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Multiple myeloma (MM) is still extremely difficult to cure, and new therapeutic drugs are needed. We recently found that integrin β7 is constitutively activated in MM cells, and chimeric antigen receptor (CAR) T cells targeting activated integrin β7 have a significant anti-MM effect. In this study, we performed flow cytometry analysis of the expression of activated integrin β7 in bone marrow cells from 137 symptomatic MM patients. In 60/137 (44%) MM patients, activated integrin β7 was detected in most MM cells (> 80% of MM cells were in the positive gate). Activated integrin β7 was highly expressed in MM cells even in heavily treated patients. It also showed high expression in many CD38lo/−CD138−CD19+B cells, which reportedly include clonotypic B cells, in the bone marrow of MM patients. Taken together, these results suggest that CAR T-cell therapy targeting activated integrin β7 has the potential to benefit many patients with relapsed or refractory MM.

A.R.R.O.W. evaluated the superiority of once-weekly carfilzomib plus dexamethasone (Kd) 20/70 mg/m2 vs. twice-weekly Kd 20/27 mg/m2 based on progression-free survival (PFS) in relapsed and/or refractory multiple myeloma patients. Forty Japanese patients (once-weekly arm, n = 26; twice-weekly arm, n = 14) were randomized in A.R.R.O.W. In the Japanese subgroup of A.R.R.O.W., median PFS was 14.8 months (95% confidence interval [CI], 7.5–not evaluable [NE]) and 9.7 months (95% CI, 3.8–NE) in the once- and twice-weekly arms, respectively. The overall response rate (ORR) was 73.1% (19/26; 95% CI, 52.2–88.4) and 57.1% (8/14; 95% CI, 28.9–82.3) in each arm. The adverse events (AEs) incidence was 100% in both arms. Grade ≥ 3 AE incidence was 80.8% (21/26) and 78.6% (11/14) in each arm. Two fatal treatment-related AEs (acute lung injury and acute respiratory distress syndrome) occurred in the once-weekly arm. In exploratory unadjusted analyses of A.R.R.O.W. (once-weekly Kd 20/70 mg/m2) vs. ENDEAVOR (twice-weekly Kd 20/56 mg/m2), median PFS was 14.8 months vs. NE due to not yet being reached, and ORR was 73.1% (19/26) vs. 42.9% (3/7). In the Japanese subgroup, once-weekly Kd tended to improve ORR vs. twice-weekly Kd. Results from A.R.R.O.W. tended to be consistent with results from ENDEAVOR. Electronic supplementary material The online version of this article (10.1007/s12185-020-03013-6) contains supplementary material, which is available to authorized users.

The proband's von Willebrand factor (VWF) antigen and VWF collagen-binding capacity were 14% and 10%, respectively; his sister's were 16% and 9%, respectively; and his nephew's were 30% and 15%, respectively. No apparent loss of high-molecular weight VWF multimers was observed in the plasma of these patients. A single-nucleotide substitution of T to C was found at nucleotide position 113042 in their VWF gene, converting Leu1733 to Pro in the A3 domain. These results suggest that p.Leu1733Pro is responsible for type 2M von Willebrand disease in this family.

This multicenter, open‐label phase 1/2 study evaluated single‐agent carfilzomib in 50 heavily pretreated Japanese patients with relapsed/refractory multiple myeloma (median of five prior treatments). In phase 1, patients were dosed at three levels: 15, 20, or 20/27 mg/m2. Maximum tolerated dosage was not reached at the tolerability evaluation. Patients in phase 2 were treated with 20/27 mg/m2 carfilzomib. Median duration of exposure to carfilzomib in the 20/27 mg/m2 group at this final analysis was 4.7 months (range: 0.3‐39.4). Overall response rate in the 20/27 mg/m2 group, primary endpoint of the study, was 22.5% (n = 9) (95% confidence interval, 12.3‐37.5) with 2.5% (n = 1) stringent complete response. Median progression‐free survival and overall survival in the 20/27 mg/m2 group were 5.1 months (95% CI, 2.8‐13.6) and 22.9 months (95% CI, 14.1‐not estimable), respectively. Frequently occurring grade ≥3 adverse events in the 20/27 mg/m2 group included lymphopenia (72.5%), neutropenia (40.0%), and leukopenia (32.5%). Giving long‐term carfilzomib monotherapy led to long‐term overall survival for heavily pretreated multiple myeloma patients with a favorable safety profile. Carfilzomib monotherapy can be a good option for heavily pretreated multiple myeloma patients.

Differentiation between primary ocular adnexal mucosa-associated lymphoid tissue (POA-MALT) lymphoma and reactive lymphoid hyperplasias sometimes may be difficult. We have examined the treatment-associated mortality of POA-MALT lymphoma after confirmed diagnosis and evaluated their proper treatments. From 1991 through 2016, cases of POA-MALT lymphoma were retrospectively analyzed based on their pathological and molecular/immunological diagnoses. A total of 78 cases with POA-MALT lymphoma with a median age of 66 years were analyzed over median/mean observations of 6.4/7.1 years. Forty-four patients (56%) were diagnosed with IgH gene clonality and 10 patients (13%) were diagnosed with flow cytometric analysis in addition to the pathological decision. The rest (24 patients, 31%) were diagnosed employing pathological decisions of hemato-pathologists and clinical decisions. All patients, except cases of watchful waiting, achieved complete remission. After initial treatment, 68 patients (87%) presented disease-free during the observation period. As treatment, a radiotherapy-based strategy was followed with 15 patients (19%, group A). Immuno-chemotherapy was administered to 24 patients (31%, B). Surgical extraction only was selected for 36 patients (46%, C). Watchful waiting was selected with three patients (4%). Recurrence after the initial treatment was found in one patient (7%) out of A, in three patients (13%) out of B, and in six patients (17%) out of C, respectively. Progression-free survivals at 5 and 10 years were 100 and 100% in A, 95 and 75% in B, and 88 and 81% in C, respectively. The recurrence rates between the patients who were diagnosed with only pathological decision (n = 24) and the patients who were diagnosed with molecular and immunological procedures (n = 54) did not show any statistical differences. Our results indicate that radiotherapy-based treatment strategies for patients with POA-MALT lymphoma show a low rate of recurrence and may improve their prognosis even after the accurate diagnosis. However, contamination of the cases with reactive (polyclonal) lymphoid hyperplasia into those with MALT lymphoma should be carefully removed to avoid unnecessary treatment for malignancies that do not exist.

This nationwide multicentre retrospective study was performed to analyze clinical features that predict the prognosis of central nervous system invasion in multiple myeloma (CNS-MM, approximately 1% of MM). Overall, of the 77 adult patients with CNS-MM identified between 2005 and 2016, those diagnosed at MM diagnosis (n = 3) had longer overall survival (OS) than those diagnosed at relapse (n = 74; median: 48·5 vs 2·7 months). Therefore, we compared the relapsed MM with CNS-MM in patients with any treatment (n = 60). Multivariate analyses revealed that lenalidomide treatment [hazard ratio (HR) 0·27, P = 0·003], intrathecal chemotherapy (IT; HR 0·54, P = 0·05), and radiation therapy (RTx; HR 0·33, P

Maintenance ± consolidation or continuous therapy is considered a standard of care for both transplant–eligible and –ineligible patients with multiple myeloma (MM). However, long-term benefits of such therapy have not yet been clarified in the context of clinical practice. To clarify the efficacy of maintenance/continuous approach, we retrospectively analyzed the cohort data of newly diagnosed MM patients by propensity-score matching based on age, gender, revised International Staging System (R-ISS) stage, and implementation of transplantation to reduce the bias due to confounding variables. Among 720 patients, 161 were identified for each of the maintenance and no maintenance groups. Maintenance/continuous therapy employed immunomodulatory drugs (n = 83), proteasome inhibitors (n = 48), combination of both (n = 29), or dexamethasone alone (n = 1). Progression-free survival (PFS) was significantly prolonged in the maintenance group compared with the no maintenance group (median 37.7 and 21.9 months, p = 0.0002, respectively). Prolongation of PFS was observed in both transplanted and non-transplanted patients (p = 0.017 and p = 0.0008, respectively), with standard risk (p

