Recent advances and future perspectives of T-cell engagers in lymphoid malignancies.

Bispecific antibodies (BsAbs) are monoclonal antibodies that simultaneously bind to a specific antigen on tumors and CD3 on T cells, leading to T cell activation and subsequent tumor cell lysis. Several CD20 × CD3 BsAbs are being developed for B-cell lymphomas. Furthermore, multiple clinical trials to evaluate BsAbs for the treatment of multiple myeloma, with targets including BCMA, GPRC5D and FcRH5, are ongoing. Emerging evidence suggests promising efficacy in heavily pretreated patients with relapsed or refractory lymphoid malignancies, showing an overall response rate of 50-60%, with complete response rates of 30-40% for relapsed or refractory large B-cell lymphoma and 60-70% for relapsed or refractory multiple myeloma. Their toxicity profiles are generally consistent with other T-cell redirecting therapies, including cytokine release syndrome, which may be mitigated with several strategies, such as step-up dosing, pre-mediation with glucocorticoids and a subcutaneous route of administration, and very rare neurotoxicity. Several clinical trials evaluated BsAbs in combination with other agents or in earlier lines of treatment, including in front-line settings. BsAbs have the potential to change the treatment paradigm of lymphoid malignancies in the coming years; however, longer follow-ups are required to assess the durability of responses to these agents. We herein provide an overview of the findings of recent clinical trials on BsAbs, including mechanisms of action, safety profiles, and efficacy, and discuss the role of BsAbs in the treatment of B-cell lymphomas and multiple myeloma.

Impact of M-protein detection on the response evaluations of patients undergoing treatment with the IgG-κ monoclonal antibodies daratumumab or isatuximab, and discrepancies between immunofixation electrophoresis (IFE) systems and reagents.

BACKGROUND: Immunofixation electrophoresis (IFE) is the standard method for confirming the presence of a monoclonal protein (M-protein) at multiple myeloma (MM) diagnosis. IFE is also essential at assessment of complete response (CR) and stringent CR during treatment. As the CR assessment is influenced by daratumumab and isatuximab, HYDRASHIFT assays were developed. METHODS: Samples from patients under treatment that included daratumumab or isatuximab were tested and monitored by IFE on the HYDRASYS system using HYDRASHIFT assays (HYDRASYS/HYDRASHIFT) and by IFE on the Epalyzer2 system (Epalyzer). RESULTS: The IFE using HYDRASYS/HYDRASHIFT avoided a false positive caused by drug-related IgG-κ and contributed to accurate assessment of CR. Furthermore, HYDRASYS/HYDRASHIFT detected small M-proteins at early relapse and detected free light chains (FLCs) in patients with renal impairment exhibiting high serum FLCs despite being often missed on Epalyzer. CONCLUSION: Sensitivity and specificity of M-protein detection vary greatly depending on the IFE system and reagents used.

Complex karyotype determined using conventional cytogenetic analysis is a poor prognostic factor in patients with multiple myeloma.

High-risk cytogenetic abnormalities (HRCAs) influence the prognosis of multiple myeloma (MM). However, additional cytogenetic aberrations can lead to poor outcomes. This study aimed to clarify whether HRCAs and additional chromosomal abnormalities affect MM prognosis. Patients with newly diagnosed MM who were treated with novel agents were retrospectively evaluated. The primary objective was to assess the difference in progression-free survival (PFS) and overall survival (OS) between patients with/without HRCAs and between patients with/without complex karyotype (CK). The secondary objectives were to identify factors affecting PFS/OS and factors related to CK. HRCAs were defined as del(17p), t(4;14), t(14;16), and gain/amplification(1q) assessed using fluorescence in situ hybridization. CK was defined as ≥3 chromosomal abnormalities on G-banding. Among 110 patients, 40 had HRCAs and 15 had CK. In this study, survival durations between patients with/without HRCAs were similar, while the CK group had significantly poorer PFS/OS than the no-CK group (median PFS: 9 vs. 24 months and median OS: 29 vs. 97 months, respectively), and a poor prognostic impact of CK was maintained in patients with HRCAs. In multivariate analysis, CK was correlated with poor PFS/OS (hazard ratio [HR]: 2.39, 95% confidence interval [95% CI]: 1.22-4.66 and HR: 2.66, 95% CI: 1.10-6.45, respectively). Bone marrow plasma cell (BMPC) ≥60% (odds ratio [OR] = 6.40, 95% CI: 1.50-27.2) and Revised International Staging System III (OR = 7.53, 95% CI: 2.09-27.1) were associated with CK. Our study suggests that CK may contribute to the poor prognosis of MM. Aggressive disease status including high BMPC proliferation could be relevant to CK.

