Changes in T-cell subsets, preexisting cytopenias and hyperferritinaemia correlate with cytopenias after BCMA targeted CAR T-cell therapy in relapsed/refractory multiple myeloma: Results from a prospective comprehensive biomarker study.

Biomarkers for cytopenias following CAR T-cell treatment in relapsed/refractory (RR) multiple myeloma (MM) are not completely defined. We prospectively analysed 275 sequential peripheral blood (PB) samples from 58 RRMM patients treated with BCMA-targeted CAR T cells, and then divided them into three groups: (i) baseline (before leukapheresis), (ii) ≤day+30, and (iii) >day+30 after CAR T-cell therapy. We evaluated laboratory data and performed flow cytometry to determine the (CAR) T-cell subsets. Baseline hyperferritinaemia was a risk factor for long-lasting grade ≥3 anaemia (r = 0.47, p < 0.001) and thrombocytopenia (r = 0.44, p = 0.002) after CAR T-cell therapy. Low baseline haemoglobin (Hb) and PLT were associated with long-lasting grade ≥3 anaemia (r = -0.56, p < 0.001) and thrombocytopenia (r = -0.44, p = 0.002) respectively. We observed dynamics of CAR-negative T-cell subsets following CAR T-cell infusion. In the late phase after CAR T-cell therapy (>day+30), CD4Tn frequency correlated with anaemia (r = 0.41, p = 0.0014) and lymphocytopenia was related to frequencies of CD8+ T cells (r = 0.72, p < 0.001) and CD8Teff (r = 0.64, p < 0.001). CD4Tcm frequency was correlated with leucocytopenia (r = -0.49, p < 0.001). In summary, preexisting cytopenias and hyperferritinaemia indicated long duration of grade ≥3 post-CAR T-cell cytopenias. Prolonged cytopenia may be related to immune remodelling with a shift in the CAR-negative T-cell subsets following CAR T-cell therapy.

Daratumumab in first-line treatment of patients with light chain amyloidosis and Mayo stage IIIb improves treatment response and overall survival.

Treatment of patients with Mayo stage IIIb light chain (AL) amyloidosis is still challenging, and the prognosis remains very poor. Mayo stage IIIb patients were excluded from the pivotal trial leading to the approval of daratumumab in combination with bortezomib-cyclophosphamide-dexamethasone. This retrospective, multicenter study evaluates the addition of daratumumab to first-line therapy in patients with newly diagnosed stage IIIb AL amyloidosis. In total, data from 119 consecutive patients were analyzed, 27 patients received an upfront treatment including daratumumab, 63 a bortezomibbased regimen without daratumumab, eight received therapies other than daratumumab or bortezomib and 21 pretreated patients or deceased prior to treatment were excluded. In the daratumumab group, median overall survival was not reached after a median follow-up time of 14.5 months, while it was significantly worse in the bortezomib- and the otherwise treated group (6.6 and 2.2 months, respectively) (P=0.002). Overall hematologic response rate at 2 and 6 months was better in the daratumumab group compared to the bortezomib group (59% vs. 37%, P=0.12, 67% vs. 41%, P=0.04, respectively). Landmark survival analyses revealed a significantly improved overall survival in patients with partial hematologic response or better, compared to non-responders. Cardiac response at 6 months was 46%, 21%, 0% in the daratumumab-, bortezomib- and otherwise treated groups, respectively (P=0.04). A landmark survival analysis revealed markedly improved overall survival in patients with cardiac very good partial response vs. cardiac non-responders (P=0.002). This study demonstrates for the first time the superiority of an upfront treatment with daratumumab over standard-of-care in stage IIIb AL amyloidosis.

Soluble B-cell maturation antigen in lacrimal fluid as a potential biomarker and mediator of keratopathy in multiple myeloma.

