coverage in the PDR. Conclusions: The registries evaluated in this study can be used to identify the MM population; however, given the gaps in MM registration in the Finnish and Swedish CRs, Danish registries provide the most comprehensive datasets for research on treatment patterns for MM.

Deep Immune Profiling of Multiple Myeloma at Diagnosis and under Lenalidomide Maintenance Therapy.

The bone marrow microenvironment interacts with malignant cells and regulates cancer survival and immune evasion in multiple myeloma (MM). We investigated the immune profiles of longitudinal bone marrow samples from patients with newly diagnosed MM (n = 18) using cytometry by time-of-flight. The results before and during treatment were compared between patients with good (GR, n = 11) and bad (BR, n = 7) responses to lenalidomide/bortezomib/dexamethasone-based treatment. Before treatment, the GR group had a lower tumor cell burden and a higher number of T cells with a phenotype shifted toward CD8+ T cells expressing markers attributed to cytotoxicity (CD45RA and CD57), a higher abundance of CD8+ terminal effector cells, and a lower abundance of CD8+ naïve T cells. On natural killer (NK) cells, increased expression of CD56 (NCAM), CD57, and CD16 was seen at baseline in the GR group, indicating their maturation and cytotoxic potential. During lenalidomide-based treatment, the GR patients showed an increase in effector memory CD4+ and CD8+ T-cell subsets. These findings support distinct immune patterns in different clinical contexts, suggesting that deep immune profiling could be used for treatment guidance and warrants further exploration.

[Diabetic microangiopathic hemolytic anemia--rare complication of a common disease]. / Diabeettinen mikroangiopaattinen hemolyyttinen anemia--tavallisen taudin harvinainen komplikaatio.

It is well-known that long-standing diabetes damages the vasculature. It is less frequently known that the plasticity of red blood cells may also be impaired so that they do not always survive intact in a vasculature roughened by diabetes, but are instead lysed. Lysis of red blood cells results in fragmentation hemolysis, which may lead to anemia if formation of red blood cells is deficient. We describe two patients with this rare complication, both of whom were diagnosed with diabetic microangiopathic hemolytic anemia (DMHA) during pregnancy.

[Thirst and extensive bone lesions in a previously basically healthy woman]. / Aiemmin terveen naisen jano ja laaja-alaiset luustomuutokset.

A previously quite healthy 65-year-old woman sought emergency hospital care due to fatigue, weight loss and sensation of thirst appearing over a couple of months. Further analysis revealed a process affecting the neurohypophysis and extensive lytic sclerotic bone lesions. Eventually a rare generalized underlying disease was unraveled: the diagnosis included both Langerhans cell histiocytosis and Erdheim-Chester disease.

A germline exome analysis reveals harmful POT1 variants in multiple myeloma patients and families.

Observations of inherited susceptibility to multiple myeloma have led to active research in defining predisposing genes to the disease. Here, we analysed 128 plasma cell dyscrasia patients' germline whole-exome sequencing data. Rare dominantly inherited pathogenic or likely pathogenic (P/LP) variant was found in 9.4% of the patients. Among the P/LP variants, CHEK2 (p. Thr410MetfsTer15) was the most prevalent (n = 5, 3.9%). Interestingly, P/LP variants in POT1 were identified in three patients (2.3%). Our findings broaden the spectrum of POT1-related cancers and demonstrate the importance of the germline genetic analysis in hematological malignancies.

Next generation proteomics with drug sensitivity screening identifies sub-clones informing therapeutic and drug development strategies for multiple myeloma patients.

With the introduction of novel therapeutic agents, survival in Multiple Myeloma (MM) has increased in recent years. However, drug-resistant clones inevitably arise and lead to disease progression and death. The current International Myeloma Working Group response criteria are broad and make it difficult to clearly designate resistant and responsive patients thereby hampering proteo-genomic analysis for informative biomarkers for sensitivity. In this proof-of-concept study we addressed these challenges by combining an ex-vivo drug sensitivity testing platform with state-of-the-art proteomics analysis. 35 CD138-purified MM samples were taken from patients with newly diagnosed or relapsed MM and exposed to therapeutic agents from five therapeutic drug classes including Bortezomib, Quizinostat, Lenalidomide, Navitoclax and PF-04691502. Comparative proteomic analysis using liquid chromatography-mass spectrometry objectively determined the most and least sensitive patient groups. Using this approach several proteins of biological significance were identified in each drug class. In three of the five classes focal adhesion-related proteins predicted low sensitivity, suggesting that targeting this pathway could modulate cell adhesion mediated drug resistance. Using Receiver Operating Characteristic curve analysis, strong predictive power for the specificity and sensitivity of these potential biomarkers was identified. This approach has the potential to yield predictive theranostic protein panels that can inform therapeutic decision making.

Aminopeptidase Expression in Multiple Myeloma Associates with Disease Progression and Sensitivity to Melflufen.

Multiple myeloma (MM) is characterized by extensive immunoglobulin production leading to an excessive load on protein homeostasis in tumor cells. Aminopeptidases contribute to proteolysis by catalyzing the hydrolysis of amino acids from proteins or peptides and function downstream of the ubiquitin-proteasome pathway. Notably, aminopeptidases can be utilized in the delivery of antibody and peptide-conjugated drugs, such as melflufen, currently in clinical trials. We analyzed the expression of 39 aminopeptidase genes in MM samples from 122 patients treated at Finnish cancer centers and 892 patients from the CoMMpass database. Based on ranked abundance, LAP3, ERAP2, METAP2, TTP2, and DPP7 were highly expressed in MM. ERAP2, XPNPEP1, DPP3, RNPEP, and CTSV were differentially expressed between relapsed/refractory and newly diagnosed MM samples (p < 0.05). Sensitivity to melflufen was detected ex vivo in 11/15 MM patient samples, and high sensitivity was observed, especially in relapsed/refractory samples. Survival analysis revealed that high expression of XPNPEP1, RNPEP, DPP3, and BLMH (p < 0.05) was associated with shorter overall survival. Hydrolysis analysis demonstrated that melflufen is a substrate for aminopeptidases LAP3, LTA4H, RNPEP, and ANPEP. The sensitivity of MM cell lines to melflufen was reduced by aminopeptidase inhibitors. These results indicate critical roles of aminopeptidases in disease progression and the activity of melflufen in MM.