Phase II Trial of Romidepsin as Consolidation Therapy after Gemcitabine, Dexamethasone, and Cisplatin in Elderly Transplant-Ineligible Patients with Relapsed/Refractory Peripheral T-Cell Lymphoma.

Romidepsin is an important therapeutic option for patients with peripheral T-cell lymphoma (PTCL). However, the timing of romidepsin administration remains controversial. The objective of this study was to characterize the safety and efficacy of romidepsin as consolidation therapy after gemcitabine, dexamethasone, and cisplatin (GDP) therapy (GDPR). This study of patients treated between March 2019 and March 2021 was registered with the Japan Registry of Clinical Trials (registration number: jRCT0000000519). If complete response, partial response, or stable disease was confirmed after 2-4 GDP cycles, romidepsin was administered every 4 weeks for 1 year. Seven patients with relapsed/refractory (R/R) PTCL (T-follicular helper phenotype [n = 1] and angioimmunoblastic T-cell lymphoma [n = 6]) were included in this prospective study (PTCL-GDPR). After a median follow-up of 34 months of patients in PTCL-GDPR, the 2-year overall survival rate was 71%, and the overall response rate after treatment was 57%. Common adverse events in patients with PTCL-GDPR included hematological toxicities such as neutropenia, which improved with supportive treatment. There were no treatment-related mortalities. GDPR might be safe and effective in elderly transplant-ineligible patients with R/R PTCL; however, further investigation is required.

A phase II Japanese trial of 90-minute rituximab infusion for untreated B-cell lymphoma.

OBJECTIVE: This phase II clinical trial evaluated feasibility and tolerability of 90-minute rituximab infusion and a concentration of 4 mg/mL rituximab infusion in Japanese patients with previously untreated follicular lymphoma or diffuse large B-cell lymphoma. METHODS: Treatment was rituximab with cyclophosphamide, doxorubicin, vincristine and prednisolone. In cycle 1, rituximab at a dose of 375 mg/m2 (4 mg/mL) was administered at the standard infusion rate stipulated in the package insert. On confirmed tolerance of rituximab, patients received 90-minute infusion in second and subsequent cycles. The primary endpoint was incidence of grade 3 or higher infusion-related reactions during 90-minute rituximab infusion in cycle 2 of rituximab with cyclophosphamide, doxorubicin, vincristine and prednisolone. RESULTS: All 32 patients (median age 61.5 years, 16 males, 24 with diffuse large B-cell lymphoma) completed the prescribed six or eight cycles of treatment. One patient withdrew consent after cycle 1, and another developed grade 2 erythema and continued receiving 4 mg/mL at the standard infusion rate for cycle 2. The remaining 30 patients received 90-minute rituximab infusion; 28 (93.3%) completed cycle 2 at the scheduled infusion rate and dosage. No grade 3 or higher infusion-related reactions were associated with a concentration of 4 mg/mL rituximab dose or 90-min rituximab infusion in cycle 2. The most common infusion-related reaction symptoms were pruritus, hypertension and oropharyngeal discomfort. During the study, toxicities and adverse events were as expected, with no new safety signals. CONCLUSION: High-concentration dosing (4 mg/mL) and 90-minute infusion of rituximab are feasible and tolerable in Japanese patients with previously untreated follicular lymphoma or diffuse large B-cell lymphoma. CLINICAL TRIAL NUMBER: JapicCTI-173 663.

A phase 2, open-label, multicenter study of ixazomib plus lenalidomide and dexamethasone in adult Japanese patients with relapsed and/or refractory multiple myeloma.

