BACKGROUND: Primary results from the EPCORE NHL-3 trial (NCT04542824) showed deep, durable responses in Japanese patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) treated with single-agent epcoritamab, a subcutaneous CD3xCD20 bispecific antibody. Here, we report 3-year follow-up of safety and efficacy. METHODS: Japanese patients with R/R CD20+ DLBCL and  ≥ 2 prior systemic therapies received epcoritamab (0.16/0.8-mg step-up doses, then 48-mg full doses) according to the approved label. The primary endpoint was overall response rate per independent review committee. RESULTS: As of July 12, 2024, 36 patients received epcoritamab (median follow-up, 36.7 months). Overall/complete response rates were 56%/47%. Median duration of response was 15.2 months. Median duration of complete response was not reached; an estimated 53% of complete responders remained in complete response at 3 years. Median progression-free/overall survival (PFS/OS) were 4.1/14.9 months overall; neither was reached among complete responders. Three-year PFS/OS estimates were 25%/39% overall and 53%/71% in complete responders. Among 30 evaluable patients, 17 (57%) became minimal residual disease (MRD) negative, which was associated with longer PFS (cycle 3 day 1 landmark analysis). The most common treatment-emergent adverse events (TEAEs) were cytokine release syndrome (83%), injection-site reaction (69%), and neutropenia (39%), consistent with previous reports. No fatal TEAEs occurred. CONCLUSIONS: With  > 3 years of follow-up, epcoritamab treatment has consistently shown durable responses and high rates of MRD negativity in Japanese patients with R/R DLBCL. Safety was similar to previous reports. These long-term remissions reaffirm encouraging outcomes with epcoritamab for this challenging-to-treat population.

An unmet need exists for patients with relapsed or refractory (R/R) follicular lymphoma (FL) whose disease remains incurable. Epcoritamab, a subcutaneous CD3xCD20 bispecific antibody, is approved for R/R FL and different types of R/R large B-cell lymphoma after ≥2 prior lines of therapy (pLOT) in the US, Europe, and Japan. Regional data are critical to contextualize global trial data. In the Japan-specific EPCORE NHL-3 trial (phase 1/2), 21 adults with R/R FL and ≥2 pLOT received subcutaneous epcoritamab (two step-up doses, then 48-mg full doses) until progression. Median follow-up was 21.2 months. Responses were frequent and deep (overall response rate, 95.2%; complete response rate, 76.2%), including in high-risk subgroups, as well as durable. Safety was manageable; cytokine release syndrome events had predictable timing and were mostly low grade, and no fatal treatment-emergent adverse events occurred. These results support epcoritamab as a new treatment option for Japanese patients with R/R FL.Clinical trial registration numbers: NCT04542824; JapicCTI-205408; jRCT2080225312.

Abstract Despite the introduction of new drugs, multiple myeloma (MM) still remains incurable. We previously reported that CD34⁺ MM cells, which are clonogenic and self-renewing, are therapy-resistant and persist as a major component of minimal residual disease, expanding during relapse. To investigate the effects of immunotherapies such as immune-checkpoint inhibitors, CAR-T therapy, and bispecific antibodies on CD34⁺ MM cells, we analyzed immune profiles of both MM cells and T cells from MM patients using microarrays and flow cytometry. Ingenuity pathway analysis revealed 14 out of 289 canonical pathways were more active in CD34⁺ MM cells compared to CD34⁻ cells, many of which were involved in inflammation and immune responses. Notably, PD-1 signaling-related genes were highly expressed in CD34⁺ MM cells. Among 10 immune-checkpoint molecules, CD34⁺ cells more frequently expressed CD112, CD137L, CD270, CD275, and GAL9 than CD34⁻ cells in both newly diagnosed and relapsed/resistant patients. In addition, CD4⁺ and CD8⁺ T cells more frequently expressed TIGIT and CD137, suggesting that CD112/TIGIT and CD137L/CD137 interactions may suppress T-cell activity against CD34⁺ MM cells. Furthermore, our finding of higher FcRH5 expression on CD34⁺ MM cells is encouraging for future research into the efficacy of FcRH5-targeted therapy in MM.

Epcoritamab is a subcutaneously administered CD3xCD20 bispecific Ab that showed deep, durable responses with a manageable safety profile in patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) in the global multicenter pivotal phase II trial EPCORE NHL-1. Here, we present results from the similar EPCORE NHL-3 phase I/II trial evaluating epcoritamab monotherapy in Japanese patients with R/R CD20+ B-cell non-Hodgkin's lymphoma previously treated with two or more lines of therapy. Epcoritamab was dosed subcutaneously in 28-day cycles; once weekly during cycles 1-3, every 2 weeks during cycles 4-9, and every 4 weeks from cycle 10 until disease progression or unacceptable toxicity. Step-up dosing and cytokine release syndrome (CRS) prophylaxis were used during treatment cycle 1. As of January 31, 2022, 36 patients received treatment with 48 mg epcoritamab monotherapy. At a median follow-up of 8.4 months, overall response and complete response rates by independent review committee were 55.6% and 44.4%, respectively. The median duration of response, duration of complete response, and overall survival were not reached at the time of data cut-off. The most common treatment-emergent adverse events of any grade were CRS (83.3%), injection-site reactions (69.4%), infections (44.4%), neutropenia (38.9%), hypokalemia (27.8%), and decreased lymphocyte count (25.0%). Cytokine release syndrome occurrence was predictable; events were primarily low grade (grade 1-2), all resolved, and none led to treatment discontinuation. These encouraging results are consistent with previous findings and support the ongoing clinical evaluation of epcoritamab for the treatment of R/R DLBCL, including in earlier treatment lines.