Background: Novel agents capable of inducing deeper responses dramatically improve the prognosis of patients with multiple myeloma (MM). Innovative technologies such as multiparameter flow cytometry (MFC) and next-generation sequencing (NGS) are utilized to assess minimal residual disease (MRD) for further stratification of patients who achieve a complete response (CR). EuroFlow-next-generation flow (EuroFlow-NGF) is one of the gold standard MFC methods. Recently, both NGF and NGS have been used in many clinical trials to assess MRD levels associated with progression-free survival (PFS) and overall survival (OS). The present study prospectively assessed MRD levels by both NGF and NGS to elucidate the prognostic impact of both methods and clarify their characteristics in MM patients in an autologous stem cell transplantation (ASCT) setting. Methods: We prospectively assessed the response in Japanese patients with newly diagnosed MM who underwent ASCT and lenalidomide-based maintenance therapy at multiple Japanese medical centers between September 2016 and July 2021. The diagnosis of MM and patients' responses to therapy were assessed using the IMWG criteria. Only patients with CR or stringent CR on days 100-365 post-ASCT were included, and bone marrow (BM) samples were obtained to assess MRD. Four milliliters of BM was divided equally. Cells derived from 2 mL BM were analyzed by the NGF method (Flores-Montero et al., Leukemia 2017) at Kanazawa University, and DNA extracted from the remaining 2 mL BM cells was processed by Adaptive Biotechnologies' standardized NGS-MRD assay (Seattle, WA) (Ching et al., BMC Cancer 2020) to assess MRD levels. MRD levels in BM were also monitored at 1-year (± 20 days) and 2-year (± 20 days) post-ASCT. The prognostic value of MRD levels in BM was assessed, and their correlation between NGF and NGS was compared at a cut-off value of 1×10 -5. Sustained MRD negativity was defined as the maintenance of MRD negativity in the BM for more than 6 months. BM cells were analyzed for high-risk cytogenetics (del(17p), t(4;14), and t(14;16)) by FISH. Results: A total of 60 patients (male = 29, female = 31) underwent bortezomib-based induction therapy, ASCT conditioned with high-dose melphalan, and lenalidomide-based maintenance. The median age was 62 years at the ASCT (range 36-71; ISS 1 [n = 13], 2 [n = 24], and 3 [n = 23]). Thirty-three percent of patients showed high-risk chromosomal abnormalities (del17p (n=11), t(4;14) (n=10), t(14;16) (n=2)), 3 patients had double hit diseases, and five patients had extramedullary diseases. With a median follow-up of 3 years, the 3-year progression-free survival (PFS) and 3-year overall survival (OS) rates were 69.2% and 94.2%, respectively. In total, 148 samples were analyzed using NGF and 138 were analyzed using NGS. The rates of MRD negativity at least once using NGF and NGS were 80% and 61%, respectively. The patients who achieved at least one MRD negativity exhibited significantly better 3-year PFS (82.9% by NGF; 84.8% by NGS) than those who did not (P < 0.0001, 0% by NGF; P = 0.005, 49.1% by NGS). Patients who sustained MRD negativity for more than 6 months also showed significantly better 3-year PFS (96.7% by NGF; 92.3% by NGS) compared with those without sustained MRD negativity (Figure; P < 0.0001, 37.1% by NGF; P < 0.01, 50.9% by NGS). The MRD levels between the NGF and NGS methods were significantly correlated with each other (r = 0.9295, P < 0.0001). Among the 17 patients who developed PD after ASCT, seven cases showed discrepancies in the MRD results and two cases in which one case was MRD-positive and the other was MRD-negative by both methods progressed with extramedullary diseases. Five of the seven cases were MRD-positive by NGS and MRD-negative by NGF. Conclusions: In this prospective comparison study of MRD assessment in BM cells using EuroFlow-NGF and NGS approaches, MRD levels highly correlated with each other, and MRD negativity and sustained MRD negativity were significantly associated with prolonged PFS. Multiple MRD assessments by NGF or NGS are essential for predicting durable remission and prolonged clinical outcomes. Figure 1 Figure 1. Disclosures Takamatsu: Bristol-Myers Squibb: Honoraria, Research Funding; Adaptive Biotechnologies, Eisai: Honoraria; SRL: Consultancy; Janssen: Consultancy, Honoraria, Research Funding. Yoshihara: Bristol-Myers Squibb: Honoraria; Janssen: Honoraria; Novartis: Honoraria. Matsumoto: Sanofi: Honoraria; Janssen: Honoraria; Ono: Honoraria; Bristol-Myers Squibb: Honoraria. Yamashita: Janssen: Honoraria; Bristol-Myers Squibb: Honoraria; celgene: Honoraria; Takeda: Honoraria. Fuchida: Takeda Pharmaceutical Co., Ltd.: Honoraria; Ono Pharmaceutical Co., Ltd.: Honoraria; Janssen Pharmaceutical K.K.: Honoraria; Sanofi: Honoraria; Bristol-Myers Squibb Co., Ltd.: Honoraria; Celgene Co., Ltd.: Honoraria. Hiragori: BML: Current Employment. Suzuki: Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria; ONO: Honoraria; Novartis: Honoraria; Sanofi: Honoraria; Abie: Honoraria; Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding. Nakao: Symbio: Consultancy; Kyowa Kirin: Honoraria; Novartis Pharma: Honoraria; Alexion Pharma: Research Funding. Durie: Amgen: Other: fees from non-CME/CE services ; Amgen, Celgene/Bristol-Myers Squibb, Janssen, and Takeda: Consultancy.

This is the first study in which the carfilzomib, lenalidomide and dexamethasone (KRd) regimen was evaluated in heavily pretreated multiple myeloma. This study is a multicenter, open-label phase 1 study of KRd in Japanese patients with relapsed or refractory multiple myeloma (RRMM) patients. The objectives were to evaluate the safety, tolerability, efficacy and pharmacokinetics of the regimen. Carfilzomib was administrated intravenously over 10 min on days 1, 2, 8, 9, 15 and 16 of a 28-day cycle. In cycle 1, the dosage for days 1 and 2 was 20 mg/m2 , followed by 27 mg/m2 . Lenalidomide and dexamethasone were administered at 25 mg (days 1-21) and 40 mg (days 1, 8, 15 and 22), respectively. Twenty-six patients were enrolled. Patients had received a median of four prior regimens and 88.5% and 61.5% received previous bortezomib and lenalidomide, respectively. High-risk cytogenetics were seen in 53.8% of patients. The overall response rate was 88.5%. A higher rate of hyperglycemia was observed than in a previous carfilzomib monotherapy study, but this was attributed to dexamethasone. Carfilzomib pharmacokinetics were not affected by lenalidomide and dexamethasone. The KRd regimen was well tolerated and showed efficacy in Japanese RRMM patients.

We retrospectively analyzed multiple myeloma (MM) patients who underwent autologous stem cell transplantation (ASCT) without maintenance therapy to assess the impact of recovery of normal immunoglobulin (Ig) on clinical outcomes. The recovery of polyclonal Ig was defined as normalization of all values of serum IgG, IgA, and IgM 1 year after ASCT. Among 50 patients, 26 patients showed polyclonal Ig recovery, 14 patients were in &ge, complete response (CR) and 12 remained in non-CR after ASCT. The patients with Ig recovery exhibited a significantly better progression-free survival (PFS, median, 46.8 vs 26.7 months, p = 0.0071) and overall survival (OS, median, not reached vs 65.3 months, p &lt, 0.00001) compared with those without Ig recovery. The survival benefits of Ig recovery were similarly observed in &ge, CR patients (median OS, not reached vs 80.5 months, p = 0.061) and non-CR patients (median OS, not reached vs 53.2 months, p = 0.00016). Multivariate analysis revealed that non-CR and not all Ig recovery were independent prognostic factors for PFS (HR, 4.284, 95%CI (1.868&ndash, 9.826), p = 0.00059, and HR, 2.804, 95%CI (1.334&ndash, 5.896), p = 0.0065, respectively) and also for OS (HR, 8.245, 95%CI (1.528&ndash, 44.47), p = 0.014, and HR, 36.55, 95%CI (3.942&ndash, 338.8), p = 0.0015, respectively). Therefore, in addition to the depth of response, the recovery of polyclonal Ig after ASCT is a useful indicator especially for long-term outcome and might be considered to prevent overtreatment with maintenance therapy in transplanted patients with MM.

These are the results of phase II study of bortezomib-melphalan-prednisolone (VMP) induction therapy followed by lenalidomide-dexamethasone (Rd) consolidation and lenalidomide maintenance in transplant-ineligible patients with newly diagnosed multiple myeloma (NDMM). The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), overall response rates (ORRs), and safety. Eighty-three eligible patients were enrolled between October 2012 and August 2014. The median PFS was 28.0 months (95% CI 19.6–36.7) and the median OS was 55.3 months (95% CI 51.6–NA). Among the patients who received lenalidomide maintenance therapy, median PFS was significantly improved in patients who had achieved a very good partial response (VGPR) or better (41.8 vs 20.7 months, p = 0.0070). As the best response, the rates of partial response or better were 85.5% comprising stringent complete response (sCR, 21.7%), complete response (CR, 10.8%), VGPR (18.1%), and partial response (PR, 34.9%). The most frequently observed grade 3 or higher adverse events during the VMP therapy were anemia (28.9%), neutropenia (15.6%), thrombocytopenia (6.0%), and peripheral neuropathy (2.4%). The most frequently observed grade 3 or higher adverse events during the Rd therapy were anemia (3.5%), neutropenia (1.8%), and skin rush (5.3%). The most frequently observed grade 3 or higher adverse events during lenalidomide maintenance therapy were anemia (7.4%) and neutropenia (24.1%). Thus, VMP induction therapy followed by Rd consolidation and lenalidomide maintenance is considered a well-tolerated and effective regimen in transplant-ineligible NDMM. This trial is registered with UMIN-CTR with the identification number UMIN000009042.