BACKGROUND: TOURMALINE-MM1 was a global study that demonstrated a significant improvement in progression-free survival with ixazomib plus lenalidomide and dexamethasone compared with placebo plus lenalidomide and dexamethasone, in patients with relapsed and/or refractory multiple myeloma. The current study was conducted to evaluate further the efficacy and safety of ixazomib plus lenalidomide and dexamethasone in Japanese patients. METHODS: This phase 2, open-label, single-arm, multicenter study enrolled patients aged ≥ 20 years with relapsed and/or refractory multiple myeloma at 16 sites in Japan. Patients refractory to lenalidomide or proteasome inhibitor-based therapy at any line were excluded. The primary endpoint was the rate of very good partial response or better in the response-evaluable analysis set. Secondary endpoints were progression-free survival, overall response rate, duration of response, time to progression, overall survival and safety. RESULTS: In total, 34 patients were enrolled. The rate of very good partial response or better was 50.0% (95% confidence interval 31.9-68.1) and the overall response rate was 84.4% (95% confidence interval 67.2-94.7). Median progression-free survival was 22.0 months (95% confidence interval 17.3-not evaluable) and median overall survival was not estimable. The safety profile of ixazomib plus lenalidomide and dexamethasone in this study was similar to that in the TOURMALINE-MM1 study. CONCLUSIONS: The efficacy and safety of ixazomib plus lenalidomide and dexamethasone in Japanese patients with relapsed and/or refractory multiple myeloma are comparable with reported TOURMALINE-MM1 study results. CLINICALTRIALS. GOV IDENTIFIER: NCT02917941; date of registration September 28, 2016.

Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone combined with high-dose methotrexate plus intrathecal chemotherapy for newly diagnosed intravascular large B-cell lymphoma (PRIMEUR-IVL): a multicentre, single-arm, phase 2 trial.

BACKGROUND: Intravascular large B-cell lymphoma (IVLBCL) is a rare disease for which there is no available standard treatment. We aimed to ascertain the safety and activity of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) with high-dose methotrexate and intrathecal chemotherapy as CNS-oriented therapy for patients with previously untreated IVLBCL. METHODS: PRIMEUR-IVL is a multicentre, single-arm, phase 2 trial at 22 hospitals in Japan. Eligible patients had untreated histologically confirmed IVLBCL, were aged 20-79 years, had an Eastern Cooperative Group performance status of 0-3, and had no apparent CNS involvement at diagnosis. Patients received three cycles of R-CHOP (rituximab 375 mg/m2 intravenously on day 1 [except cycle one, which was on day 8]; cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, and vincristine 1·4 mg/m2 [maximum 2·0 mg] intravenously on day 1 of cycle one and day 2 of cycles two and three; and prednisolone 100 mg/day orally on days 1-5 of cycle one and days 2-6 of cycles two and three) followed by two cycles of rituximab with high-dose methotrexate (3·5 g/m2 intravenously on day 2 of cycles four and five) every 2 weeks and three additional cycles of R-CHOP. Intrathecal chemotherapy (methotrexate 15 mg, cytarabine 40 mg, and prednisolone 10 mg) was administered four times during the R-CHOP phase. The primary endpoint was 2-year progression-free survival. Efficacy analyses were done in all enrolled patients; safety analyses were done in all enrolled and treated patients. The trial is registered in the UMIN Clinical Trials Registry (UMIN000005707) and the Japan Registry of Clinical Trials (jRCTs041180165); the trial is ongoing for long-term follow-up. FINDINGS: Between June 16, 2011, and July 21, 2016, 38 patients were enrolled, of whom 37 were eligible; one patient was excluded because of a history of testicular lymphoma. Median follow-up was 3·9 years (IQR 2·5-5·5). 2-year progression-free survival was 76% (95% CI 58-87). The most frequent adverse events of grade 3-4 were neutropenia and leucocytopenia, which were reported in all 38 (100%) patients. Serious adverse events were hypokalaemia, febrile neutropenia with hypotension, hypertension, and intracerebral haemorrhage (reported in one [3%] patient each). No treatment-related deaths occurred during protocol treatment. INTERPRETATION: R-CHOP combined with rituximab and high-dose methotrexate plus intrathecal chemotherapy is a safe and active treatment for patients with IVLBCL without apparent CNS involvement at diagnosis, and this regimen warrants future investigation. FUNDING: The Japan Agency for Medical Research and Development, the Center for Supporting Hematology-Oncology Trials, and the National Cancer Center.

