Bispecific Antibodies in Oncology (2020–2026): Clinical Advances, Target Biology, Safety, and the Commercial Landscape — A Narrative Review for Medical Professionals

Introduction

Bispecific antibodies (BsAbs)—engineered immunoglobulins designed to simultaneously engage two distinct antigens—have fundamentally reshaped oncology therapeutics over the past six years. Unlike conventional monoclonal antibodies, BsAbs leverage dual-targeting mechanisms to redirect cytotoxic T cells toward tumor cells, co-block immunosuppressive pathways, or combine angiogenic and immune-modulatory activity within a single molecule. Between 2020 and 2026, regulatory approvals have accelerated across three jurisdictions (FDA, EMA, and NMPA), pivotal trial evidence has matured, and an expansive late-stage pipeline has emerged across both hematologic malignancies and solid tumors. This review synthesizes clinical, safety, and commercial evidence for medical professionals including oncologists, hematologists, clinical researchers, and medical affairs teams. Key acronyms are defined on first use: overall response rate (ORR), complete response (CR), progression-free survival (PFS), overall survival (OS), duration of response (DoR), cytokine release syndrome (CRS), and immune effector cell-associated neurotoxicity syndrome (ICANS). Cross-trial comparisons are descriptive rather than definitive, as patient populations, prior therapy burden, and endpoint maturity differ substantially across studies 12.

Target Biology and Mechanism Landscape

The oncology BsAb landscape is organized into three principal strategic classes 1:

Table 1: Major BsAb Target Classes, Representative Agents, and Disease Areas

CD3-engaging agents dominate the approved hematology space and require no prior T-cell sensitization, enabling rapid immune synapses. Non-CD3 BsAbs, including checkpoint/VEGF constructs, seek to concentrate dual activity in the tumor microenvironment (TME) 23.

Clinical Advances in Hematologic Malignancies

The most mature and commercially validated BsAb evidence from 2020–2026 originates from hematologic cancers, where the field has progressed from late-line monotherapy toward frontline combination therapy, fixed-duration regimens, and post-transplant maintenance strategies 2.

Blinatumomab (CD19×CD3) remains the benchmark in acute lymphoblastic leukemia (ALL). In newly diagnosed standard-risk pediatric B-ALL, adding two cycles of blinatumomab to chemotherapy improved three-year disease-free survival to 96.0% versus 87.9% (hazard ratio [HR] 0.39), with grade 3+ CRS in only 0.3% of patients. In adults with newly diagnosed BCR::ABL1-negative B-lineage ALL who were measurable residual disease (MRD)-negative, three-year OS improved to 85% versus 68% with consolidation chemotherapy alone 2.

Epcoritamab (CD20×CD3), administered subcutaneously with a step-up priming schedule, has generated high-impact data across multiple lymphoma settings. In first-line diffuse large B-cell lymphoma (DLBCL) combined with R-CHOP, ORR was 100% and CR rate 87%, with 24-month PFS of 74%; in elderly/frail patients receiving epcoritamab plus R-mini-CHOP, 12-month OS reached 96%. In relapsed/refractory (R/R) follicular lymphoma (FL) combined with R2, ORR was 96% and CR 87% at a 21-month PFS of 80%. The phase 3 EPCORE FL-1 trial reported a PFS HR of 0.21 (95% CI: 0.13–0.33; p<0.0001) versus R2 alone, with a median PFS not yet reached versus 11.2 months in the control arm, and ORR 89% versus 74%. FDA traditional approval was granted in November 2025; EMA conditional marketing authorization (CMA) was issued in September 2023 2489.

Odronextamab (CD20×CD3) showed ORR 80.5% and CR 74.2% in R/R FL, with median DoR of 26.0 months and median PFS of 23.0 months. In R/R marginal zone lymphoma (MZL), ORR and CR were both 79.3%, with a durable 36-month DoR of 72.4% 2.