Belantamab mafodotin (belantamab) is a first-in-class anti-BCMA antibody-drug conjugate approved for the treatment of triple-class refractory multiple myeloma. It provides a unique therapeutic option for patients ineligible for CAR-T and bispecific antibody therapy, and/or patients progressing on anti-CD38 treatment where CAR-T and bispecifics might be kept in reserve. Wider use of the drug can be challenged by its distinct ocular side effect profile, including corneal microcysts and keratopathy. While dose reduction has been the most effective way to reduce these toxicities, the underlying mechanism of this BCMA off-target effect remains to be characterized. In this study, we provide the first evidence for soluble BCMA (sBCMA) in lacrimal fluid and report on its correlation with tumor burden in myeloma patients. We confirm that corneal cells do not express BCMA, and show that sBCMA-belantamab complexes may rather be internalized by corneal epithelial cells through receptor-ligand independent pinocytosis. Using an hTcEpi corneal cell-line model, we show that the pinocytosis inhibitor EIPA significantly reduces belantamab-specific cell killing. As a proof of concept, we provide detailed patient profiles demonstrating that, after belantamab-induced cell killing, sBCMA is released into circulation, followed by a delayed increase of sBCMA in the tear fluid and subsequent onset of keratopathy. Based on the proposed mechanism, pinocytosis-induced keratopathy can be prevented by lowering the entry of sBCMA into the lacrimal fluid. Future therapeutic concepts may therefore consist of belantamab-free debulking therapy prior to belantamab consolidation and/or concomitant use of gamma-secretase inhibition as currently evaluated for belantamab and nirogacestat in ongoing studies.

High-dose carfilzomib achieves superior anti-tumor activity over low-dose and recaptures response in relapsed/refractory multiple myeloma resistant to lowdose carfilzomib by co-inhibiting the ß2 and ß1 subunits of the proteasome complex.

Optimal carfilzomib dosing is a matter of debate. We analyzed the inhibition profiles of proteolytic proteasome subunits ß5, ß2 and ß1 after low-dose (20/27 mg/m2) versus high-dose (≥36 mg/m2) carfilzomib in 103 pairs of peripheral blood mononuclear cells from patients with relapsed/refractory (RR) multiple myeloma (MM). ß5 activity was inhibited (median inhibition >50%) in vivo by 20 mg/m2, whereas ß2 and ß1 were co-inhibited only by 36 and 56 mg/m2, respectively. Coinhibition of ß2 (P=0.0001) and ß1 activity (P=0.0005) differed significantly between high-dose and low-dose carfilzomib. Subsequently, high-dose carfilzomib showed significantly more effective proteasome inhibition than low-dose carfilzomib in vivo (P=0.0003). We investigated the clinical data of 114 patients treated with carfilzomib combinations. High-dose carfilzomib demonstrated a higher overall response rate (P=0.03) and longer progression-free survival (PFS) (P=0.007) than low-dose carfilzomib. Therefore, we escalated the carfilzomib dose to ≥36 mg/m2 in 16 patients who progressed during low-dose carfilzomib-containing therapies. High-dose carfilzomib recaptured response (≥ partial remission) in nine (56%) patients with a median PFS of 4.4 months. Altogether, we provide the first in vivo evidence in RRMM patients that the molecular activity of high-dose carfilzomib differs from that of low-dose carfilzomib by coinhibition of ß2 and ß1 proteasome subunits and, consequently, high-dose carfilzomib achieves a superior anti-MM effect than low-dose carfilzomib and recaptures the response in RRMM resistant to low-dose carfilzomib. The optimal carfilzomib dose should be ≥36 mg/m2 to reach a sufficient anti-tumor activity, while the balance between efficacy and tolerability should be considered in each patient.

Minimal residual disease and imaging-guided consolidation strategies in newly diagnosed and relapsed refractory multiple myeloma.

Measurement of minimal residual disease (MRD) by next-generation flow cytometry (NGF) is an important tool to define deep responses in multiple myeloma (MM). However, little is known about the value of combining NGF with functional imaging and its role for MRD-based consolidation strategies in clinical routine. In the present study, we report our experience investigating these issues with 102 patients with newly diagnosed (n = 57) and relapsed/refractory MM (n = 45). Imaging was performed using either positron emission tomography or diffusion-weighted magnetic resonance imaging. In all, 45% of patients achieved MRD-negativity on both NGF and imaging (double-negativity), and 8% and 40% of patients were negative on either NGF or imaging respectively. Thus, in a minority of patients imaging was the only technique to detect residual disease. Imaging-positivity despite negativity on NGF was more common in heavily pretreated disease (four or more previous lines) compared to newly diagnosed MM (p < 0.01). Among the 29 patients undergoing MRD-triggered consolidation, 51% responded with MRD conversion and 21% with improved serological response. MRD-triggered consolidation led to superior progression-free survival (PFS) when compared to standard treatment (p = 0.04). In conclusion, we show that combining NGF with imaging is helpful particularly in patients with heavily pretreated MM, and that MRD-based consolidation could lead to improved PFS.