Soluble SLAMF7 promotes the growth of myeloma cells via homophilic interaction with surface SLAMF7.

SLAMF7 is expressed mainly on multiple myeloma (MM) cells and considered an ideal target for immunotherapeutic approaches. Indeed, elotuzumab, an anti-SLAMF7 antibody, is used for the treatment of MM in combination with immunomodulatory drugs. SLAMF7 is cleaved via unknown mechanisms and detected as a soluble form (sSLAMF7) exclusively in the serum of MM patients; however, little is known about the role of sSLAMF7 in MM biology. In this study, we found that sSLAMF7 enhanced the growth of MM cells via homophilic interaction with surface SLAMF7 and subsequent activation of the SHP-2 and ERK signaling pathways. Elotuzumab suppressed sSLAMF7-induced MM cell growth both in vitro and in vivo. Promoter analyses identified IKZF1 (Ikaros) as a pivotal transcriptional activator of the SLAMF7 gene. Pharmacological targeting of Ikaros by lenalidomide and its analog pomalidomide downregulated SLAMF7 expression and ameliorated the response of MM cells to sSLAMF7. Elotuzumab blocked the growth-promoting function of sSLAMF7 when combined with lenalidomide in a murine xenograft model. Neutralization of sSLAMF7 is a novel antimyeloma mechanism of elotuzumab, which is enhanced by immunomodulatory drugs via downregulation of surface SLAMF7 expression on MM cells. These findings may provide important information for the optimal use of elotuzumab in MM treatment.

Final results of a phase I study of carfilzomib, lenalidomide, and dexamethasone for heavily pretreated multiple myeloma.

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).

A phase II study of lenalidomide consolidation and maintenance therapy after autologous PBSCT in patients with multiple myeloma.

The efficacy and safety of lenalidomide (LEN) consolidation therapy and subsequent LEN maintenance therapy after high-dose therapy with autologous peripheral blood stem cell transplantation (auto-PBSCT) were evaluated in patients with newly diagnosed symptomatic multiple myeloma (MM). Forty-one patients were enrolled and received high-dose dexamethasone (DEX) therapy as an initial induction. The patients who did not respond to the DEX therapy were further treated with four cycles of bortezomib plus DEX (BD) induction therapy. For patients who responded to BD, PBSC harvesting was scheduled following high-dose cyclophosphamide and filgrastim administration. After PBSC harvesting, high-dose chemotherapy of melphalan with auto-PBSCT was performed. One hundred days after auto-PBSCT, patients received consolidation therapy consisting two cycles of LEN plus low-dose DEX (Ld) and LEN maintenance therapy. Only one death occurred during mobilization therapy, but the protocol developed in this study was considered generally safe to provide. Overall response rates after consolidation and maintenance therapies were 73.7% and 81.6%, respectively. Two-year progression-free survival and overall survival were 76.3% and 92.1%, respectively. These observations suggest that LEN consolidation and maintenance therapy are effective and safe, and provide favorable response rates in patients with MM.

Prognostic impact of serum soluble interleukin-2 receptor level at diagnosis in elderly patients with diffuse large B-cell lymphoma treated with R-CHOP.

Diffuse large B-cell lymphoma (DLBCL) is a clinically heterogeneous disease. To evaluate the clinical relevance of the serum soluble interleukin-2 receptor (sIL-2R) level, we retrospectively analyzed 178 patients aged ≥60 years who were newly diagnosed with DLBCL. We determined the cutoff value of the sIL-2R level to be 1280 U/mL using the area under the receiver operating characteristic curve. The high sIL-2R group exhibited significantly inferior 5-year progression-free survival (PFS) (36.2% vs. 86.1%, p < .001) and 5-year overall survival (OS) (49.7% s. 83.8%, p < .001) than the low sIL-2R group. Multivariate analysis revealed that a high sIL-2R level was a significant prognostic factor for PFS and OS (hazard ratio [HR]: 5.65, p < .001 and HR: 2.99, p = .001, respectively). This study showed that measurement of the sIL-2R level at diagnosis is clinically beneficial for identifying elderly patients with DLBCL who have a poor prognosis.