We report the final results from a multicenter, open-label phase I study of carfilzomib plus lenalidomide and dexamethasone in Japanese patients with heavily pretreated relapsed and/or refractory multiple myeloma (RRMM). Twenty-six RRMM patients were enrolled and received a median of 4.0 prior regimens; 12/26 patients (46.2%) completed the planned 18 administration cycles (mean number of cycles: 14.5 ± 4.9). The safety profile was consistent with that of previous carfilzomib studies. All patients experienced adverse events (AEs), but no new safety concerns were observed. The most common grade ≥ 3 AEs (incidence: ≥ 10%) were lymphocyte count decreased (46.2%), platelet count decreased (42.3%), and neutrophil count decreased (34.6%). The overall response rate was 88.5% (23/26; 90% confidence interval: 72.8-96.8). Complete response (CR) or better was achieved by 30.8% of patients compared with 3.8% in the interim analysis. The median time to CR or better response was 9.4 months. Median progression-free survival and duration of response were 19.5 months and 20.3 months, respectively. Median overall survival was not reached. Long-term administration of carfilzomib produced deep response and long-term disease control. The combination of carfilzomib plus lenalidomide and dexamethasone was well tolerated and showed promising clinical efficacy for heavily pretreated RRMM patients. CLINICAL TRIAL REGISTRATION: This clinical trial was registered in the database clinicaltrials.jp (clinical trial registration number: Japic CTI 142677).

We conducted a phase 1/2 study of single-agent carfilzomib in Japanese patients with relapsed/refractory multiple myeloma. Safety, pharmacokinetics and pharmacodynamics of carfilzomib were examined in phase 1. The primary endpoint in phase 2 was the overall response rate (ORR). Carfilzomib was administered in a twice-weekly, consecutive-day dosing schedule. In Phase 1, doses of 15 or 20 mg/m(2) were administered on this schedule or 20 mg/m(2) on Days 1 and 2 of Cycle 1 and then 27 mg/m(2) in the 20/27 mg/m(2) cohort. Patients had a median of five prior therapies, including bortezomib and an immunomodulatory agent. The dose level did not reach the maximum tolerated dose. The most common adverse events were haematological. Notably, carfilzomib either induced new hypertension (n = 4) or aggravated previously existing hypertension (n = 6) in 10 of 50 patients. Four of the eight patients who previously experienced peripheral neuropathy (PN) experienced a recurrence with carfilzomib use, but no new cases of PN occurred. The ORR of the 20/27 mg/m(2) 40 patient cohort was similar to that in the pivotal US study. The dose was efficacious and tolerable in heavily pre-treated Japanese patients; however, meticulous control of hypertension may be necessary for further carfilzomib use.

A prospective, multicenter, phase II study was performed to assess the efficacy and safety of thalidomide maintenance therapy at different doses in Japanese multiple myeloma (MM) patients. This study included 34 patients (median age, 74 years) who were previously treated with not more than three prior therapies and whose response status was evaluated as at least stable disease. They were randomized into Group A (no maintenance; 12 patients), Group B (50 mg thalidomide maintenance; 12 patients), and Group C (100 mg thalidomide maintenance; 10 patients), respectively. Thalidomide maintenance therapy resulted in improved depth of response in three cases (13.6%) and sustained response after induction therapy in eight cases (36.4%). Two-year progression-free survival (PFS) was 25.0%, 33.3%, and 77.8% in Groups A, B, and C, respectively, and was significantly higher in Group C than in Group A (p = 0.005). There was no difference in the incidence of hematological or non-hematological adverse events between Groups B and C. The current study demonstrates that maintenance with daily thalidomide at 100 mg, but not 50 mg, improved depth of response and prolonged PFS, and that this treatment was feasible for use in Japanese MM patients.

In spite of recent development in the treatment armamentarium for multiple myeloma, overall survival (OS) still depends on risk status and sensitivity to treatment of each patient. We have evaluated the clinical relevance of the Revised International Staging System (R-ISS) by comparing it with the original ISS in 718 Japanese patients. The distribution of patients according to response was similar between the ISS and R-ISS stages. Treatment response was greatly influenced by initial treatment modalities and deeper response was observed more frequently in transplanted patients. The R-ISS discriminated the difference in OS between the stages more distinctly than the ISS (p = 9.0 × 10−15 and p = 4.0 × 10−10, respectively). Differences in OS were clarified by both R-ISS and ISS in non-transplanted patients (p = 2.4 × 10−12 and p = 1.4 × 10−8, respectively), but the ISS failed to distinguish the difference between the stages in transplanted patients (p = 0.13). In contrast, the R-ISS could at least discriminate the excellent prognosis of stage I patients whereas the distinction between stage II and III was not that clear (p = 0.033). The R-ISS stage II encompassed a large number of patients, and the prognosis was heterogeneous depending on the fulfillment of prognostic factors such as LDH and adverse cytogenetics. These results suggest that treatment factors and prognostic factors greatly affect the therapeutic response and outcome, and the R-ISS is superior to ISS in prognostication of both transplant-eligible and -ineligible patients in our current clinical practice.

The international staging system (ISS) is the most commonly used risk-stratification system for patients with multiple myeloma (MM) and is determined by serum albumin and β2-microglobulin levels. In the two determinants, β2-microglobulin levels are frequently observed to be elevated in patients with myeloma, particularly in those with renal impairment. In comparison with patients with intact immunoglobulin myeloma, patients with LC myeloma do not necessarily show decreased levels of serum albumin. The clinical impact of ISS in patients with LCMM, in particular the distinction between ISS I and II, may be complicated due to non-decreased levels of serum albumin in both stages. Accordingly, we have attempted to assess clinical relevance of the ISS in patients with LC myeloma. The clinical data of 1899 patients with MM diagnosed between January 2001 and December 2012 were collected from 38 affiliated hospitals of the Japanese Society of Myeloma. Significant difference was not found between stage I (n = 72) and stage II (n = 92) in LC myeloma patients (n = 307). The mean serum albumin concentration of patients with LC myeloma was within the reference range but higher than that of patients with IgG + IgA myeloma (n = 1501), which complicates the distinction between ISS stage I and II myeloma. Patients with LC myeloma had low frequencies of t(4; 14) and high frequency of elevated lactate dehydrogenase, and despite a relevant amount of missing data in our registry (R-ISS stage I; n = 11, stage II; n = 32, and stage III: n = 18), the information included in the R-ISS scoring system seems to be more accurate than ISS to obtain a reliable risk stratification approach in non-ISS stage III LC myeloma patients.

The authors would like to correct the errors in the publication of the original article. The correction details are given below.

We investigated the treatment and outcome of Japanese patients with primary plasma cell leukemia (pPCL) in the era of novel agents and analyzed the risk factors affecting survival. Among 3,318 patients with symptomatic multiple myeloma (MM), 38 patients were diagnosed with pPCL. The median overall survival (OS) of the pPCL patients was 2.85 years, which was significantly extended compared with that in previous reports. The proportion of patients treated with novel agents was 61%. The OS of the patients treated with novel agents was significantly extended compared with that of patients treated without novel agents according to the generalized Wilcoxon test (2.85 vs. 1.16 years, p = 0.049). This statistical finding suggests that treatment with novel agents could have prevented early death in the patients with pPCL. Age was the only statistically significant prognostic factor associated with an inferior OS (hazard ratio 4.57). Five patients received maintenance therapy with novel agents, and their OS tended to be longer than that of the other patients without maintenance (4.45 vs. 2.85 years). Unlike MM, OS for pPCL has not been improved significantly over the last decade, especially in elderly patients. Therefore, it is important to establish the treatment strategy, particularly after induction treatment.

An 81-year-old man was referred to our department because of suspected factor VII (FVII) deficiency. His FVII activity was under 1%, whereas the FVII activity levels of his son and granddaughter were 65 and 109%, respectively. The nucleotide at position 3886 of his FVII gene was homozygous for G. A single T to G substitution results in the replacement of wild-type Cys at residue 22 by Gly. His son was heterozygous for G and T at position 3886, whereas his granddaughter was homozygous for wild-type T. These results suggest that he was homozygous for FVII Cys22Gly. He underwent radiofrequency ablation (RFA) for hepatocellular carcinoma, receiving 20 μg/kg of recombinant FVIIa prior to RFA and 10 μg/kg of recombinant FVIIa twice after RFA. He showed no bleeding tendency; however, a myocardial infarction was diagnosed and percutaneous coronary intervention was performed.