Salvage therapy with "Dara-KDT-P(A)CE" in heavily pretreated, high-risk, proliferative, relapsed/refractory multiple myeloma.

The multi-agent therapy "VDT-PACE" represents an established regimen in relapsed/refractory multiple myeloma (RRMM). Here, we report on our experience with a "modified VDT-PACE" incorporating new generation anti-MM agents daratumumab and carfilzomib ("Dara-KDT-P(A)CE"). We retrospectively analyzed 38 patients with RRMM treated with "Dara-KDT-P(A)CE". The median age was 62 (range 45-82) years, and the patients were heavily pretreated with a median of 5 (range 2-12) prior lines of therapy. Twenty-one (55%) patients suffered from penta-refractory MM. High-risk cytogenetics was present in 31 (81%) patients. The patients received a median of 2 (range 1-10) cycles of this therapy, and the overall response rate (ORR) was 70%. Patients with penta-refractory MM and high-risk cytogenetics showed similar ORR of 65% and 79%, respectively. The median progression-free survival (PFS) and overall survival were 4.1 (95% CI 2.7-5.4) and 8.4 (95% CI 6.7-10.0) months, respectively. Patients with lactate dehydrogenase >250 IU/L showed significantly shorter PFS in comparison with others patients (p = 0.006). We used this regimen as bridging therapy prior to chimeric antigen receptor T-cell infusion in four patients. In conclusion, "Dara-KDT-P(A)CE" is an effective salvage therapy for patients with heavily pretreated, multi-refractory, high-risk RRMM lacking alternative options.

Obinutuzumab and venetoclax induced complete remission in a patient with ibrutinib-resistant non-nodal leukemic mantle cell lymphoma.

We herein report the case of a 73-year-old male patient who was diagnosed with leukemic non-nodal MCL. This patient had received six cycles of bendamustine, which resulted in a transient remission, and a second-line therapy with ibrutinib, which unfortunately failed to induce remission. We started a treatment with single-agent obinutuzumab at a dose of 20 mg on day 1, 50 mg on day 2-4, 330 mg on day 5, and 1000 mg on day 6. The laboratory analysis showed a rapid decrease of leukocyte count. Four weeks later, we repeated the treatment with obinutuzumab at a dose of 1000 mg q4w and started a therapy with venetoclax at a dose of 400 mg qd, which could be increased to 800 mg qd from the third cycle. This combination therapy was well tolerated. The patient achieved a complete remission (CR) after three cycles of obinutuzumab and venetoclax. To date, the patient has a progression-free survival of 17 months under ongoing obinutuzumab maintenance q4w. This is the first report about obinutuzumab and venetoclax induced CR in rituximab-intolerant patient with an ibrutinib-resistant MCL. This case suggests that obinutuzumab- and venetoclax-based combination therapy might be salvage therapy in patients with ibrutinib-resistant MCL.

Incremental prognostic utility of congestion markers in cardiac transthyretin amyloidosis.

BACKGROUND/AIMS: Congestion is prognostically relevant in cardiac transthyretin amyloidosis (ATTR-CA), but whether congestion has an incremental prognostic value beyond the well-established, congestion-sensitive NT-proBNP is unknown. Therefore, we aimed to comparatively evaluate the prognostic utility of several congestion surrogates over NT-proBNP. METHODS: We estimated hazard ratios by Cox proportional hazards regressions with time-varying covariates from a panel data set of the local amyloidosis cohort study AmyKoS. Different models were compared by using chi(χ)2-statistics measuring overall model significance. RESULTS/CONCLUSION: 131 ATTR-CA patients (wild-type 84.0%, hereditary 6.9%, without genetic testing 9.2%; median age 78.7 (quartiles 73.3, 82.1) years; 85.5% male) with 566 observations across a median follow-up of 38.2 (30.6; 48.2) months were analyzed. 83.2% received disease-modifying treatment; 20.6% participated concurrently in placebo-controlled gene silencer trials. Information on congestion improved biomarker-driven risk stratification and identified patients at the highest risk. Echocardiographic congestion markers performed better than clinical findings and daily diuretic use/dosage. Relevant adjusters were daily diuretic dosage, disease-modifying treatment, eGFR, and right atrial volume. NT-proBNP and the tricuspid regurgitation peak velocity (tr-vmax) provided an easy-to-use stratification with overall model performance similar to NAC and Mayo staging systems. Further analyses are necessary for validation and to identify the optimal cut points of the congestion markers.