Correction to: A phase II study of lenalidomide consolidation and maintenance therapy after autologous PBSCT in patients with multiple myeloma.

In the original publication of this article, "Conflict of interest" was published incorrectly. The corrected "Conflict of interest" is given below for your reading.

[Safety and management of adverse events of ixazomib/lenalidomide/dexamethasone therapy in Japanese patients with relapsed/refractory multiple myeloma].

Based on the outcomes of the TOURMALINE-MM1 trial-a global, randomized, double-blind, placebo-controlled phase III clinical study-the use of an oral proteasome inhibitor has been approved in combination with lenalidomide and dexamethasone (Rd) for the treatment of relapsed/refractory multiple myeloma (MM). In this study, we enrolled 41 Japanese patients, who constituted the safety population. The overall incidence of adverse events (AEs) was similar in IRd and placebo-Rd groups. AEs including thrombocytopenia, skin disorders (rash), vomiting, nausea, and diarrhea occurred more frequently in the IRd group than in the placebo-Rd group. There were no cumulative toxicities, and most toxicities were usually manageable with close monitoring, supportive care, and dose modifications. Compared with the overall safety population, the safety profile of Japanese patients was consistent. Moreover, in Japanese patients, there were no on-study deaths and the incidence of serious AEs was less frequent.

Patient-reported health-related quality of life from the phase III TOURMALINE-MM1 study of ixazomib-lenalidomide-dexamethasone versus placebo-lenalidomide-dexamethasone in relapsed/refractory multiple myeloma.

TOURMALINE-MM1 is a phase III, randomized, double-blind, placebo-controlled study of ixazomib plus lenalidomide and dexamethasone (IRd) versus placebo-Rd in patients with relapsed/refractory multiple myeloma following 1-3 prior lines of therapy. The study met its primary endpoint, demonstrating significantly longer progression-free survival (PFS) in the IRd arm versus placebo-Rd arm (median 20.6 vs 14.7 months, hazard ratio 0.74, P = .01), with limited additional toxicity. Patient-reported health-related quality of life (HRQoL) was a secondary endpoint of TOURMALINE-MM1. The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core-30 (QLQ-C30) and Multiple Myeloma Module 20 (QLQ-MY20) were completed at screening, the start of cycles 1 and 2, every other cycle, the end of treatment, and every 4 weeks until progression. Over median follow-up of 23.3 and 22.9 months in the IRd and placebo-Rd arms, mean QLQ-C30 global health status (GHS)/QoL scores were maintained from baseline over the course of treatment in both groups, with no statistically significant differences between groups. EORTC QLQ-C30 function domain scores were also generally maintained from baseline; similarly, physical, emotional, and social function domains were maintained with IRd versus placebo-Rd, with slightly higher mean change from baseline scores at earlier time points with IRd. Findings from this double-blind study demonstrate that addition of ixazomib to Rd significantly improved efficacy while HRQoL was maintained, reflecting the limited additional toxicity seen with IRd versus placebo-Rd, and support the feasibility of long-term IRd administration.

Myeloma Cells Are Activated in Bone Marrow Microenvironment by the CD180/MD-1 Complex, Which Senses Lipopolysaccharide.

