A new generation of cancer therapies is rapidly transforming oncology as bispecific antibodies move from scientific promise to clinical reality. Reported by Nature, researchers are now developing increasingly sophisticated multispecific antibodies capable of targeting multiple biological pathways simultaneously, with the aim of making treatments more effective, less toxic and better equipped to overcome tumour resistance.
The landscape of cancer treatment is undergoing a significant transformation as bispecific antibodies emerge as one of the most promising advances in modern oncology. According to reporting by Nature, these engineered molecules, designed to bind two separate biological targets simultaneously, are rapidly moving from laboratory research into clinical practice, while scientists are already pushing beyond them to create even more sophisticated multispecific antibodies capable of recognising three or more targets at once.
The pace of development has accelerated dramatically in recent years. Christian Klein, who previously developed antibody-based medicines at the pharmaceutical company Roche in Basel, Switzerland, and is now establishing his own biotechnology firm, says that the number of bispecific antibodies approved by regulators worldwide has increased from just three to more than twenty over the past five years. Reflecting their growing clinical and commercial importance, these medicines generated US$18 billion in sales during 2025.
Researchers view this expansion as evidence that the technology has reached a turning point. “Bispecifics have really kind of exploded,” Paul Carter, who develops antibody therapies at Genentech in South San Francisco, California, told Nature. Describing the remarkable diversity of these medicines, he remarked that “there are more flavours of bispecifics than Ben and Jerry’s ice cream.”
The success of these therapies, together with advances in protein production techniques and artificial intelligence, is now encouraging scientists to pursue even more ambitious approaches. Daniel Chen, co-founder and chief executive of Synthetic Design Lab in San Carlos, California, says researchers are increasingly focusing on multispecific antibodies capable of interacting with three or more biological targets simultaneously. At the American Association for Cancer Research Drug Discovery and Development meeting held in Boston, Massachusetts, at the end of July, scientists presented several multispecific antibody therapies designed to reduce damage to healthy tissue, improve the destruction of tumours and better counter cancer’s ability to evolve resistance to treatment.
Although bispecific antibodies have attracted widespread attention only recently, the concept itself is not new. The molecules were first described more than half a century ago, yet the first therapeutic application was not approved until 2009. According to Jamie Spangler, a bioengineer at Johns Hopkins University in Baltimore, Maryland, much of that delay resulted from the technical difficulty of manufacturing these highly complex proteins.
Early attempts often produced unstable molecules that failed to function as intended. Rather than binding to their intended targets, many antibodies attached to themselves or one another, creating unusable protein aggregates. “They would all come out as aggregated balls of garbage,” Spangler told Nature. Improvements in protein production technologies have fundamentally changed those prospects. “With better tools and resources for protein production, we can dream up these molecules and make them happen,” she said.
Many of the bispecific antibodies currently approved for clinical use function as so-called T-cell engagers. These medicines simultaneously bind proteins found on cancer cells and proteins present on immune cells known as T cells. By physically bringing the two cells together, the antibodies stimulate the immune system to recognise and attack cancerous tissue more effectively. At least twelve T-cell engager therapies have already received approval for treating cancers including leukaemia and myeloma.
Despite these achievements, researchers believe substantial improvements remain possible. Carter says a deeper understanding of tumour biology and immune-cell behaviour is enabling scientists to design antibodies that stimulate stronger anti-cancer immune responses while incorporating mechanisms that prevent treatment from becoming active until it reaches the appropriate location within the body.
Chen argues that these advances reflect a broader shift in scientific understanding. “We’re getting to this point where we’re starting to understand biology at a completely different level,” he told Nature. For multispecific antibodies, he says, success depends upon understanding biological complexity sufficiently well to engineer molecules capable of exploiting it.
Reducing toxicity remains one of the field’s central objectives. At the Boston meeting, Djuro Karanovic of AstraZeneca, based in Cambridge, United Kingdom, presented the company’s trispecific T-cell engagers. These molecules are designed to target a specific class of T cells capable of attacking tumours, thereby reducing the likelihood of triggering harmful immune reactions caused by activating a wider range of immune cells.
Scientists are also exploring methods that allow multispecific antibodies to distinguish more accurately between malignant and healthy tissue. One strategy involves designing antibodies that recognise additional cancer-associated proteins, thereby reducing the probability that healthy cells will be unintentionally targeted during treatment.
At the same time, the field is expanding beyond T-cell engagers altogether. Several major pharmaceutical companies are developing bispecific antibodies capable of simultaneously blocking PD-1, a protein that suppresses immune responses against cancer, and VEGF, a protein involved in blood-vessel formation that can also weaken immune activity. Although clinicians already administer separate antibodies against these proteins for certain cancers, combining both actions within a single bispecific antibody could produce a more powerful therapeutic effect.
One such medicine has already entered clinical practice. China has approved ivonescimab, developed by Akeso in Zhongshan, China, for treating certain forms of lung cancer. Its approval represents a significant milestone for this therapeutic strategy and demonstrates how bispecific antibodies are moving beyond experimental development into patient care.
Even so, researchers caution that the growing focus on PD-1 and VEGF should not limit scientific ambition. Spangler acknowledges that targeting both proteins has become a validated therapeutic approach, making it understandable that numerous companies are pursuing similar medicines. Nevertheless, she believes genuine progress depends on continued innovation rather than concentrating research efforts on a single pathway.
“Sure, you can make a better mousetrap, but at the end of the day, the innovation is what’s really exciting,” Spangler told Nature. “That means finding new targets, new formats, and new ways to use antibodies to their maximum capacity.”
As reported by Nature, the rapid expansion of bispecific antibodies illustrates how advances in molecular engineering, protein science and biological understanding are reshaping cancer research. While the latest generation of therapies has already established a growing clinical presence, researchers are now looking beyond dual-target approaches towards increasingly sophisticated multispecific medicines that could offer more precise, more effective and potentially safer treatments for cancer patients in the years ahead.