Safety and Tolerability of SGLT2 Inhibitors in Cardiac Amyloidosis-A Clinical Feasibility Study.

Sodium-glucose transport protein 2 inhibitors (SGLT2i) slow the progression of renal dysfunction and improve the prognosis of patients with heart failure. Amyloidosis constitutes an important subgroup for which evidence is lacking. Amyloidotic fibrils originating from misfolded transthyretin and light chains are the causal agents in ATTR and AL amyloidosis. In these most frequent subtypes, cardiac involvement is the most common organ manifestation. Because cardiac and renal function frequently deteriorate over time, even under best available treatment, SGLT2i emerge as a promising treatment option due to their reno- and cardioprotective properties. We retrospectively analyzed patients with cardiac amyloidosis, who received either dapagliflozin or empagliflozin. Out of 79 patients, 5.1% had urinary tract infections; 2 stopped SGLT2i therapy; and 2.5% died unrelated to the intake of SGLT2i. No genital mycotic infections were observed. As expected, a slight drop in the glomerular filtration rate was noted, while the NYHA functional status, cardiac and hepatic function, as well as the 6 min walk distance remained stable over time. These data provide a rationale for the use of SGLT2i in patients with amyloidosis and concomitant cardiac or renal dysfunction. Prospective randomized data are desired to confirm safety and to prove efficacy in this increasingly important group of patients.

Outcomes of Modified Mayo Stage IIIa and IIIb Cardiac Light-Chain Amyloidosis: Real-World Experience in Clinical Characteristics and Treatment-67 Patients Multicenter Analysis.

Light-chain amyloidosis (AL) is a rare multisystem disorder characterized by the deposition of misfolded amyloid fibrils derived from monoclonal immunoglobulin light chains in various organs. One of the most common organs involved in AL is the heart, with 50-70% of patients clinically symptomatic at diagnosis. We conducted a multi-center, retrospective analysis of 67 patients diagnosed between July 2012 and August 2022 with the European 2012 modification of Mayo 2004 stage III cardiac AL. The most important factors identified in the univariate Cox analysis contributing to a longer OS included Eastern Cooperative Oncology Group performance status (ECOG PS) ≤ 1, New York Heart Association functional classification (NYHA FC) ≤ 2, the use of autologous stem cell transplantation (ASCT) after induction treatment, achieving a hematological response (≥very good partial response) and cardiac (≥partial response) response after first-line treatment. The most important prognostic factors with the most significant impact on OS improvement in patients with modified Mayo stage III cardiac AL identified by multivariate Cox analysis are ECOG PS ≤ 1, NYHA FC ≤ 2, and achieving hematological response ≥ VGPR and cardiac response ≥ PR after first-line treatment.

Fibroblast KATP currents modulate myocyte electrophysiology in infarcted hearts.

Cardiac metabolism remains altered for an extended period of time after myocardial infarction. Studies have shown fibroblasts from normal hearts express KATP channels in culture. It is unknown whether fibroblasts from infarcted hearts express KATP channels and whether these channels contribute to scar and border zone electrophysiology. KATP channel subunit expression levels were determined in fibroblasts isolated from normal hearts (Fb), and scar (sMI-Fb) and remote (rMI-Fb) regions of left anterior descending coronary artery (LAD) ligated rat hearts. Whole cell KATP current density was determined with patch clamp. Action potential duration (APD) was measured with optical mapping in myocyte-only cultures and heterocellular cultures with fibroblasts with and without 100 µmol/l pinacidil. Whole heart optical mapping was used to assess KATP channel activity following LAD ligation. Pinacidil activated a potassium current (35.4 ± 7.5 pA/pF at 50 mV) in sMI-Fb that was inhibited with 10 µmol/l glibenclamide. Kir6.2 and SUR2 transcript levels were elevated in sMI-Fb. Treatment with Kir6.2 short interfering RNA decreased KATP currents (87%) in sMI-Fb. Treatment with pinacidil decreased APD (26%) in co-cultures with sMI-Fb. APD values were prolonged in LAD ligated hearts after perfusion with glibenclamide. KATP channels are present in fibroblasts from the scar and border zones of infarcted hearts. Activation of fibroblast KATP channels could modulate the electrophysiological substrate beyond the acute ischemic event. Targeting fibroblast KATP channels could represent a novel therapeutic approach to modify border zone electrophysiology after cardiac injury.