Multiple myeloma (MM) cells acquire dormancy and drug resistance via interaction with bone marrow stroma cells (BMSC) in a hypoxic microenvironment. Elucidating the mechanisms underlying the regrowth of dormant clones may contribute to further improvement of the prognosis of MM patients. In this study, we find that the CD180/MD-1 complex, a noncanonical lipopolysaccharide (LPS) receptor, is expressed on MM cells but not on normal counterparts, and its abundance is markedly upregulated under adherent and hypoxic conditions. Bacterial LPS and anti-CD180 antibody, but not other Toll-like receptor ligands, enhanced the growth of MM cells via activation of MAP kinases ERK and JNK in positive correlation with expression levels of CD180. Administration of LPS significantly increased the number of CD180/CD138 double-positive cells in a murine xenograft model when MM cells were inoculated with direct attachment to BMSC. Knockdown of CD180 canceled the LPS response in vitro and in vivo Promoter analyses identified IKZF1 (Ikaros) as a pivotal transcriptional activator of the CD180 gene. Both cell adhesion and hypoxia activated transcription of the CD180 gene by increasing Ikaros expression and its binding to the promoter region. Pharmacological targeting of Ikaros by the immunomodulatory drug lenalidomide ameliorated the response of MM cells to LPS in a CD180-dependent manner in vitro and in vivo Thus, the CD180/MD-1 pathway may represent a novel mechanism of growth regulation of MM cells in a BM milieu and may be a therapeutic target of preventing the regrowth of dormant MM cells.Significance: This study describes a novel mechanism by which myeloma cells are regulated in the bone marrow, where drug resistance and dormancy can evolve after treatment, with potential therapeutic implications for treating this often untreatable blood cancer. Cancer Res; 78(7); 1766-78. ©2018 AACR.

Carfilzomib, lenalidomide and dexamethasone in patients with heavily pretreated multiple myeloma: A phase 1 study in Japan.

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.

Bendamustine plus rituximab for previously untreated patients with indolent B-cell non-Hodgkin lymphoma or mantle cell lymphoma: a multicenter Phase II clinical trial in Japan.

A Phase II, multicenter clinical trial of bendamustine plus rituximab (BR) regimen was conducted in previously untreated patients with high-tumor-burden indolent B-cell non-Hodgkin lymphoma (B-NHL) and previously untreated elderly patients with mantle cell lymphoma (MCL) in Japan. Bendamustine 90 mg/m2/day on days 1 and 2, as well as rituximab 375 mg/m2 on day 1 were administered intravenously up to six cycles. The primary endpoint was the complete response (CR) rate as assessed by the International Workshop Response Criteria (1999). Sixty-nine patients (59 with indolent B-NHL and 10 with MCL) were treated. The median number of delivered cycles was six (range 1-6). The CR rates were 67.8% [95% confidence interval (CI) 54.4-79.4%] and 70.0% (95% CI 34.8-93.3%) for indolent B-NHL and MCL, respectively. Estimated progression-free survival at 30 months was 72.1% (95% CI 58.5-82.0%) in indolent B-NHL and was 67.5% (95% CI 29.1-88.2%) in MCL. Major grade 3/4 toxicities were hematologic and included lymphopenia (97%), CD4 lymphopenia (91%), neutropenia (86%), and leukopenia (83%). No treatment-related death was found. The BR regimen showed high efficacy as evidenced by the expected CR rate and durable response, as well as an acceptable safety profile for the study populations.

Phosphorylation-mediated EZH2 inactivation promotes drug resistance in multiple myeloma.

Alterations in chromatin modifications, such as histone methylation, have been suggested as mediating chemotherapy resistance in several cancer types; therefore, elucidation of the epigenetic mechanisms that underlie drug resistance may greatly contribute to the advancement of cancer therapies. In the present study, we identified histone H3-lysine 27 (H3K27) as a critical residue for epigenetic modification in multiple myeloma. We determined that abrogation of drug-induced H3K27 hypermethylation is associated with cell adhesion-mediated drug resistance (CAM-DR), which is the most important form of drug resistance, using a coculture system to evaluate stroma cell adhesion-dependent alterations in multiple myeloma cells. Cell adhesion counteracted anticancer drug-induced hypermethylation of H3K27 via inactivating phosphorylation of the transcription regulator EZH2 at serine 21, leading to the sustained expression of antiapoptotic genes, including IGF1, B cell CLL/lymphoma 2 (BCL2), and hypoxia inducible factor 1, α subunit (HIF1A). Pharmacological and genetic inhibition of the IGF-1R/PI3K/AKT pathway reversed CAM-DR by promoting EZH2 dephosphorylation and H3K27 hypermethylation both in vitro and in refractory murine myeloma models. Together, our findings identify and characterize an epigenetic mechanism that underlies CAM-DR and suggest that kinase inhibitors to counteract EZH2 phosphorylation should be included in combination chemotherapy to increase therapeutic index.