In multiple myeloma (MM), BCMA×CD3 and GPRC5D×CD3 agents have produced landmark results. Elranatamab plus daratumumab/lenalidomide in transplant-ineligible newly diagnosed MM achieved confirmed ORR of 91.9%, with 81.1% reaching very good partial response (VGPR) or better, though grade 3/4 adverse events occurred in 94.6% and infections in 64.9% 2. Teclistamab in post-transplant maintenance achieved CR rates exceeding 90% and MRD negativity in 100% of evaluable patients, with grade 3/4 infections and hypogammaglobulinemia remaining prominent 25. Talquetamab (GPRC5D×CD3) achieved ORR 67–74% across weekly and biweekly dosing cohorts; biweekly dosing showed longer median DoR (17.5 months) and PFS (11.2 months). In prior T-cell redirection-exposed patients, ORR remained 63% 5. Linvoseltamab (BCMA×CD3) produced ORR 70.9%, CR or better 49.6%, and median DoR 29.4 months in heavily pretreated MM, with median OS of 31.4 months 2.

Clinical Advances in Solid Tumors

Solid-tumor BsAb success through 2026 is more selective but increasingly validated, particularly for CD3-engaging agents targeting tumor-associated antigens and for PD-1/VEGF constructs 12.

Tarlatamab (DLL3×CD3) has delivered the strongest solid-tumor T-cell engager signal in the reviewed dataset. In a randomized phase 3 trial in relapsed SCLC (small cell lung cancer), tarlatamab improved median OS to 13.6 months versus 8.3 months with chemotherapy (HR 0.60) and PFS to 4.2 versus 3.7 months (HR 0.71). Grade ≥3 treatment-related adverse events were 27% versus 62% for chemotherapy; CRS was predominantly grade 1–2, with grade 3 CRS in only 1%. FDA accelerated approval was granted in May 2024 based on DeLLphi-301 trial data demonstrating ORR 40% (95% CI: 31–51) and median DoR of 9.7 months across 99 patients 237.

Ivonescimab (PD-1×VEGF), a tetravalent first-in-class molecule, achieved superiority over pembrolizumab monotherapy in first-line PD-L1–positive advanced NSCLC in China (HARMONi-2 trial), improving median PFS to 11.14 months versus 5.82 months (HR 0.51), ORR 50.0% versus 38.5%. Ivonescimab was approved in China in May 2024. A U.S. FDA BLA for ivonescimab plus platinum-doublet chemotherapy in EGFR-mutated post-TKI NSCLC was accepted for filing in January 2026, with a PDUFA goal date of November 14, 2026. Positive phase 3 OS results from HARMONi-A (post-TKI EGFR-mutated NSCLC) and superiority over tislelizumab in squamous NSCLC (HARMONi-6) were also reported 26.

BNT327/PM8002 (PD-L1/VEGF-A) showed preliminary activity across multiple solid-tumor cohorts, including an ORR of 42.2% and median PFS of 8.3 months in cervical cancer 2.

Approved Oncology Bispecific Antibodies (as of July 2026)

Table 2: Approved Oncology Bispecific Antibodies

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Key Late-Stage Pipeline Assets

Table 3: Selected Key Late-Stage Pipeline Bispecific Antibodies

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Safety Considerations and Management

CRS is the most frequent toxicity across T-cell–engaging BsAbs, occurring in 40–80% of patients depending on agent, dose, and disease burden. ICANS is less common (0–11%) but potentially severe. Step-up dosing protocols—beginning with sub-therapeutic priming doses and escalating over one to three cycles—substantially reduce grade ≥3 CRS incidence. As a representative example, tarlatamab's recommended dosing begins with 1 mg IV on Cycle 1 Day 1, escalating to 10 mg on Day 8 and Day 15, then 10 mg every two weeks thereafter 348.

Table 4: Clinically Relevant Safety-Management Considerations

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A critical safety distinction within the dataset: BCMA-targeting programs carry the highest infection burden, with hypogammaglobulinemia reported in up to 87% of teclistamab-treated patients and 71–87% of talquetamab-treated patients, necessitating IVIG prophylaxis 5. BsAbs demonstrate lower ICANS rates (~1–3%) compared with CAR-T cell therapies (~10–20%), attributed to slower kinetics of T-cell expansion 11.