Single-Nucleotide Variants and Epimutations Induce Proteasome Inhibitor Resistance in Multiple Myeloma.

PURPOSE: Proteasome inhibitors (PI) are the backbone of various treatment regimens in multiple myeloma. We recently described the first in-patient point mutations affecting the 20S subunit PSMB5 underlying PI resistance. Notably, in vivo, the incidence of mutations in PSMB5 and other proteasome encoding genes is too low to explain the development of resistance in most of the affected patients. Thus, additional genetic and epigenetic alterations need to be explored. EXPERIMENTAL DESIGN: We performed DNA methylation profiling by Deep Bisulfite Sequencing in PSMB5, PSMC2, PSMC5, PSMC6, PSMD1, and PSMD5, a subset of proteasome subunits that have hitherto been associated with PI resistance, recruited from our own previous research, the literature, or a meta-analysis on the frequency of somatic mutations. Methylation was followed up on gene expression level and by dual-luciferase reporter assay. The KMS11 cell line served as a model to functionally test the impact of demethylating agents. RESULTS: We identified PSMD5 promoter hypermethylation and subsequent epigenetic gene silencing in 24% of PI refractory patients. Hypermethylation correlated with decreased expression and the regulatory impact of this region was functionally confirmed. In contrast, patients with newly diagnosed multiple myeloma, along with peripheral blood mononuclear cells and CD138+ plasma cells from healthy donors, generally show unmethylated profiles. CONCLUSIONS: Under the selective pressure of PI treatment, multiple myeloma cells acquire methylation of the PSMD5 promoter silencing the PSMD5 gene expression. PSMD5 acts as a key orchestrator of proteasome assembly and its downregulation was described to increase the cell's proteolytic capacity. PSMD5 hypermethylation, therefore, represents a novel mechanism of PI tolerance in multiple myeloma.

Bortezomib induced peripheral neuropathy and single nucleotide polymorphisms in PKNOX1.

We analyzed single nucleotide polymorphisms (SNPs) in PKNOX1 (rs2839629) and in the intergenic region between PKNOX1 and CBS (rs915854) by Sanger sequencing in 88 patients with multiple myeloma treated with bortezomib. All patients (n = 13) harboring a homozygous mutation in PKNOX1 (rs2839629) also had a homozygous mutated rs915854 genotype. Homozygous mutated genotypes of rs2839629 and rs915854 were significantly enriched in patients with painful peripheral neuropathy (PNP) (P < 0.0001), and homozygous mutated rs2839629 genotype was significantly enriched in patients with pain compared to patients with no pain (P = 0.04). In summary, both SNPs rs2839629 and/or rs915854 may be potential biomarkers predicting an increased risk to develop painful PNP under bortezomib.

Impaired FADD/BID signaling mediates cross-resistance to immunotherapy in Multiple Myeloma.

The treatment landscape in multiple myeloma (MM) is shifting from genotoxic drugs to immunotherapies. Monoclonal antibodies, immunoconjugates, T-cell engaging antibodies and CART cells have been incorporated into routine treatment algorithms, resulting in improved response rates. Nevertheless, patients continue to relapse and the underlying mechanisms of resistance remain poorly understood. While Impaired death receptor signaling has been reported to mediate resistance to CART in acute lymphoblastic leukemia, this mechanism yet remains to be elucidated in context of novel immunotherapies for MM. Here, we describe impaired death receptor signaling as a novel mechanism of resistance to T-cell mediated immunotherapies in MM. This resistance seems exclusive to novel immunotherapies while sensitivity to conventional anti-tumor therapies being preserved in vitro. As a proof of concept, we present a confirmatory clinical case indicating that the FADD/BID axis is required for meaningful responses to novel immunotherapies thus we report impaired death receptor signaling as a novel resistance mechanism to T-cell mediated immunotherapy in MM.

[Monoclonal gammopathy of (un)known significance]. / Die monoklonale Gammopathie (un)klarer Signifikanz.