Background: Treatment of multiple myeloma has evolved considerably in the past few years with availability of several news drugs as well as increasing use of multidrug combinations. These changes have no doubt led to the improved survival seen among patients with MM. We have previously shown that outcomes of patients intolerant or refractory to one of the IMiDs and bortezomib had a poor outcome. Since that time, other drugs of the same class as well as new classes of drugs have been introduced for the treatment of MM. We designed this retrospective study to estimate the outcomes in patients with relapsed myeloma, who have become refractory to the current generation IMiDs and proteasome inhibitors. Patients and Methods: Patients with relapsed multiple myeloma who have received at least 3 prior lines of therapy, is refractory to both an IMiD (lenalidomide or pomalidomide) AND a proteasome inhibitor (bortezomib or carfilzomib), and has been exposed to an alkylating agent were identified from multiple centers. The time patients met the above criteria was defined as T0, and details of all treatment regimens before and after T0 were collected using electronic CRFs. The study was approved by the IRB at the respective centers. Results: 543 patients were enrolled in this study; median age was 62 years (31-87) and 61% were males. Patients were enrolled from centers in North America (n=181), Europe (n=318), and Asia Pacific (n=44). Patients were diagnosed between 2006 and 2014, the median duration between diagnosis of myeloma and study entry (T0) was 3.1 years (0.3 to 9). The median (95% CI) estimated follow up from diagnosis and from T0 were 61 (57, 66) months and 13 (11, 15) months respectively. The median number of lines of therapy prior to T0 was 4 (3-13), 48% had a prior transplant. The median OS from T0 for the entire cohort was 13 (11, 15) months. For these 462 patients, the median number of recorded regimens was 2 (1-9). The overall response and the depth of response to each line of treatment following T0 are as shown in the table. The median (95% CI) PFS and OS from T0 was 5 (4, 6), and 15.2 (13, 17), respectively. The overall survival for the 81 patients with no treatment post T0 was only 2.1 months. In a multivariate analysis, duration from diagnosis to T0, ISS stage III and number of lines of therapy were all associated with inferior PFS, as well as OS, and in addition, serum creatinine>2 mg/dL at T0 also predicted inferior OS. Conclusions: The study provides the expected outcome following development of myeloma that is refractory to a PI and an IMiD. The outcomes of these patients appear to be better than we had seen historically in patients refractory/ intolerant to bortezomib and IMiDs, highlighting the increased treatment options available for these patients. However, there is decreasing response rate to sequential regimens highlighting the development of drug resistance. The data provides a bench mark for comparison of new therapies that are being evaluated in this disease. Table Table. Disclosures Dimopoulos: Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genesis: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Kastritis:Takeda: Consultancy, Honoraria; Genesis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Terpos:BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Celgene: Honoraria; Takeda: Consultancy, Honoraria; Genesis: Consultancy, Honoraria, Other: Travel expenses; Amgen: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Novartis: Honoraria. Hillengass:Sanofi: Research Funding; Novartis: Research Funding; Amgen: Consultancy, Honoraria; BMS: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria. Leleu:TEVA: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; LeoPharma: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria; Pierre Fabre: Honoraria; Celgene: Honoraria; Novartis: Honoraria; Takeda: Honoraria. Oriol:Janssen: Honoraria, Other: Expert board committee; Amgen: Honoraria, Other: Expert board committee. Cavo:Celgene: Consultancy, Honoraria; Millennium: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Janssen-Cilag: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Mateos:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees. Vij:Shire: Consultancy; Takeda: Consultancy, Research Funding; Jazz: Consultancy; Karyopharma: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Celgene: Consultancy; Bristol-Myers Squibb: Consultancy; Amgen: Consultancy, Research Funding. Lokhorst:Genmab: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. van de Donk:Amgen: Research Funding; Janssen: Research Funding; BMS: Research Funding; Celgene: Research Funding. Mark:Onyx: Research Funding, Speakers Bureau; Millenium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Ludwig:Amgen: Research Funding, Speakers Bureau; Takeda: Research Funding, Speakers Bureau; BMS: Speakers Bureau; Janssen: Speakers Bureau. Jagannath:Novartis: Consultancy; Janssen: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy; Merck: Consultancy. Usmani:Array: Research Funding; Britsol-Myers Squibb: Consultancy, Research Funding; Skyline: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BioPharma: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Consultancy, Research Funding, Speakers Bureau; Millenium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Speakers Bureau. Dytfeld:Janssen Poland: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees. Moreau:Novartis: Honoraria; Amgen: Honoraria; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria; Janssen: Honoraria, Speakers Bureau. Lee:Amgen: Membership on an entity's Board of Directors or advisory committees. Shustik:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. de la Rubia:Celgene: Consultancy; Bristol Myers: Consultancy; Amgen,: Consultancy; Janssen: Consultancy. Durie:Takeda: Consultancy; Amgen: Consultancy; Janssen: Consultancy.

Novel agents such as thalidomide, lenalidomide and bortezomib have dramatically changed the treatment paradigm of multiple myeloma (MM). However, it is not clear whether these agents improve the prognosis of elderly patients who have undergone autologous stem cell transplantation (auto-SCT). We retrospectively analyzed the outcome of 318 newly diagnosed patients aged 65-70 years who were treated between January 1, 2004, and December 31, 2009. As initial therapy, 192 patients were treated with conventional chemotherapy, 88 with novel agent-containing regimens, 21 with conventional chemotherapy plus auto-SCT and the remaining 17 with novel agents plus auto-SCT. The median progression-free survival was 19.1, 24.5, 26.8 and 35.2 months, respectively, and the 5-year overall survival (OS) was 40, 62, 63 and 87%, respectively. Initial therapy with novel agents (p < 0.001) or auto-SCT (p < 0.02) significantly improved OS compared with the group without these treatment modalities. Salvage therapy with novel agents also significantly improved survival after relapse compared with conventional chemotherapy alone (p < 0.04). In a multivariate analysis, the use of novel agents was an independent prognostic factor significantly associated with extended OS (p < 0.003). These results indicate that novel agents and auto-SCT had a major impact on OS in eligible patients in this subgroup of MM.

Introduction: Survival outcome of patients with multiple myeloma (MM) is heterogeneous because of different disease- and patient-related prognostic factors as well as in treatment-related factors. A survival benefit of continuous and maintenance (C/M) therapies after induction therapy in both transplant-eligible and -ineligible patients has been demonstrated in clinical trials. However, its usefulness is still to be clarified in the patients treated in routine clinical practice. Here, we report survival outcome of patients who received C/M therapy after induction therapy by analyzing the data of a multicenter retrospective study of the Japanese Society of Myeloma. Methods: Compiled clinical data of the patients diagnosed with MM and treated between 2013 and 2016 were analyzed retrospectively. Treatment decision whether or not to implement autologous stem cell transplantation (ASCT) was made at the discretion of a physician-in-charge. Treatment response was assessed by the investigators according to the International Myeloma Working Group uniform response criteria. Treatment decision to implement maintenance therapy after ASCT or to continue frontline treatment in non-transplanted patients was made based on the response to frontline treatment by the physician-in-charge. Patients were bifurcated using the propensity score methods in terms of age, gender, R-ISS stage, and commencement of ASCT to those who received C/M therapy and others without. Results: A total of 771 patients were enrolled. Among them, 216 patients received frontline C/M therapy, while the remaining 555 patients did not. In 720 patients who have achieved at least stable disease after induction therapy with or without ASCT, 161 patients of C/M group and another 161 patients of non-C/M group were matched according to the baseline covariates. Patient demographics and disease characteristics were well balanced between the matched set of patients (C/M vs non-C/M) in terms of median age (years, 65 vs 65), gender (male, 52% vs 53%), and R-ISS (stage I, 19% vs 20%; stage II, 70% vs 69%; and stage III, 11% vs 11%), respectively. ASCT were performed in 54% vs 54% in either group. C/M regimens included lenalidomide (n=73), bortezomib (n=35), ixazomib (n=9), elotuzumab (n=6), thalidomide (n=5), carfilzomib (n=2), combination of proteasome inhibitors and IMiDs (n=28), and others (n=3). Median PFS was significantly prolonged in the C/M group compared with the non-C/M group (37.7 vs 21.6 months, p=0.00017, Figure A). Median PFS in each of the two groups of the transplanted and non-transplanted patients were 40.5 vs 29.5 months (p=0.0063) and 24.6 vs 11.2 months (p=0.0013), respectively. For patients who have attained a CR after the frontline therapy, there was no significant difference in median PFS between the C/M and non-C/M groups (not reached vs 37.5 months, p=0.39). However, there was a significant prolongation of median PFS in the C/M group among those who did not achieve a CR (33.0 vs 19.2 months, p=0.006). Median OS was not reached in either groups, but it appeared to be longer in the C/M group than in the non-C/M group (p=0.061, Figure B). Although median OS of both groups were similar in the transplanted patients (p=0.56), there was a significant prolongation in the non-transplanted patients (58.1 months vs not reached, p=0.024). For those who have attained a CR, there was no significant difference in median OS between the C/M and non-C/M groups (p=0.29), but for those who did not achieve a CR, there was a significant prolongation of median OS in the C/M group (58.1 months vs not reached, p=0.048). A significant beneficial impact of C/M therapy on PFS and OS was observed in the R-ISS stage II and III patients but not in the stage I patients. In multivariate analysis, R-ISS stage, CR response after frontline therapy, ASCT, and C/M therapy were significant prognostic factors for PFS, whereas R-ISS and C/M therapy were associated with prolonged OS. Conclusions: C/M therapy had a beneficial impact on PFS and OS especially in patients with non-transplanted, non-CR response, and R-ISS stage II and III cohorts, but exerted less impact on standard-risk patients in our current clinical practice. Thus, C/M therapy is a key strategy for high-risk patients, but clarification of patients other than risk status who benefit from C/M therapy might be needed to further improve the prognosis of high-risk patients with MM. Disclosures Handa: Ono: Research Funding. Sunami:MSD: Research Funding; GSK: Research Funding; Abbvie: Research Funding; Novartis: Research Funding; Alexion-pharma: Research Funding; Janssen: Research Funding; Takeda: Honoraria, Research Funding; Sanofi: Research Funding; Daiichi Sankyo: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Suzuki:Ono: Research Funding; BMS: Honoraria, Research Funding; Takeda: Honoraria; Janssen: Honoraria; Celgene: Honoraria. Iida:Takeda: Honoraria, Research Funding; Sanofi: Research Funding; Gilead: Research Funding; Celgene: Honoraria, Research Funding; Daichi Sankyo: Honoraria, Research Funding; Kyowa Kirin: Research Funding; Abbvie: Research Funding; Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; MSD: Research Funding; Chugai: Research Funding; Janssen: Honoraria, Research Funding; Astellas: Research Funding; Teijin Pharma: Research Funding. Nishimura:Chugai-Roche Pharmaceuticals Co.,Ltd.: Consultancy; Celgene K.K.: Honoraria. Shimizu:Amgen: Consultancy; Fujimoto: Consultancy; Daiichi: Consultancy; Medical Biological Laboratory: Consultancy; Takeda: Speakers Bureau.