We retrospectively evaluated long-term outcomes of high dose chemotherapy followed by autologous stem cell transplant (HDC/ASCT) in patients with diffuse large B-cell lymphoma (DLBCL). Between 2004 and 2020, 46 DLBCL patients received HDC/ASCT in our institution, including 12 patients (26.1%), who received as an upfront setting (UFS). At a median follow-up time of 69 months (range, 2-169 months), the 5-year progression-free survival (PFS) rates were 82.5% (95%CI, 46.1-95.3%) in the UFS, and 57.8% (95%CI, 38.1-73.2%) in the relapsed or refractory (R/R) patients (n=34), respectively. The 5-year PFS rates were 62.3% (95%CI, 34.0-81.3%) in primary resistant (n=13) or early relapsing (within 1 year from the initial diagnosis) patients (n=4), and 53.3% (95%CI, 25.9-74.6%) in those relapsing >1 year after the initial diagnosis (n=17), with no statistically significant difference (p=0.498). In R/R patients, multivariate analysis showed that the remission status before HDC/ASCT was an independent poor prognostic factor for progression-free survival (hazard ratio [HR], 17.0; 95%CI, 3.35-86.6; p=0.000630) and high-risk category in the international prognostic index for OS (HR, 9.39; 95%CI, 1.71-51.6; p=0.0100). The incidence of non-relapse mortality by 5 years, and 10 years were 12.2%, and 15.2%, respectively. Eleven patients (23.9%) developed second malignancies, which was the most frequent late complication after HDC/ASCT, with 5-year, and 10-year cumulative incidence of 16.9%, 22.5%, respectively. In conclusion, HDC/ASCT is effective for chemo-sensitive R/R DLBCL regardless of the timing and lines of therapy. However, careful observation is required, considering the long-term complications such as secondary malignancies.

We previously reported that the antipsychotic drug chlorpromazine (CPZ), which inhibits the formation of clathrin-coated vesicles (CCVs) essential for endocytosis and intracellular transport of receptor tyrosine kinase (RTK), inhibits the growth/survival of acute myeloid leukemia cells with mutated RTK (KIT D816V or FLT3-ITD) by perturbing the intracellular localization of these molecules. Here, we examined whether these findings are applicable to epidermal growth factor receptor (EGFR). CPZ dose-dependently inhibited the growth/survival of the non-small cell lung cancer (NSCLC) cell line, PC9 harboring an EGFR-activating (EGFR exon 19 deletion). In addition, CPZ not only suppressed the growth/survival of gefitinib (GEF)-resistant PC9ZD cells harboring T790 M, but also restored their sensitivities to GEF. Furthermore, CPZ overcame GEF resistance caused by Met amplification in HCC827GR cells. As for the mechanism of CPZ-induced growth suppression, we found that although CPZ hardly influenced the phosphorylation of EGFR, it effectively reduced the phosphorylation of ERK and AKT. When utilized in combination with trametinib (a MEK inhibitor), dabrafenib (an RAF inhibitor), and everolimus (an mTOR inhibitor), CPZ suppressed the growth of PC9ZD cells cooperatively with everolimus but not with trametinib or dabrafenib. Immunofluorescent staining revealed that EGFR shows a perinuclear pattern and was intensely colocalized with the late endosome marker, Rab11. However, after CPZ treatment, EGFR was unevenly distributed in the cells, and colocalization with the early endosome marker Rab5 and EEA1 became more apparent, indicating that CPZ disrupted the intracellular transport of EGFR. These results suggest that CPZ has therapeutic potential for NSCLC with mutated EGFR by a novel mechanism different from conventional TKIs alone or in combination with other agents.

C-type lectin-like receptor 2 (CLEC-2) expressed on megakaryocytes plays important roles in megakaryopoiesis. We found that CLEC-2 was expressed in about 20% of phenotypical long-term hematopoietic stem cells (LT-HSCs), which expressed lower levels of HSC-specific genes and produced larger amounts of megakaryocyte-related molecules than CLEC-2low LT-HSCs. Although CLEC-2high LT-HSCs had immature clonogenic activity, cultured CLEC-2high LT-HSCs preferentially differentiated into megakaryocytes. CLEC-2high HSCs yielded 6.8 times more megakaryocyte progenitors (MkPs) and 6.0 times more platelets 2 weeks and 1 week after transplantation compared with CLEC-2low LT-HSCs. However, platelet yield from CLEC-2high HSCs gradually declined with the loss of MkPs, while CLEC-2low HSCs self-renewed long-term, indicating that CLEC-2high LT-HSCs mainly contribute to early megakaryopoiesis. Treatment with pI:C and LPS increased the proportion of CLEC-2high LT-HSCs within LT-HSCs. Almost all CLEC-2low LT-HSCs were in the G0 phase and barely responded to pI:C. In contrast, 54% of CLEC-2high LT-HSCs were in G0, and pI:C treatment obliged CLEC-2high LT-HSCs to enter the cell cycle and differentiate into megakaryocytes, indicating that CLEC-2high LT-HSCs are primed for cell cycle entry and rapidly yield platelets in response to inflammatory stress. In conclusion, CLEC-2high LT-HSCs appear to act as a reserve for emergent platelet production under stress conditions.

