The Next Frontier In Drug Discovery: Reinventing Old Platforms To Solve New Problems

By Jeff Fischer, MBA, cofounder and president, Longhorn Vaccines and Diagnostics

As the current administration looks to accelerate drug development and reduce healthcare costs, one of its emerging strategies is repurposing and finding new uses for old drugs. The logic for this approach is sound because it’s supported by decades of safety data that make these compounds faster to deploy and easier to approve.

But there’s a parallel — and perhaps even more powerful — opportunity: rather than revisiting old drugs, why not repurpose entire platforms with proven safety profiles?

Today’s biopharmaceutical toolkit includes well-understood modalities like monoclonal antibodies (mAbs), whose clinical behavior, manufacturing, and safety data are among the most thoroughly characterized in medicine. The data is so strong that in September 2025, the FDA announced it will waive clinical efficacy studies for monoclonal antibody biosimilars. By combining these trusted technologies with new biological targets, we can create therapies that retain known safety while addressing emerging or previously intractable diseases.

Platform Innovation Vs. Molecule Repurposing

Traditional drug repurposing — using existing small molecules for new indications — has been a valuable but limited approach. Many older drugs are blunt instruments, developed before the molecular underpinnings of disease were well understood, including many of the platform technologies that have accelerated drug development in the last five years.

In contrast to traditional drug repurposing, platform innovation uses established therapeutic frameworks — peptides, viral vectors, or mAbs — and adapts them to novel targets. The result is new therapies with predictable pharmacology and minimal safety compromise.

This approach retains the regulatory and manufacturing advantages of repurposing, while restoring innovation to the biology itself.

Why Monoclonal Antibodies Lead The Way

No platform better illustrates this principle than mAbs. Since the first approval in 1986, antibodies have evolved from experimental biologics into one of the safest and most versatile therapeutic classes in medicine because their specificity minimizes off-target toxicity, their long half-life allows infrequent dosing and stable blood levels, and predictable immunogenicity and well-defined manufacturing processes have de-risked development timelines.

mAbs are one of the fastest growing classes of therapeutics, having gained momentum with the recent increase of drug-resistant viruses, as well as its use in oncology with solid tumors and as an immunotherapy for breast, cervical, and gastric cancers.

These features and diverse applications make mAbs uniquely suited for rapid adaptation to new targets — whether infectious agents, inflammatory triggers, or metabolic regulators. With over 100 approvals and thousands of candidate molecules characterized, the safety and performance of the antibody scaffold are extraordinarily well understood.

Extending The Reach: Half-Life Extended Antibodies

Recent advances have made antibodies even more durable. Fc engineering and neonatal Fc receptor (FcRn) optimization now enable half-lives measured not in days but in months.

Extended half-life antibodies mean fewer injections, greater patient adherence, and sustained disease suppression, which is ideal for chronic conditions or preventive use. For developers, these molecules offer both commercial and clinical leverage: one well-tuned antibody can replace an entire class of shorter-acting biologics.

This concept is already transforming infectious disease prevention. Extended half-life antibodies like nirsevimab have proved that a single dose can protect infants from respiratory syncytial virus (RSV) for an entire season. The same logic applies far beyond virology, including chronic inflammatory and age-related diseases driven by persistent immune activation.

Case Study: Targeting Peptidoglycan — A Universal Trigger Of Inflammation

At Longhorn Vaccines and Diagnostics, we’re applying this platform-first strategy to a new frontier: the neutralization of bacterial cell wall components that drive systemic inflammation and disease.

Our extended half-life monoclonal antibody, MD11, targets peptidoglycan (PGN) — a conserved structural molecule found in all bacteria. Research shows that PGN leaks into circulation through the epithelial (gut, skin, and gums) barriers as people age, continuously activating the immune system and fueling chronic inflammation, which is the foundation of cardiovascular disease, diabetes, Alzheimer’s, and autoimmune disorders.

By combining a proven antibody platform with a novel universal inflammatory target, we maintain the safety and pharmacokinetic advantages of mAbs while addressing an entirely new category of disease drivers.

In preclinical work, MD11 demonstrates:

• cross-reactivity to Gram-positive, Gram-negative bacterial PGN, and Mycobacterial PGN as well as the Stem peptide AEKA
• strong binding to Gram-positive, Gram-negative, and Mycobacteria at mid-log stage growth
• potent opsonophagocytic and neutralizing activity against live bacteria.

This fusion of familiar scaffolds with new biology represents the next step in rational innovation — one that rewards both scientific rigor and translational efficiency.

A Blueprint For Safer, Faster Innovation

The policy momentum toward “safe innovation” doesn’t have to stop at repurposing small molecules. Instead, regulators and developers can expand their focus to modular platforms with well-documented safety and manufacturing consistency.

When these platforms are matched with validated but underexploited biological targets, the path to clinical and commercial success becomes shorter, safer, and more predictable. In the case of extended half-life mAbs, that means faster regulatory review grounded in decades of safety data; streamlined chemistry, manufacturing, and controls (CMC) and analytical pathways; predictable pharmacology across targets and indication; and accelerated translation of novel discoveries into viable therapeutics.

The Future Belongs To Proven Platforms

As the life sciences industry balances the urgency of innovation with the need for safety and cost control, the most transformative advances may come not from rediscovering old drugs but from reimagining trusted technologies.

Platforms like extended half-life mAbs embody the best of both worlds with the security of known safety and the excitement of new biological frontiers.

At companies like Longhorn, we see mAbs not as an isolated molecule but as part of a broader movement to leverage proven platforms to address the molecular root of disease. There are even companies offering the infrastructure to improve workflows for drug developers that may not have access to in-house technology. By building on what’s already safe and effective, we can accelerate discovery, reduce risk, and deliver next-generation solutions that the world can trust.

About The Author

Jeff Fischer, MBA, president of Longhorn Vaccines and Diagnostics, is responsible for the oversight of all non-scientific aspects of the organization, including regulatory affairs. Fischer cofounded the company and served as its chief financial officer from 2007 to 2017. From 1998 to 2005, Fischer served as an executive vice president and CFO in the biotechnology industry. He is a former infantry officer in the United States Marine Corps and holds an MBA from the University of Texas at Austin.