Bispecific antibodies (bsAbs) are molecules that simultaneously bind two different antigens (Ags). bsAbs represent a very active field in tumor immunotherapy with more than one hundred molecules currently being tested. More specifically, they have elicited a great interest in the setting of non-Hodgkin’s lymphoma (NHLs), where they could represent a viable option for more fragile patients or those resistant to other conventional therapies. This review aims to give a brief overview of the different available bsAb formats and their mechanisms of action, pinpointing the differences between IgG-like and non-IgG-like classes and will then focus on those in advanced clinical development for NHLs.

We are currently witnessing a dramatic shift in our approach to the treatment of B-cell non-Hodgkin lymphoma (B-NHL). In the evolving clinical landscape, novel treatments for this clinically heterogeneous disease span a wide range of interventions, encompassing targeted agents, cell therapy approaches, and novel monoclonal antibodies (NMABs). Among these, the latter are likely to exert the most profound impact due to their distinctive high efficacy and versatile applicability. NMABs represent a heterogeneous group of agents, including naked antibodies, immunotoxins, and T-cell-engaging molecules. In recent times, several NMABs have either gained regulatory approval or are on the verge of introduction into clinical practice, addressing multiple therapeutic indications and treatment regimens. Their anticipated impact is expected to be broad, initially in the context of relapsed/refractory (R/R) disease and subsequently extending to early treatment lines. The scope of this review is to provide a comprehensive overview of the biological characteristics, clinical properties, efficacy, and toxicity profiles of NMABs that have recently been introduced or are nearing integration into clinical practice.

To define the role of spleen stiffness (SS) and liver stiffness (LS) in myelofibrosis and other Philadelphia (Ph)-negative myeloproliferative neoplasms (MPNs), we studied, by ultrasonography (US) and elastography (ES), 70 consecutive patients with myelofibrosis (MF) (no.43), essential thrombocythemia (ET) (no.10), and polycythemia vera (PV) (no.17). Overall, the median SS was not different between patients with MF and PV (p = 0.9); however, both MF and PV groups had significantly higher SS than the ET group (p = 0.011 and p = 0.035, respectively) and healthy controls (p < 0.0001 and p = 0.002, respectively). In patients with MF, SS values above 40 kPa were significantly associated with worse progression-free survival (PFS) (p = 0.012; HR = 3.2). SS also correlated with the extension of bone marrow fibrosis (BMF) (p < 0.0001). SS was higher in advanced fibrotic stages MF-2, MF-3 (W.H.O. criteria) than in pre-fibrotic/early fibrotic stages (MF-0, MF-1) (p < 0.0001) and PFS was significantly different in the two cohorts, with values of 63% and 85%, respectively (p = 0.038; HR = 2.61). LS significantly differed between the patient cohort with MF and healthy controls (p = 0.001), but not between the patient cohorts with ET and PV and healthy controls (p = 0.999 and p = 0.101, respectively). We can conclude that organ stiffness adds valuable information to the clinical work-up of MPNs and could be employed to define patients at a higher risk of progression.

Optimal consolidation for young patients with relapsed/refractory (R/R) follicular lymphoma (FL) remains uncertain in the rituximab era, with an unclear benefit of autologous stem cell transplantation (ASCT). The multicenter, randomized, phase 3 FLAZ12 (NCT01827605) trial compared anti-CD20 radioimmunotherapy (RIT) to ASCT as consolidation after chemoimmunotherapy, both followed by rituximab maintenance (RM). Patients (age 18-65 years) with R/R FL and without significant comorbidities were enrolled and treated with three courses of conventional, investigator-chosen chemoimmunotherapies. Those experiencing at least a partial response were randomized 1:1 to ASCT or RIT before CD34+ collection, and all received post-consolidation RM. Progression-free survival (PFS) was the primary endpoint. The target sample size was 210 (105/group). During Aug 2012-Sept 2019, of 164 screened patients, 159 were enrolled (median age 57 [49-62] years, 55% male, 57% stage IV, 20% bulky disease). The study was closed prematurely because of low accrual. Data were analyzed on June 8, 2023, on an intention-to-treat basis, with a 77-month median follow-up from enrollment. Of 141 patients (89%), 70 were randomized to ASCT and 71 to RIT. Estimated 3-yrs PFS in both groups was 62% (HR 1.11, 95% CI 0.69-1.80, P = 0.6662). Three-year overall survival also was similar between the two groups. Rates of grade ≥3 hematological toxicity were 94% with ASCT vs 46% with RIT (P < 0.001), and grade ≥3 neutropenia occurred in 94% vs 41%, respectively (P < 0.001). Second cancers occurred in nine patients after ASCT and three after radioimmunotherapy (P = 0.189). Even if prematurely discontinued, our study did not demonstrate superiority of ASCT vs RIT. ASCT was more toxic and demanding for patients and health service. Both strategies yielded similar, favorable long-term outcomes, suggesting that consolidation programs milder than ASCT require further investigation in R/R FL.

Mantle cell lymphoma (MCL) is a biologically and clinically heterogeneous B-cell malignancy with a historically poor prognosis. Recent advances have substantially expanded treatment options, particularly through the integration of targeted therapies, chemotherapy-free regimens, and cellular approaches. Frontline treatment now incorporates Bruton’s tyrosine kinase inhibitors (BTKi) in combination with chemotherapy and in chemotherapy-free regimens. For patients with relapsed or refractory disease, particularly those previously exposed to BTKi, chimeric antigen receptor T-cell (CAR T) therapies and third-generation BTKi like pirtobrutinib provide highly effective options while several novel agents, including bispecific antibodies (bsAbs), are under investigation. Nevertheless, achieving long-lasting remissions is still a major challenge, especially among high-risk patients. Future directions include optimizing sequencing, refining rational combination therapies, expanding the application of bsAbs, and integrating small molecules and novel immunoconjugates to enhance therapeutic efficacy and long-term outcomes. This review provides an overview of the current and emerging therapies for MCL, highlighting how the integration of biological agents, strategic combinations, and patient-centered approaches are driving the next phase of MCL treatment.