The bispecific antibody Ivanesimab binds to the VEGF dimer, creating a "daisy chain" of antibody-VEGF complexes. This multimerization concentrates the drug in the tumor microenvironment, where VEGF is high, and enhances its ability to bind and block PD-1 more effectively than single-molecule approaches.

Unlike checkpoint inhibitors, the bispecific antibody Pazridamig (targeting HK2 and CD3) shows promising early signals in heavily pretreated prostate cancer. It demonstrated a low rate of side effects and convenient dosing, suggesting a viable new immunotherapeutic pathway.

Previously underperforming cancer targets like TIGIT and LAG-3 are seeing renewed interest. Innovative antibody engineering, such as creating bispecific antibodies that target multiple pathways simultaneously, is giving these 'failed' targets new life and potential for clinical success.

The initial hope for a revolution across many immune checkpoints has faded. With most targets outside of PD-1 failing to deliver, investors and pharma have grown fatigued. This disappointment has accelerated the industry's pivot towards other modalities like ADCs and cell therapies.

A therapeutic approach called "T-cell engagers" or "BiTEs" uses engineered antibodies with two different heads. One side binds to a cancer cell, while the other binds to a nearby T-cell. This effectively brings the killer cell and the target together, leveraging the body's existing immune cells without genetic modification.

An innovative strategy for solid tumors involves using bispecific T-cell engagers to target the tumor stroma—the protective fibrotic tissue surrounding the tumor. This novel approach aims to first eliminate this physical barrier, making the cancer cells themselves more vulnerable to subsequent immune attack.

Beyond simply blocking the PD-1/PD-L1 pathway, these bispecifics may form a macromolecular structure with VEGF and PD-L1 in the tumor microenvironment. This structure can cause the cancer cell to internalize the PD-L1 protein, effectively removing it as a target and creating a dual blockade.

Unlike bevacizumab's long 20-day half-life and associated bleeding risks that excluded squamous cell carcinoma patients, new bispecifics have a ~6-day half-life. This results in a similar but less severe toxicity profile, broadening their clinical application to a wider patient population.

The bispecific antibody Pumitamig demonstrated identical overall response rates in both PD-L1 positive and negative triple-negative breast cancer patients. This is significant as it provides a potential immunotherapy option for the two-thirds of patients who are PD-L1 negative and currently ineligible for such treatments.