Endoplasmic reticulum (ER) stress is induced in matrix-producing osteoblasts and plays an essential role in osteoblastogenesis. Although the bone anabolic activity of proteasome inhibitors has been demonstrated, the roles of ER stress induced by proteasome inhibition in osteoblastogenesis remain largely unknown. Here we show that bortezomib translationally increases protein levels of activating transcription factor 4 (ATF4), a downstream mediator of ER stress, in bone marrow stromal cells and MC3T3-E1 preosteoblastic cells. The suppression of ATF4 expression by siRNA abrogated osteocalcin expression and mineralized nodule formation by MC3T3-E1 cells induced by bortezomib, indicating a critical role for ATF4 in bortezomib-mediated osteoblastogenesis. However, bortezomib at 20 nM or higher abolished the mineralized nodule formation along with reductions in the expression of osteoblastogenesis mediators β-catenin and Osterix. Furthermore, at 50 nM, bortezomib induced the expression of C/EBP homologous protein (CHOP), suggesting activation of the ATF4-CHOP pro-apoptotic pathway. These results suggest that a low dose of bortezomib induces osteogenic activity, but that, in contrast, excessive ER stress caused by bortezomib at higher doses hampers osteoblastogenesis. Therefore, dosing schedules for proteasome inhibitors warrant further study to maximize anabolic actions without compromising anti-MM activity in patients with multiple myeloma (MM).

We herein report the case of a 77-year-old man admitted for an acute cutaneous infection and persistent fever. A physical examination revealed systemic small blisters and scrotal swelling. He was suspected of having complications from chickenpox or bullous impetigo as the initial diagnosis. Nocardia was detected on an aspiration biopsy of the small blisters and the surgically removed testis at a later date. Testicular nocardiosis is a rare condition; however, we should consider nocardiosis in the differential diagnosis because delay in providing treatment may worsen a patient's general condition.

Hexokinase II (HKII), a key enzyme of glycolysis, is widely over-expressed in cancer cells. However, HKII levels and its roles in ATP production and ATP-dependent cellular process have not been well studied in hematopoietic malignant cells including multiple myeloma (MM) cells.We demonstrate herein that HKII is constitutively over-expressed in MM cells. 3-bromopyruvate (3BrPA), an inhibitor of HKII, promptly and substantially suppresses ATP production and induces cell death in MM cells. Interestingly, cocultures with osteoclasts (OCs) but not bone marrow stromal cells (BMSCs) enhanced the phosphorylation of Akt along with an increase in HKII levels and lactate production in MM cells. The enhancement of HKII levels and lactate production in MM cells by OCs were mostly abrogated by the PI3K inhibitor LY294002, suggesting activation of glycolysis in MM cells by OCs via the PI3K-Akt-HKII pathway. Although BMSCs and OCs stimulate MM cell growth and survival, 3BrPA induces cell death in MM cells even in cocultures with OCs as well as BMSCs. Furthermore, 3BrPA was able to diminish ATP-dependent ABC transporter activity to restore drug retention in MM cells in the presence of OCs. These results may underpin possible clinical application of 3BrPA in patients with MM.

A standard treatment for acquired amegakaryocytic thrombocytopenic purpura (AATP) has not yet been established. Once AATP is diagnosed, a therapeutic trial of cyclosporine, with or without antithym...

Background: We recently reported that the International Prognostic Scoring System for Waldenström macroglobulinemia (ISSWM), which is widely used to predict the prognosis of WM patients, might not be applicable to Japanese patients, and evidence of pleural effusion might be a novel adverse prognostic factor for symptomatic WM in the rituximab era. Further studies with a large number of patients are deemed to be conducted. Methods: We retrospectively analyzed the clinical data of 498 patients with WM diagnosed between January 2001 and December 2015 from 44 institutes involved with the Japanese Society of Myeloma. The overall survival (OS) was analyzed using Kaplan-Meier methods and compared using log-rank test. Several clinical characteristics at the diagnosis were assessed by Cox regression for univariate and multivariate analyses of the OS. Results: We included 420 cases diagnosed with symptomatic (n=314) and asymptomatic WM (n=106) in accordance with the classification of the Second International Workshop on WM. The median age at the diagnosis was 69 (range, 32-91) years, with 75.5% male, and 16.0% had an Eastern Cooperative Oncology Group performance status (ECOG PS) of 2-4. Oral alkylating agents, purine analogs, cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP) or CHOP-like regimens ± rituximab, rituximab monotherapy, or dexamethasone, rituximab and cyclophosphamide (DRC) were mainly administered as initial treatment. Rituximab-containing therapy was administered in 76.8% of all patients. The median follow-up was 45 months. The 5-year OS rate for all patients was 77.9%, while the rates for those with symptomatic and asymptomatic WM were 72.9% and 92.2%, respectively. Significant differences in the survival were seen between risk groups of ISSWM in symptomatic WM patients (5-year OS: high, 55.4%; intermediate, 81.2%; low, 90.2%; p65 years, platelet count ≤10×104/µL, serum β2-microglobulin (β2-MG) >3 mg/L, ECOG PS 2-4, abnormal karyotype, pleural involvement, WBC 1.5 mg/dL, CRP >2.0 mg/dL and sIL-2R >4000 U/mL were significant adverse prognostic factors for the OS. A multivariate analysis revealed that a platelet count ≤10×104/µL (hazard ratio [HR] 5.942; 95% confidence interval [CI] 2.265-14.761), serum β2-MG >3 mg/L (HR 2.748; 95% CI 1.091-7.655), ECOG PS 2-4 (HR 2.899; 95% CI 1.219-6.290), and pleural involvement (HR 11.066; 95% CI 3.672-29.829) were adverse independent risk factors for symptomatic WM. We constructed a prognostic model by combining these prognostic variables as follows: patients with good risk (n=219), no adverse factors or only serum β2-MG >3 mg/L or ECOG PS 2-4; patients with poor risk (n=81), ≥1 adverse factors with a platelet count ≤10×104/µL, pleural involvement, or both serum β2-MG >3 mg/L and ECOG PS 2-4. The 5-year OS rates were 82.3% for good risk and 44.4% for poor risk, and this prognostic model significantly stratified symptomatic WM patients separately by the survival (p Conclusion: Although ISSWM may be useful for survival risk stratification in Japanese patients, we found that intermediate- and high-risk patients seemed to have a better prognosis than those in Western studies in the rituximab era (Dimopoulos MA, et al. Haematologica. 2008; 93: 1420-22). Thrombocytopenia and pleural involvement were found to be strong adverse prognostic factors in symptomatic WM, and our new prognostic index including them was easy to use in daily clinical practice and superior to ISSWM for detecting high-risk patients. Further studies are warranted to validate our prognostic index, especially in the era of novel agents. Disclosures Yamamoto: Bristol-Myers Squibb: Honoraria. Hagiwara:Celgene: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Sunami:Celgene: Honoraria, Research Funding; Sanofi: Research Funding; Janssen: Research Funding; Daiichi-Sankyo: Research Funding; Ono: Honoraria, Research Funding; Bristol-Myers Squibb K.K.: Honoraria, Research Funding; AbbVie: Research Funding; Takeda: Research Funding; MSD: Research Funding; GlaxoSmithKline: Research Funding; Novartis: Research Funding. Kurokawa:Teijin Pharma: Research Funding; Eizai: Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Chugai Pharmaceutical: Research Funding; Sumitomo Dainippon Pharma: Research Funding; Pfizer: Research Funding; Takeda Pharmaceutical: Research Funding; MSD: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Nippon Sinyaku: Honoraria, Research Funding; Astellas Pharma: Research Funding; Otsuka Pharmaceutical: Research Funding. Takamatsu:Janssen: Honoraria; Celgene: Honoraria, Research Funding; Bristol-Myers Squibb: Research Funding; Ono: Research Funding. Ito:Bristol-Myers Squibb, Celgene: Honoraria. Tamura:Bristol-Myers Squibb: Honoraria; Celgene: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria; Takeda Pharmaceutical: Honoraria.