Monoclonal gammopathies are a frequently diagnosed entity. However, the diagnosis is not always clinically relevant. The diagnosis of a monoclonal gammopathy requires serum electrophoresis, immunofixation and free light chain measurement. Sometimes, monoclonal gammopathies occur in the course of transient or autoimmune inflammation. Further diagnostics should only be performed after risk assessment according to Mayo criteria. In non-low risk patients, a symptomatic myeloma has to be ruled out via SLiM-CRAB criteria. The diagnostic work-up should include whole-body MRI and a bone marrow puncture as well as a 24 h urine sample. If it does not imply myeloma, the diagnosis of MGUS is confirmed and a follow-up after 6 months is recommended. After that, low-risk patients only need SLiM-CRAB screening at clinical signs of progression. All other patients should receive serologic follow-ups once a year. Importantly, MGUS patients show higher morbidity. Amongst a higher prevalence of osteoporosis and immunodeficiency, a wide array of MGUS-associated diseases such as AL amyloidosis, deposition diseases and Fc binding-dependent effects can occur. This article gives an overview over the work-up, observation and caveats of monoclonal gammopathy of (un)known significance.

[Cardiac amyloidosis - important differential diagnosis in heart failure]. / Kardiale Amyloidose ­ wichtige Differenzialdiagnose bei Herzinsuffizienz.

The systemic disease amyloidosis is caused by deposits of misfolded proteins and can cause very different symptoms depending on the organ involvement. The two most common forms are AL amyloidosis and ATTR amyloidosis. The determination of light chains and bone scintigraphy have a high priority in the diagnostic algorithm. New, causally effective substance classes are available for the therapy of AL and ATTR amyloidosis. The classic heart failure medication is often not well tolerated by patients with cardiac amyloidosis and must be adjusted in the presence of symptoms. This article shows which findings and symptom complexes should make you think of amyloidosis and how to arrive at the correct diagnosis in a targeted manner. Causal therapy options as well as special features of heart failure therapy in this patient collective are explained.

R-CHOP intensification with mid-cycle methotrexate and consolidating AraC/TT with BCNU/aHSCT in primary aggressive lymphoma with CNS involvement.

PURPOSE: Patients suffering from aggressive systemic peripheral lymphoma with primary central nervous system involvement (PCL) are a rare and sparsely investigated population. Recommended treatment regimens include a combination of intrathecal and systemic chemotherapy as well as whole brain radiotherapy while offering relatively poor survival. METHODS: We conducted a single-center retrospective study that analyzed safety and outcome of 4 + 4 cycles Rituximab (R)-CHOP and R-high-dose Methotrexate (HD-MTX) for newly diagnosed, transplant-eligible patients ("Ping-Pong"), followed by Cytarabine (AraC)/Thiotepa (TT), BCNU/TT, and autologous hematologic stem cell transplantation (aHSCT). We retrospectively analyzed a set of 16 patients with high-intermediate or high-risk IPI status. RESULTS: Overall response rate to Ping-Pong was 100% measured by CT/MRI, including 93.75% complete remissions after BCNU/TT followed by PBSCT. One patient failed to qualify for high-dose chemotherapy due to progression when receiving Cytarabine/TT. All patients experienced grade III adverse events, 3 of them a grade IV adverse event. Estimated progression-free survival is 93.75% after a 4.8-year follow-up currently. CONCLUSION: Our study suggests high effectivity of R-CHOP with mid-cycle MTX with aHSCT consolidation towards acceptable OS results in this challenging patient population.

Carfilzomib Based Treatment Strategies in the Management of Relapsed/Refractory Multiple Myeloma with Extramedullary Disease.

Published experience with carfilzomib in patients with relapsed/refractory multiple myeloma (RRMM) and extramedullary disease (EMD) is still limited. The current study aimed to assess the efficacy and safety of carfilzomib containing therapy regimens in EMD. We retrospectively analyzed 45 patients with extramedullary RRMM treated with carfilzomib from June 2013 to September 2019. The median age at the start of carfilzomib was 64 (range 40-80) years. Twenty (44%) and 25 (56%) patients had paraosseous manifestation and EMD without adjacency to bone, respectively. The serological overall response rate (ORR) was 59%. Extramedullary response was evaluable in 33 patients, nine (27%) of them achieved partial remission (PR) (ORR = 27%). In 15 (33%) patients, we observed no extramedullary response despite serological response. The median progression-free survival (PFS) and overall survival (OS) were five (95% CI, 3.5-6.5) and ten (95% CI, 7.5-12.5) months, respectively. EMD without adjacency to bone was associated with a significantly inferior PFS (p = 0.004) and OS (p = 0.04) compared to paraosseous lesions. Carfilzomib based treatment strategies showed some efficacy in heavily pretreated patients with extramedullary RRMM but could not overcome the negative prognostic value of EMD. Due to the discrepancy between serological and extramedullary response, evaluation of extramedullary response using imaging is mandatory in these patients.