Commercial and Competitive Landscape

The commercial BsAb landscape is led by Genmab/AbbVie (epcoritamab), Janssen/J&J (teclistamab, talquetamab), Amgen (blinatumomab, tarlatamab), Regeneron (odronextamab, linvoseltamab), Pfizer (elranatamab), Roche (mosunetuzumab, glofitamab), and Akeso/Summit Therapeutics (ivonescimab). China-based innovators including Akeso, Qilu Pharmaceuticals, Hengrui, and BioNTech/Biotheus are generating a high density of late-stage immunomodulatory programs 1.

Versus CAR-T cell therapies: BsAbs offer off-the-shelf availability (no patient-specific manufacturing), faster deployment, subcutaneous administration for some agents, reversibility, and estimated lower cost per course (approximately USD 150,000–300,000 versus USD 375,000–475,000 for approved CAR-T products). The trade-off is potentially shorter response durability; CAR-T therapies may achieve deeper and more durable responses in some populations, and head-to-head trials remain limited 11. Versus antibody-drug conjugates (ADCs): BsAbs rely on T-cell–mediated cytotoxicity and are currently approved primarily in hematologic malignancies; ADCs dominate selected solid-tumor niches via cytotoxic payload delivery. The two classes are largely complementary, with emerging combination strategies in development 11.

Subcutaneous (SC) administration is an increasingly prominent differentiator in hematology (epcoritamab, talquetamab, teclistamab, elranatamab), supporting outpatient delivery and broadening access. Most solid-tumor programs remain IV-based 12.

Resistance Mechanisms and Future Outlook

Resistance to T-cell engagers (TCEs) has been classified into tumor-intrinsic and tumor-extrinsic pathways 11. Tumor-intrinsic mechanisms include antigen heterogeneity/loss (mutations, downregulation, alternative splicing), lineage switching, resistance to granzyme/perforin-mediated apoptosis, and PD-L1 upregulation. Tumor-extrinsic mechanisms include immunosuppressive TME elements (cancer-associated fibroblasts, myeloid-derived suppressor cells, regulatory T cells, TGF-β/IL-10), physical barriers in solid tumors (dense extracellular matrix, abnormal vasculature, hypoxia), and T-cell exhaustion (PD-1, TIM-3, TIGIT upregulation).

Mitigation strategies under investigation include multi-antigen or trispecific BsAb designs, combination with checkpoint inhibitors or epigenetic modulators (5-azacitidine, HDAC inhibitors), co-stimulation strategies (CD28, 4-1BB engagement), and TME-targeted approaches (myeloid reprogramming, regulatory T-cell depletion) 11.

Priority directions for 2026 and beyond, based on the retrieved evidence, include: earlier-line treatment positioning (first-line DLBCL combinations, post-transplant MM maintenance); expansion of CD3-engaging platforms into additional solid tumors beyond SCLC; SC formulation development; biomarker-driven patient selection using T-cell subset composition, antigen density, and cytokine profiling; and combination strategies to overcome T-cell exhaustion and antigen escape. In China, rapid NMPA approval of ivonescimab and cadonilimab signals accelerating domestic BsAb commercialization, with broader indication expansion anticipated 610.

Conclusion

From 2020 to 2026, bispecific antibodies have transitioned from innovative clinical concepts to a validated, commercially active therapeutic class. CD3-engaging agents have fundamentally changed treatment sequencing in ALL, DLBCL, FL, and MM, while tarlatamab has validated T-cell redirection in SCLC. Non-CD3 BsAbs—particularly PD-1/VEGF constructs—are establishing a distinct competitive space in solid tumors, led by ivonescimab. Safety management via step-up dosing, tocilizumab availability, and infection prophylaxis has substantially improved clinical feasibility. As the field matures, earlier-line positioning, combination strategies, subcutaneous delivery, and resistance-mechanism-informed patient selection will define the clinical and commercial trajectory of oncology BsAbs beyond 2026. Formal cross-trial comparative conclusions remain limited by differences in study design and patient populations, and additional evidence from registrational trials and real-world practice is required to fully characterize long-term outcomes 1234567891011.