Drug development continues to advance at a remarkable speed, yet the underlying paradox of the field remains unchanged. Each new therapeutic program requires extraordinary investment in time, capital, expertise, and technological infrastructure. Despite this, a large fraction of drug candidates that once appeared scientifically sound ultimately fail during clinical development, most often due to toxicity, insufficient delivery, or marginal efficacy. Many of these molecules quietly disappear, even though their original biological rationale remains valid.
From a scientific perspective, this represents not only loss but inefficiency. If a subset of these shelved molecules could be revisited, redesigned, and re-evaluated using modern delivery and targeting strategies, the potential savings in both time and resources would be substantial. Yet in practice, such efforts face a structural barrier: without perceived “novelty,” second attempts struggle to attract investment, regardless of their scientific merit.
A Conceptual Breakthrough: Beyond Single-Modality Thinking
A recent study by Xiang Yu et al. provides an instructive example of how this impasse might be addressed. The authors reported an antibody–siRNA–Exatecan conjugate (AREC), a construct that is notable not merely for its composition, but for the conceptual framework it represents.
Exatecan, a potent topoisomerase I inhibitor, has long been constrained by hydrophobicity and systemic toxicity. Antibody–siRNA conjugates (ARCs), while mechanistically attractive, remain underexplored in oncology applications. By integrating siRNA with a highly potent small-molecule payload, the study demonstrated two important advances: mitigation of DAR-associated toxicity and the emergence of genuine pharmacological synergy. In this case, STAT3 gene silencing was coupled with Exatecan-mediated cytotoxicity, resulting in enhanced antitumor activity beyond what either modality could achieve alone.
This work highlights a critical point: conjugation should not be viewed solely as a delivery solution. Rather, it can serve as a framework for coordinating multiple mechanisms of action within a single therapeutic entity.
Pushing the Idea Further: Two Parallel Architectures
The AREC concept naturally raises a broader question. Can the next generation of therapeutics move beyond single-modality optimisation toward deliberately engineered, multi-component architectures?
Two parallel strategies merit particular attention:
• Antibody + Drug + Third Party
• Antibody + siRNA/ASO + Third Party
In both cases, the inclusion of a third functional component introduces a new degree of freedom, mechanistically, pharmacokinetically, and biologically. This additional layer enables modulation of efficacy, toxicity, or resistance pathways in ways that conventional ADC or AOC designs cannot easily achieve.
Why Multi-Component Designs Matter
The implications of such architectures extend beyond incremental improvement. Multi-component designs offer a plausible route to resurrecting previously abandoned oncology assets by improving therapeutic index, refining exposure profiles, or enabling cell-type–specific activity. They may also substantially enhance the clinical potential of siRNA or ASO modalities, particularly in solid tumors where delivery and durability remain persistent challenges.
Importantly, this concept is not restricted to the AREC framework. It can be generalised across existing ADC and AOC platforms, where a third functional partner, whether a molecular modulator, stabiliser, or biological amplifier, can introduce new mechanisms or rebalance efficacy and safety.
There is a growing consensus that traditional chemotherapeutics, broadly cytotoxic agents with limited selectivity, will gradually recede from the forefront of oncology. ADCs and AOCs have already reshaped expectations around targeted delivery and therapeutic precision. The next evolutionary step may well involve multi-component conjugates that intentionally integrate distinct modalities to achieve more durable and controllable responses.
Our Perspective at Glycogene
At Glycogene, Prof. Peng Wang and colleagues are actively pursuing this direction. We have established an independent Antibody + Drug + Third-Party platform designed to be compatible with a wide range of payload classes. Early preclinical data are encouraging, demonstrating more than a 20% improvement over DS-8201, enhanced tumor suppression in mouse models, and, in selected cases, complete tumor regression.
While this platform remains under active development, its underlying mechanism and generalizability suggest potential applicability across many existing ADC payloads—including compounds previously regarded as suboptimal or unsuccessful. From a scientific standpoint, this reinforces the idea that therapeutic value is not fixed at the level of the payload alone, but can be reshaped through architecture and system-level design.
Conclusion
Both Antibody + Drug + Third Party and Antibody + siRNA/ASO + Third Party strategies represent credible and intellectually compelling paths forward. They challenge conventional assumptions about novelty, failure, and modality boundaries, and they offer a framework for redesigning not merely replacing- therapeutic molecules. If pursued rigorously, such approaches may redefine how the field rescues, reinvents, and advances drug candidates in the coming decade. The future of therapeutics is likely to be broader, more integrated, and more modular than we have previously imagined.