We previously examined the utility of rituximab-bendamustine (RB) in patients with follicular lymphoma (FL) exhibiting less than optimal responses to 2 cycles of the R-CHOP chemotherapy regimen. The aim of this study was to identify molecular biomarkers that can predict prognosis in RB-treated patients in the context of the prospective cohort. We first analyzed the mutational status of 410 genes in diagnostic tumor specimens by target capture and Sanger sequencing. CREBBP, KMT2D, MEF2B, BCL2, EZH2, and CARD11 were recurrently mutated as reported before, however none was predictive for progression-free survival (PFS) in the RB-treated patients (n = 34). A gene expression analysis by nCounter including 800 genes associated with carcinogenesis and/or the immune response showed that expression levels of CD8+ T-cell markers and half of the genes regulating Th1 and Th2 responses were significantly lower in progression of disease within the 24-mo (POD24) group (n = 8) than in the no POD24 group (n = 31). Collectively, we selected 10 genes (TBX21, CXCR3, CCR4, CD8A, CD8B, GZMM, FLT3LG, CD3E, EOMES, GZMK), and generated an immune infiltration score (IIS) for predicting PFS using principal component analysis, which dichotomized the RB-treated patients into immune IIShigh (n = 19) and IISlow (n = 20) groups. The 3-y PFS rate was significantly lower in the IISlow group than in the IIShigh group (50.0% [95% CI: 27.1-69.2%] vs. 84.2% [95% CI: 58.7-94.6%], P = .0237). Furthermore, the IIS was correlates with absolute lymphocyte counts at diagnosis (r = 0.460, P = .00355). These results suggest that the T-cell-associated immune markers could be useful to predict prognosis in RB-treated FL patients. (UMIN:000 013 795, jRCT:051 180 181).

The aim of this trial is to evaluate the utility of rituximab-bendamustine (R-B) for untreated advanced follicular lymphoma (FL) showing non-optimal response (nOR) to R-CHOP, and to identify clinical prognostic factors for FL patients receiving R-B. Patients who failed to achieve complete response/complete response unconfirmed (CR/CRu) [nOR-group] after 2 cycles of R-CHOP subsequently received 6 cycles of R-B. The primary endpoint was the 3-year progression-free survival (PFS) rate. Secondary endpoints included determination of prognostic factors. Fifty-six patients initially received R-CHOP, 43/56 patients (76.8%) were judged as nOR, and 33/43 patients (76.7%) completed 6 cycles of R-B. At a median follow-up of 50.6 months in the nOR-group, the 3-year PFS rate was 69.0%, and the 3-year overall survival (OS) rate was 92.7%. The most common toxicities associated with R-B were grade 3-4 lymphopenia (93.0%) and neutropenia (74.4%), both of which were manageable. A multivariate analysis including dose intensity, serum soluble interleukin-2 receptor, and FL international prognostic index-2 revealed low absolute lymphocyte count (<  869/μL) at diagnosis was an independent poor prognostic factor for both PFS and OS in the R-B-treated nOR-group. This result was further confirmed in validation cohorts including R-B-treated de novo (n = 40) and relapsed (n = 49) FL patients.

Acute myeloid leukemia (AML) is a heterogeneous disease often associated with poor prognosis. We previously showed that the localization of KIT-D816V at endolysosomes is critical to activate aberrant Akt signaling and Chlorpromazine (CPZ) perturbs the intracellular localization, leading to cell death in AML cells with KIT-D816V. We report that daily administration of CPZ, prescribed for controlling anxiety disorder in patient with AML harboring KIT-D816V, led to a dramatic reduction in AML cells. In vitro and in vivo experiments showed that CPZ inhibited the growth and survival of the patient-derived AML cells, implying potent efficacy of CPZ in AML with KIT-D816V.

We recently treated a chronic myeloid leukemia (CML) patient with liver and renal dysfunction, who was undergoing hemodialysis (HD). He was treated with 50 mg dasatinib (DAS) once daily just before HD. The maximum plasma concentration of DAS was 227 ng/mL on a non-HD day and 46.9 ng/mL on a HD day. He was subsequently treated with 200 mg bosutinib (BOS) once daily. The plasma concentration of BOS changed from 74.5 ng/mL before HD to 58.8 ng/mL after HD. Our results indicate that close monitoring of the plasma tyrosine kinase inhibitor concentrations should be considered in CML patients with organ impairment.