Survival outcome of patients with multiple myeloma (MM) has been markedly improved by the introduction of novel agents such as bortezomib, thalidomide, and lenalidomide over the past decade. Recent clinical studies have shown further improvement by second-generation agents, namely carfilzomib, ixazomib, pomalidomide, elotuzumab, and daratumumab. However, the prognosis of patients who became refractory to both bortezomib and lenalidomide was extremely poor, and the efficacy of the second-generation agents in such patient remains unclear in routine clinical practice. In this study, we analyzed the outcome of MM patients in terms of overall survival (OS) and survival time after salvage therapy. A total of 174 patients (89 male and 85 female) treated between 2003 and 2017 were enrolled. The median age was 69 years old (range 35-89). The type of M protein was IgG in 93, IgA in 35, IgD in 10, Bence Jones type in 30, and non-secretory type in 5 patients, respectively. The international staging system (ISS) stages I, II, and III were 32, 66, and 63 patients, respectively. There were 100 patients with normal serum LDH and 39 with high LDH. As for initial therapy, 62 patients were treated with conventional chemotherapy, 83 with bortezomib-based regimens, 7 with lenalidomide-based regimens, and 22 with bortezomib + lenalidomide + dexamethasone. Forty-seven patients received autologous stem cell transplantation in the upfront setting. During the observation period 120 patients relapsed and 6 were refractory to initial therapy, and 38 patients were treated with conventional chemotherapy and 58 with the first-generation novel agents such as bortezomib, lenalidomide, or thalidomide as salvage therapy. The remaining 30 patients were further treated with the second-generation novel agents such as carfilzomib in 21, ixazomib in 5, pomalidomide in 6, elotuzumab in 4, or daratumumab in 8 patients after refractory to bortezomib and lenalidomide. The median progression-free survival was 17.7 months and the median OS was 51.0 months from initial therapy. Regarding the outcome according to salvage therapy, the median OS was 22.0 months for conventional chemotherapy group, 46.4 months for first-generation agent group, and 98.7 months for second-generation agent group (p Figure. Figure. Disclosures No relevant conflicts of interest to declare.

e19534Background: Differentiation between primary ocular adnexal mucosa-associated lymphoid tissue (POA-MALT) lymphoma and reactive lymphoid hyperplasias sometimes may be difficult. We have examine...

We report a patient with refractory multiple myeloma (MM) who developed platelet transfusion refractoriness (PTR). A 61-year-old woman was diagnosed with MM in July 2003. She underwent high-dose chemotherapy followed by autologous stem cell transplantation, and achieved a very good partial response. However, she relapsed in June 2006, and was referred to our hospital in October of the same year. Laboratory examinations showed pancytopenia and increased plasma cells in the peripheral blood. Platelet transfusions from random donors became ineffective, and anti-HLA class I antibody (83.8% positive) was detected in the serum by flow cytometry assay (Flow PRA). Therefore, she was considered to have developed PTR due to anti-HLA class I antibody caused by the previous blood transfusions. She was transfused with HLA-matched platelets, and then treated with bortezomib plus dexamethasone (BD) for refractory MM. The serum IgG level decreased from 7,451 to 1,735 mg/dL, and HLA class I antibody was markedly decreased to 1.9%. In addition, platelet transfusion from random donors showed clinical effects after BD therapy. This case suggests that bortezomib might be effective in different types of immune disease by inhibiting allo-reactive antibody.

Multiple myeloma is still an incurable disease, most commonly occurring in the elderly. The myeloma-induced bone marrow microenvironment protects myeloma cells from drug-induced apoptosis. Therefore, the development of novel and tolerable therapeutic alternatives to overcome the drug resistance is an important clinical issue. Valproic acid (VPA), a safe and widely used anti-epileptic agent, is revisited as a class I- and IIa-specific histone deacetylase inhibitor. In the present study, we evaluated the effect as well as a mechanism of actions of VPA on myeloma cell growth and survival, with special reference to the myeloma-induced bone marrow microenvironment. VPA at therapeutic concentrations for epilepsy induced cell death in primary CD138-positive myeloma cells as well as myeloma cell lines, but not in CD138-negative bone marrow cells. VPA suppressed osteoclastogenesis as well as osteoclast-mediated myeloma cell growth. VPA also inhibited vascular tubule formation enhanced by co-cultures of myeloma cells and osteoclasts in concert with thalidomide. In addition, VPA induced both caspase-dependent and -independent cell death in myeloma cells, and potentiated the anti-myeloma effects of melphalan and dexamethasone. Collectively, VPA is suggested to exert multi-factorial anti-myeloma actions, and may serve as a safe adjuvant to be included in conventional chemotherapies against myeloma.

Purpose: Similar to osteoclastogenesis, angiogenesis is enhanced in the bone marrow in myeloma in parallel with tumor progression. We showed previously that myeloma cells and osteoclasts are mutually stimulated to form a vicious cycle to lead to enhance both osteoclastogenesis and tumor growth. The present study was undertaken to clarify whether myeloma cell-osteoclast interaction enhances angiogenesis and whether there is any mutual stimulation between osteoclastogenesis and angiogenesis. Experimental Design: Myeloma cells and monocyte-derived osteoclasts were cocultured, and angiogenic activity produced by the cocultures was assessed with in vitro vascular tubule formation assays and human umbilical vascular endothelial cell (HUVEC) migration and survival. Osteoclastogenic activity was determined with rabbit bone cell cultures on dentine slices. Results: Myeloma cells and osteoclasts constitutively secrete proangiogenic factors, vascular endothelial growth factor (VEGF) and osteopontin, respectively. A cell-to-cell interaction between myeloma cells and osteoclasts potently enhanced vascular tubule formation. Blockade of both VEGF and osteopontin actions almost completely abrogated such vascular tubule formation as well as migration and survival of HUVECs enhanced by conditioned medium from cocultures of myeloma cells and osteoclasts. Furthermore, these factors in combination triggered the production of osteoclastogenic activity by HUVEC. Conclusions: Osteoclast-derived osteopontin and VEGF from myeloma cells cooperatively enhance angiogenesis and also induce osteoclastogenic activity by vascular endothelial cells. These observations suggest the presence of a close link between myeloma cells, osteoclasts, and vascular endothelial cells to form a vicious cycle between bone destruction, angiogenesis, and myeloma expansion.

AL amyloidosis is a disease in which immunoglobulin L chain is deposited in multiple organs, and the prognosis of cardiac amyloidosis is extremely poor. Although several treatments based on that for multiple myeloma, have been performed, there is no clear evidence that cardiac function is improved. We report a case of AL cardiac amyloidosis with moderate cardiac dysfunction for which we performed autologous peripheral blood stem cell transplantation (auto-PBSCT) in combination with high-dose melphalan therapy. This treatment resulted in significant improvement in cardiac function and good prognosis for about 3.5 years after the diagnosis. Therefore, auto-PBSCT is a possible option as up-front therapy for AL cardiac amyloidosis.

Bortezomib is one of the most widely used novel drugs for the treatment of multiple myeloma (MM). However, twice-weekly intravenous administration is associated with innegligible adverse events and treatment discontinuation. We therefore evaluated the long-term efficacy and feasibility of reduced frequency treatment with intravenous bortezomib in elderly patients with relapsed and/or refractory MM. A total of 47 bortezomib-naive patients (median age 75 years) received bortezomib (1.3 mg/m2, intravenously) and dexamethasone (20 mg) on days 1, 8, and 15 of every 4-week cycle. Twenty-six patients completed the planned 8 cycles. Best responses were stringent complete response (sCR) in 5 patients, very good partial response (VGPR) in 3, PR in 15, stable disease (SD) in 18, and disease progression (PD) in 6, respectively. Median progression-free and overall survivals were 9.6 and 35.1 months, respectively. After progression, 11 patients were retreated with bortezomib-based regimens and another 24 patients with immunomodulatory drugs. Multivariate analysis revealed that ISS 3, t(4;14), and

Macrophage inflammatory protein (MIP)-1alpha and MIP-1beta have been identified as candidates for multiple myeloma (MM)-derived bone-resorbing factors. To validate the clinical relevance of these observations, we investigated correlations between the ability of MM cells to secrete these chemokines and the extent of MM bone lesions as well as levels of biochemical bone markers in patients with MM. Patients with multiple bone lesions exhibited higher MIP-1alpha and MIP-1beta secretion from MM cells along with elevated urinary deoxypyridinoline (Dpd), without significant elevation of serum bone-specific alkaline phosphatase (BALP) or osteocalcin compared with those with minimal bone lesions. MIP-1alpha and MIP-1beta levels correlated positively with urinary Dpd and serum BALP but not with serum osteocalcin. These results provide further evidence for a causal role of MIP-1alpha and MIP-1beta in the development of lytic bone lesions, and suggest that MM cells suppress osteoblastic bone formation to cause an imbalance of bone turnover and development of destructive bone lesions.