Prognostic value of post-treatment serum soluble interleukin-2 receptor in newly diagnosed diffuse large B-cell lymphoma patients who achieved complete metabolic response following R-CHOP therapy.

Patients with DLBCL achieving complete metabolic response (CMR) after initial treatment with R-CHOP generally have a favourable prognosis; however, there are no established prognostic biomarkers for relapse in these patients. Soluble interleukin-2 receptor (sIL-2R) levels at diagnosis are prognostic factors in patients with DLBCL. However, the significance of post-treatment sIL-2R levels is unclear. To determine the significance of post-treatment serum sIL-2R levels on subsequent relapse and survival, we retrospectively analysed 485 patients with newly diagnosed DLBCL who received R-CHOP treatment and achieved CMR. The cumulative incidence of relapse (CIR) was significantly higher in patients with elevated post-treatment sIL-2R levels than in those with normal sIL-2R levels (five-year CIR; 38.8% vs. 12.8%). The prognostic value remained significant in multivariable analysis (hazard ratio, 2.30; p < 0.001). Five-year progression-free survival (49.0% vs. 83.5%) and overall survival (61.7% vs. 91.6%) rates were lower in patients with elevated post-treatment sIL-2R levels than in those with normal sIL-2R levels (p < 0.001 for both). In patients with newly diagnosed DLBCL who achieved CMR after R-CHOP treatment, the post-treatment serum sIL-2R level was an independent prognostic marker of subsequent relapse and survival.

Serum cell-free DNA concentration as a possible prognostic marker in newly diagnosed diffuse large B-cell lymphoma.

Cell-free DNA (cfDNA) is a fragment of DNA circulating in the blood, and its concentration is often elevated in cancer patients. To investigate the relationships between serum cfDNA concentration and clinical characteristics, including prognosis, we measured serum cfDNA concentration in 114 newly diagnosed lymphoma patients. The cfDNA concentrations in diffuse large B cell lymphoma (DLBCL) (62.5 ng/mL) and follicular lymphoma patients (51.6 ng/mL) were significantly elevated compared to healthy individuals (7.5 ng/mL, P < 0.001). In DLBCL, patients with elevated serum cfDNA (> 38.9 ng/mL) at diagnosis had significantly shorter time-to-progression compared to those without (P = 0.033). The addition of cfDNA concentration to the international prognostic index showed improved predictive power for time-to-progression. Moreover, cfDNA added significant prognostic value to other inflammatory markers such as B symptoms and sIL2R. There was a trend towards shorter progression-free survival and overall survival in patients with elevated cfDNA. Furthermore, B symptoms (P = 0.038), bulky masses (P = 0.031), non-GCB subtype (P = 0.012), and serum sIL-2R levels > 2,000 U/mL (P = 0.012) were associated with higher cfDNA levels. Our study showed that serum cfDNA concentration at diagnosis was associated with certain clinicopathological characteristics, and may be predictive of survival outcomes in DLBCL patients.

Rituximab maintenance improves outcomes of transformed diffuse large B-cell lymphoma: a retrospective study of 519 cases with de novo diffuse large B-cell lymphoma and 62 cases with concurrent diffuse large B-cell lymphoma and follicular lymphoma.

