Chagas disease, spread by the so-called “kissing bug,” affects 6–7 million people worldwide. Left untreated, it can cause heart failure and even death.

There are drugs for it—benznidazole and nifurtimox—but here’s the problem:

– They’re old.

– They’re harsh.

– And they don’t work well enough for every patient.

This is where you, the founder or innovator, should lean in.

 The Founder Lesson

Repurposed or neglected drugs can be turned into real breakthroughs. They save years of R&D, tap into decades of data, and meet urgent medical needs.

 But here’s the truth: repurposing only works if toxicology guides the strategy.

Think of toxicology as your guardrail. Without it, you risk a crash—regulatory rejection, trial failure, or patient harm.

 Why Toxicology Still Matters

Changing the “what for” changes the risk. For Chagas and drugs like it:

– New patients: Safe in adults ≠ safe in children or pregnant women.

– Longer use: Taking a drug daily for months is a different risk than a 2-week course.

– Side effects: Old drugs may cause liver or nerve problems that were overlooked before.

– New formulations: A pill reformulated for kids (say, liquid suspension) needs fresh safety checks.

The Toxicology Advantage (Founder Playbook)

If you’re building in this space, here’s how toxicology becomes your accelerator—not your bottleneck:

 Start with what’s known – Decades of safety data exist. Mine it like gold.

 Spot the gaps – Ask: “Does this still hold true for kids, seniors, or long-term use?”

 Stress-test scenarios – Use models to predict liver, nerve, or heart risks before trials.

 Design smarter trials – Toxicology tells you what regulators will ask and what doctors should monitor.

 Engage FDA early – FDA guidance is clear: if you change how a drug is used (new dose, route, or population), you must revisit safety. Don’t wait for them to tell you—show them you’ve done it.

 Why Investors Should Care

For investors, toxicology isn’t overhead—it’s risk insurance.

– It prevents late-stage blowups.

– It signals funding readiness.

– It turns a “nice idea” into a durable asset.

 The Takeaway

Chagas isn’t just a neglected disease.
It’s a case study in how old drugs can unlock new opportunities.

Repurposing is the shortcut.
Toxicology is the guardrail.
Together, they make you unstoppable.

 References

– World Health Organization. Chagas disease (American trypanosomiasis): https://www.who.int/health-topics/chagas-disease

– FDA. Nonclinical Safety Evaluation of Reformulated Drug Products and Products Intended for Administration by an Alternate Route: https://www.fda.gov/media/119657/download

– FDA. M3(R2) Nonclinical Safety Studies for the Conduct of Human Clinical Trials and Marketing Authorization: https://www.fda.gov/media/71542/download

– FDA. Predictive Toxicology Roadmap: https://www.fda.gov/science-research/advancing-alternative-methods-fda/implementing-alternative-methods

– Bern C. Chagas’ Disease. N Engl J Med. 2015;373:456–466: https://www.nejm.org/doi/full/10.1056/NEJMra1410150