More than 300 cases of acquired von Willebrand syndrome (AVWS) have been reported, but it is thought that this number reflects only the tip of the iceberg [1]. Data from an international registry has shown that AVWS may be associated with lymphoproliferative (48%) or myeloproliferative (15%) disorders, neoplasia (5%), immunological (2%), cardiovascular (21%) and miscellaneous conditions (9%) [2]. AVWS usually mimics von Willebrand disease (VWD) type 1 or 2A [3, 4]. To our knowledge, only two cases of type 2B-like AVWS have been reported previously [4, 5]. They were both associated with plasma cell dyscrasia. Here we show a new case of type 2B-like AVWS. On 2 November 2000, a 74-year-old man was referred to our hospital for the follow-up of monoclonal gammopathy of undetermined significance (MGUS). Serum immunoelectrophoresis showed two kinds of M protein, IgG (j) and IgG (k). The serum immunoglobulin levels were IgG 2289 mg/dl, IgA 175 mg/dl, and IgM 63 mg/dl. He remained relatively well until 24 July 2008, when he developed a high fever. A diagnosis of hydronephrosis and urinary tract infection due to prostatic hypertrophy was made and after transurethral resection of the prostate, which was performed on 22 August 2008, macrohematuria persisted for 4 weeks despite administration of tranexamic acid. There was no other mucocutaneous bleeding. His serum IgG level had hardly changed up to that point. Routine coagulation tests demonstrated: prothrombin time, 11.4 s (normal 10.0–13.5 s); activated partial thromboplastin time, 48.5 s (normal 25.0–40.0 s); plasma fibrinogen level, 298 mg/dl. Factor VIII activity (FVIII:C) was 17% (normal 50–150%), von Willebrand factor antigen (VWF:Ag) was 11% (normal 50–150%) and von Willebrand factor ristocetin cofactor activity (VWF:RCo) was below 10% (normal 50–150%). Activities of factor IX, factor XI and factor XII were all normal. Bleeding time was 2.0 min (normal 1.0–5.0 min). The platelet count was consistently normal. Platelet aggregation induced by ADP, collagen or epinephrine was increased when compared to that in the control. Ristocetin-induced platelet aggregation (RIPA) was also enhanced, showing 70% aggregation with 0.3 mg/ml ristocetin compared with absent aggregation in a normal control (Fig. 1). His platelet-rich plasma (PRP) aggregated spontaneously without the addition of any agonists. All aggregation studies were performed with an aggregometer (MC Medical, Tokyo, Japan) in siliconized glass cuvettes at 37.0 ± 0.5 C with constant stirring at 1000 ± 100 rpm. Plasma VWF multimeric analysis showed that large multimers were absent and medium multimers were markedly decreased. Since these results T. Shigekiyo (&) E. Sekimoto A. Shirakami H. Yamaguchi H. Shibata S. Ozaki Department of Internal Medicine, Tokushima Prefectural Central Hospital, 1-10-3 Kuramoto-cho, Tokushima 770-0042, Japan e-mail: shigekiyo@tph.gr.jp

Multiple myeloma (MM) is a plasma cell malignancy characterized by the presence of monoclonal immunoglobulin and related end-organ damages [1]. Lenalidomide is one of the most potent immunomodulatory drugs (IMiDs) that induce significant anti-tumor effects in patients with newly diagnosed and refractory MM [2–5]. This agent also has pleiotropic properties including immunomodulatory and anti-inflammatory effects, and has been shown to stimulate T cells and NK cells to produce Th1 type cytokines such as interleukin (IL)-2 and interferon-c, while displaying inhibitory effects on the production of Th2 type cytokines and pro-inflammatory cytokines such as IL-4, IL-6, and tumor necrosis factor a (TNF-a) in vitro [6]. The clinical relevance of such immunomodulatory effects is yet to be elucidated in patients with MM. Here, we report two patients with relapsed MM who showed transient inflammatory reaction during lenalidomide plus reduced-dose dexamethasone therapy. Case 1 A 49-year-old male was suffering from MM (IgGj type) in stage IIA and international staging system (ISS) 2. He was treated with three courses of vincristine, adriamycin, and dexamethasone (VAD); however, his disease activity was not improved. He received two courses of BD therapy (bortezomib 1.3 mg/m on days 1, 4, 8, and 11, and dexamethasone 20 mg on days 1, 2, 4, 5, 8, 9, 11, and 12), and achieved very good partial response (VGPR). One month later, he experienced grade 3 peripheral neuropathy and further BD therapy was discontinued. Peripheral blood stem cells (PBSC) were harvested, but he was followed-up without transplantation due to persistent peripheral neuropathy. Two years later, serum IgG levels were gradually increased, and he was referred to our hospital. Laboratory examination revealed that Hb level was 14.0 g/dl and serum total protein 10.0 g/dl with 36.3% M-protein (3.63 g/dl). Bone marrow was normocellular with 13.2% MM cells. As salvage therapy, he received lenalidomide (25 mg on days 1–21) plus dexamethasone (20 mg on days 2, 9, and 16) therapy on a 28-day cycle, but the dosage and frequency of dexamethasone was reduced because of hypertension and skin acne (Fig. 1a). On day 8 at cycle 1, serum CRP level was suddenly increased to 6.32 mg/dl and decreased to 0.85 mg/dl on day 12 after administration of dexamethasone, but re-elevated to 8.37 mg/dl on day 15. Plasma fibrinogen level was also increased up to 916 mg/dl, but white blood cell count remained normal range. He experienced grade 1 dry skin and fatigue as adverse events, but there were no signs and symptoms of infection or inflammation such as fever and arthralgia. We carefully continued the treatment, and serum CRP and plasma fibrinogen levels became unremarkable during subsequent therapeutic cycles. His serum total protein was gradually decreased to 6.7 g/dl with 11.2% M-protein (0.75 g/dl) achieving PR after 4 cycles of the therapy. Case 2 A 58-year-old male was admitted to our hospital because of compression fracture in lumbar vertebrae. He S. Ozaki (&) T. Harada S. Fujii S. Nakamura H. Miki A. Nakano K. Kagawa K. Takeuchi M. Abe T. Matsumoto Department of Medicine and Bioregulatory Sciences, The University of Tokushima Graduate School of Health Biosciences, 3-18-15 Kuramoto, Tokushima 770-8503, Japan e-mail: ozakishu@clin.med.tokushima-u.ac.jp

High-dose melphalan (200 mg/m2) as conditioning regimen followed by autologous stem cell transplantation (ASCT) rescue has been established as a standard treatment for patients with multiple myeloma (MM) younger than 65 years of age. However, the role of ASCT in elderly patients older than 65 years remains controversial in the era of novel agents such as thalidomide, bortezomib, and lenalidomide. The efficacy and feasibility of ASCT have been shown in elderly patients by reducing the dose of melphalan to 100–140 mg/m2. Although the clinical benefit of reduced-intensity ASCT in elderly patients has not been clearly established in comparison with that of novel agent-based induction therapy, recent studies have demonstrated that sequential strategies of novel agent-based induction therapy and reduced-intensity ASCT followed by consolidation/maintenance with novel agents translate into better outcome in the management of elderly patients. Thus, ASCT could also be a mainstay in the initial treatment of elderly MM patients, and its indication should be evaluated based on performance status and the presence of complications and/or comorbidities of each elderly patient with MM.