Although outcomes of transformed diffuse large B-cell lymphoma (DLBCL) from follicular lymphoma (FL) were improved using rituximab-combined immunochemotherapy, the efficacy of subsequent rituximab maintenance (RM) remains unclear. We retrospectively analyzed the prognoses of 519 patients with de novo DLBCL and 62 patients with concurrent DLBCL and FL (concurrent-DLBCL/FL). Progression-free survival (PFS) was shorter in patients with concurrent-DLBCL/FL than in de novo DLBCL (p=.030). Twenty-four patients with concurrent-DLBCL/FL received RM after induction therapy, and they achieved better OS and PFS (p=.010 and p<.001, respectively) with lower risk of relapse (p<.001) than the non-RM group. Moreover, concurrent-DLBCL/FL showed better subsequent OS and PFS after recurrence than de novo DLBCL (p=.0083 and p=.0044, respectively). Our study indicates that in the face of a high relapse rate, concurrent-DLBCL/FL is manageable and benefits from RM.

The clonal evolution during long-term clinical course of multiple myeloma.

Somatic gene mutations related to acceleration disease and clonal evolution in multiple myeloma strongly influence severe clinical outcomes. In this study, we traced the transition of somatic mutations during the clinical course of myeloma patients over a long-term follow-up period (8.5 year average). Seven myeloma cases treated with immuno-chemotherapy at our institution were analyzed with clinical courses and the results of FISH and G-band analyses. Furthermore, the target sequences in regard to 121 genes, related to driver mutations or acceleration of disease in myeloma, were performed using bone marrow myeloma samples by next-generation sequencing, Ion Proton™ System. We detected a relationship between an increase in the dominant mutated gene (e.g., TP53, DIS3, FAM46C, KDM6B, and EGR1) and poor prognosis. In particular, clonal escalation of the TP53 mutation could not be overcome by any treatment. The selection of a combination treatment conducted in conjunction with the monitoring of gene mutations is appropriate for long-term survival. Our data demonstrate that long-term follow-up of somatic gene mutations during the clinical course of myeloma is helpful in the development of an effective treatment strategy.

Progression-free survival at 24 months as a predictor of survival outcomes after CHOP treatment in patients with peripheral T-cell lymphoma: a single-center validation study in a Japanese population.

Peripheral T-cell lymphoma (PTCL) is a group of aggressive lymphomas commonly treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Progression-free survival at 24 months (PFS24) constitutes a survival predictor for some lymphomas but has not been examined in Asian populations. We retrospectively investigated whether PFS24 was predictive of survival outcomes after CHOP treatment in 73 Japanese patients with PTCL. Patients without PFS24 had shorter median subsequent overall survival (OS) (20.2 vs. 121.0 months, p < 0.001) and shorter median subsequent progression-free survival (5.0 vs. 17.1 months, p = 0.03). Patients without PFS24 had worse overall (62.5% vs. 100%) and complete response rates (45.8% vs. 96.0%) (both p < 0.001). PFS24 absence (hazard ratio: 3.34, p = 0.004) and poor performance status (hazard ratio: 3.17, p = 0.04) were independently predictive of shorter OS. These findings suggest that PFS24 is predictive of survival after CHOP treatment in Japanese patients with PTCL.

Insignificance of surveillance imaging in patients with diffuse large B-cell lymphoma who achieved first complete remission: a retrospective cohort study.

The aim of this study was to evaluate the value of scheduled imaging for patients who achieved first complete remission after CHOP-like chemotherapy plus rituximab. In this retrospective cohort study, we included 759 patients newly diagnosed with de novo diffuse large B-cell lymphoma (DLBCL) at the Cancer Institute, Japanese Foundation for Cancer Research. Relapsed patients were divided into two groups based on method of diagnosis: clinical symptoms (symptom group, n = 57) or scheduled imaging (imaging group, n = 27). Our primary goal was to compare overall survival and relapse-free survival between the two groups. No significant difference in outcomes was found between the symptom and imaging groups. Median overall survival [7.5 years; 95% confidence interval (CI) 4.0-9.7 vs. 9.1 years; 95% CI 2.7 to not reached; P = 0.747), and median relapse-free survival (1.8 years; 95% CI 1.4-2.5 vs. 2.4 years; 95% CI 1.2-4.4; P = 0.108). Surveillance imaging in patients with DLBCL who achieved first complete remission did not demonstrate an advantage in terms of overall survival or relapse-free survival.