Can serum albumin level affect the pharmacological action of tolvaptan in patients with liver cirrhosis? A post hoc analysis of previous clinical trials in Japan.

BACKGROUND: Patients with hypoalbuminemia often fail to respond to increased doses of loop diuretics. We therefore performed a post hoc analysis to investigate the pharmacological action of tolvaptan and whether it is dependent on the serum albumin level. METHODS: This analysis was based on four previous clinical trials of tolvaptan in patients with liver cirrhosis who exhibited insufficient response to conventional diuretics. We analyzed the correlation between the change in the initial 24-h cumulative urine volume from baseline and the serum albumin level at baseline, and assessed potential predictive factors of response to tolvaptan. RESULTS: The correlation coefficient was 0.029 in the placebo group and -0.112 in the 7.5 mg tolvaptan group of patients with liver cirrhosis. Administration of tolvaptan provoked a stable response regardless of the serum albumin level. Tolvaptan use was identified as a significant predictor of pharmacological action, and was shown to change the initial urine volume by 885 mL (P < 0.0001) in liver cirrhosis patients. CONCLUSIONS: In this post hoc analysis, tolvaptan increased the initial urine volume from baseline regardless of serum albumin levels. Use of tolvaptan as an add-on therapy to loop diuretics can be considered an optimal therapeutic option in patients with insufficient response to loop diuretics.

[Novel targeted therapy in multiple myeloma].

Recently, new agents have explored in the treatment of multiple myeloma (MM), according to the identification of the novel pathogenetic mechanisms. Proteasome inhibitor (bortezomib) and immunomodulatory drugs (thalidomide and lenalidomide) now play important roles in the treatment of MM, and they have resulted in an improvement of the outcome of the patients. However, MM remains incurable and the prognosis is very poor in the patients who become refractory to bortezomib and IMiDs. New agents with novel mechanism of action in MM (monoclonal antibodies, deacetylase inhibitors, and so on) will be discussed in this review.

Baseline cardiac magnetic resonance imaging versus baseline endomyocardial biopsy for the prediction of left ventricular reverse remodeling and prognosis in response to therapy in patients with idiopathic dilated cardiomyopathy.

Endomyocardial biopsy (EMB) and late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging performed at baseline are both used to evaluate the extent of myocardial fibrosis. However, no study has directly compared the effectiveness of these diagnostic tools in the prediction of left ventricular reverse remodeling (LVRR) and prognosis in response to therapy in patients with idiopathic dilated cardiomyopathy (IDCM). Seventy-five patients with newly diagnosed IDCM who were undergoing optimal therapy were assessed at baseline using LGE-CMR imaging and EMB; the former measured LGE area and the latter measured collagen volume fraction (CVF) as possible predictive indices of LVRR and cardiac event-free survival. Among all the baseline primary candidate factors with P < 0.2 as per univariate analysis, multivariate analysis indicated that only LGE area was an independent predictor of subsequent LVRR (ß = 0.44; 95 % confidence interval (CI) 0.87-2.53; P < 0.001), as indicated by decreasing left ventricular end-systolic volume index over the 1-year follow-up. Kaplan-Meier curves indicated significantly lower cardiac event-free survival rates in patients with LGE at baseline than in patients without (P < 0.01). By contrast, there was no significant difference in prognosis between patients with CVF values above (severe fibrosis) and below (mild fibrosis) the median of 4.9 %. Cox proportional hazard analysis showed that LGE area was an independent predictor of subsequent cardiac events (hazard ratio 1.06; 95 % CI 1.02-1.10; P ≤ 0.01). The degree of myocardial fibrosis estimated by baseline LGE-CMR imaging, but not that estimated by baseline EMB, can predict LVRR and cardiac event-free survival in response to therapy in patients with newly diagnosed IDCM.