Multiple myeloma (MM) is a heterogeneous disease in the survival outcome due to the differences in disease-, patient-, and treatment-related prognostic factors. Recently, a Revised International Staging System (R-ISS) incorporating the original ISS stage, high serum LDH, and adverse cytogenetic abnormalities (CA) such as [t(4;14), t(14;16), or del(17p)] by FISH, which is expected to predict treatment outcome more accurately in the era of novel agents and autologous stem cell transplantation (ASCT), has been proposed. However, it has been noted that more than 60% of myeloma patients are doomed to be classified as R-ISS stage II, which may encompass heterogeneous population in terms of risk factors. In the present study, we have evaluated the clinical relevance of R-ISS in Japanese patients with MM and invented a new prognostic scoring system to minimize the heterogeneity of the R-ISS stage II. Clinical features of the patients diagnosed and treated between 2001 and 2012 by the members of the Japanese Society of Myeloma were collected and assessed for the treatment outcome. Among the individual data obtained from 4138 patients from 38 centers, only those of 718 patients were complete and were further analyzed. A total of 498 patients (69.4%) were treated with conventional chemotherapy with or without novel agents without ASCT, and the remaining 220 patients (30.6%) were treated with ASCT after induction with chemotherapy with or without novel agents. The patient distribution according to R-ISS stages (I/II/III) was 154 (21.4%), 438 (61.1%), and 126 patients (17.5%), respectively, with corresponding median overall survival (OS) being 152.8, 65.2, and 45.3 months, respectively (p=8.98e-15). Although the R-ISS model could discriminate the difference between each stage distinctly in transplant-ineligible patients (median OS: stage I, 90.7; stage II, 57.5; and stage III, 33.1 months, respectively, p=2.37e-12), discrimination of the difference between the stages II and III was ambiguous in transplant-eligible patients (median OS: stage I, not reached; stage II, 71.2; and stage III, 73.8 months, respectively, p=0.0325). In addition, median OS of R-ISS stage II were quite heterogeneous according to the presence or absence of risk factors (high LDH and adverse CA): 74.2 months for ISS stage I with 1 risk factor of either LDH or CA, 34.0 months for ISS stage I with both risk factors, 130.8 months for ISS stage II without risk factors, 53.8 months for ISS stage II with 1 risk factor, 46.9 months for ISS stage II with both risk factors, and 61.8 months for ISS stage III without risk factors. These results would implicate that high LDH and/or adverse CA might exert stronger impact on OS. Accordingly, we performed a multivariate analysis to disclose more important factors that were independently associated with poor prognosis, and identified the following factors: serum albumin (normal upper limit, p Figure 1 Overall survival according to the score. Figure 1. Overall survival according to the score. Disclosures Sunami: Celgene Co. Ltd.: Research Funding; Research funding from Ono Pharmaceutical Co. Ltd., Novartis Pharmaceutical Co. Ltd.: Research Funding; Takeda Pharmaceutical Co. Ltd.: Research Funding; Ono Pharmaceutical Co. Ltd.: Research Funding.

Introduction:Central nervous system invasion in multiple myeloma (CNS-MM) is extremely rare (approximately 1% of MM). Prognosis of patients with CNS-MM is generally poor, and the median overall survival (OS) time from its diagnosis (Dx) has been reported to be 2 to 7 months. However, because of its rareness, most available data concerning CNS-MM are based on anecdotal reports on small case series. In this study, we retrospectively collected clinical data of Japanese patients with CNS-MM and analyzed them to reveal clinical features and prognosis of this disease entity. Methods:We conducted a nationwide multicenter retrospective study involving 107 centers that consist of educational facilities authorized by Japanese Society of Hematology and its related hospitals. CNS-MM was defined based on the previously reported criteria (Br J Haematol 2013;162:483-48). Univariate and multivariate analyses were performed to explore prognostic factors and the suitable treatment of CNS-MM. Results:From December 1978 to February 2016, 75 patients with CNS-MM were identified. The median age was 58 (range: 32-77 years). CNS invasion was detected at initial Dx of MM in 4% and at relapse in 96%. The median time from Dx of MM to that of the secondary CNS-MM was 1.8 years. Concomitant plasma cell leukemia (18%), skull plasmacytoma (12%), and myeloma cells in the cerebrospinal fluid (63%) were observed at the Dx of CNS-MM. Common symptoms of CNS-MM included consciousness disturbance (37%), cranial nerve palsy (25%), diplopia (18%), headache (16%), spinal nerve disorder (13%), and nausea/vomiting (12%). Intrathecal chemotherapy (IT) was used in 37%, cranial and/or spinal irradiation therapies (RTx) in 45% in addition to various systemic therapies, which included immunomodulatory drugs (IMiDs) (21%), bortezomib (19%), alkylators (21%), dexamethasone alone (6%), autologous stem cell transplant (auto-SCT, 4%), and allogeneic stem cell transplant (allo-SCT, 3%). With a median follow-up of 3.4 months from Dx of CNS-MM and of 31.5 months from that of MM, the median OS time from Dx of CNS-MM was only 3.7 months. The median OS times for the 12 untreated and 61 treated patients were 0.2 and 5.1 months, respectively (P < 0.01), suggesting that the patients who did not receive any treatments (Txs) were in a severe condition and their prognoses were extremely poor. In univariate analyses for the entire group, absence of both atypical lymphocytes and plasma cells in the peripheral blood at Dx of MM and no Tx for MM before Dx of CNS-MM were significantly favorable prognostic factors (P = 0.008 and P < 0.0001, respectively). Regarding Tx for CNS-MM patients who received any Txs (conventional chemotherapies, bortezomib, IMiDs, IT, and RTx), only RTx was correlated with longer OS time (P = 0.047). In multivariate analyses, RTx and IT had a significant impact on longer OS time (>6 months, OR = 3.80, 3.97, P = 0.002, 0.01, respectively). Although the prognosis of CNS-MM in this study cohort was very poor, seven patients could survive for >1 year from Dx of CNS-MM. Among them, RTx, IMiDs, IT, bortezomib, auto-SCT, and allo-SCT were given to 5, 4, 5, 3, 1, and 1 patients, respectively. Conclusions:Prognosis of CNS-MM is extremely poor in general. Although there must be a selection bias that patients who received various salvage Txs for CNS-MM were in a better condition, the results of our study suggest that multi-modality Txs with RTx, IT, and IMiDs/bortezomib may prolong the survival time in some cases. Prospective studies are needed to confirm our preliminary observations. Disclosures Takamatsu: Celgene: Honoraria; Janssen Pharmaceuticals: Honoraria. Sunami:Janssen Pharmaceutical: Research Funding; Sanofi: Research Funding; Daiichi Sankyo: Research Funding; Bristol-Myers Squibb K.K.: Research Funding; Novartis: Research Funding; Celgene: Honoraria, Research Funding; Takeda: Research Funding; Ono Pharmaceutical: Research Funding. Hagiwara:Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Kuroda:Janssen: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Astra Zeneca: Research Funding; Celgene: Honoraria, Research Funding. Murakami:Bristol Meyers Squibb: Honoraria; Astellas: Honoraria; Mochida: Honoraria; Eisai: Honoraria; Takeda: Honoraria; MSD: Honoraria; Chugai: Honoraria; Celgene: Honoraria. Nakao:Alexion Pharmaceuticals: Honoraria, Research Funding. Tobinai:Celgene: Research Funding; Mundipharma KK: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; SERVIER: Research Funding; HUYA Bioscience: Honoraria; Kyowa Hakko Kirin: Research Funding; Zenyaku Kogyo: Honoraria; Chugai Pharma: Research Funding; Abbvie: Research Funding; GlaxoSmithKline: Research Funding; Ono Pharmaceutical: Research Funding; Daiichi Sankyo Co., Ltd.: Consultancy; Janssen Pharmaceuticals: Honoraria, Research Funding. Iida:Celgene: Honoraria, Research Funding; Janssen Pharmaceuticals: Honoraria, Research Funding.

A 33-year-old man with a 4-year history of Crohn's disease presented with marked ascites and an abdominal tumor. Two M-protein peaks, immunoglobulin (Ig) G-κ and IgA-κ, were detected in the serum. Neoplastic lymphoplasmacytic cells were infiltrated in the bone marrow and ascites. Histological examination of the abdominal tumor showed marked proliferation of lymphoplasmacytic cells that were positive for either IgG or IgA. Moreover, DNA sequences of the expressed IgG and IgA genes were different in the complementarity-determining region 3. These results suggest that chronic inflammation in Crohn's disease contributes to the simultaneous development of biclonal lymphoplasmacytic immunocytoma of the small intestine.(Internal Medicine 38: 500-503, 1999)

BACKGROUND To develop a new immunologic approach to multiple myeloma, the authors generated a monoclonal antibody against a human plasma cell specific antigen, HM1.24. Their previous study showed the antitumor effect of this antibody in severe combined immunodeficiency (SCID) mice bearing human myeloma xenografts. In the current study, the efficacy of anti-HM1.24 immunoglobulin (Ig) G and its F(ab')2 fragment were evaluated for radioimmunologic detection of the myeloma xenografts. METHODS SCID mice bearing subcutaneous RPMI 8226 tumors were injected with 125I-labeled antibodies, and radioactivity in the tumor and normal tissues was measured. Radioimmunoscintigraphy and autoradiography were performed to investigate the distribution of the antibodies. RESULTS In comparative biodistribution studies, the maximum tumor localization index of anti-HM1.24 F(ab')2 fragment was significantly higher than that of anti-HM1.24 IgG. Anti-HM1.24 F(ab')2 consistently had higher tumor-to-tissue ratio than anti-HM1.24 IgG and gave distinct tumor images by radioimmunoscintigraphy. Autoradiographic study showed that anti-HM1.24 F(ab')2 penetrated the tumor mass more uniformly than whole IgG antibody. CONCLUSIONS These results indicate that anti-HM1.24 antibody has the potential to provide a new approach to the immunodetection and immunotherapy of multiple myeloma and related plasma cell dyscrasias. Cancer 1998;82:2184-2190. © 1998 American Cancer Society.