Serenatus Bio is developing a novel COMT inhibitor based on Tolcapone, an old drug that showed efficacy in OCD but had severe liver toxicity. This strategy uses a flawed predecessor's clinical signal as proof-of-concept, de-risking the biological hypothesis while focusing innovation on solving the safety issues.

Serenatus Bio develops three distinct drug programs for OCD, acknowledging that no single treatment is universally effective in heterogeneous psychiatric conditions. This multi-asset approach diversifies risk and increases the probability of successfully treating different patient subpopulations.

In the difficult CNS space, novel drugs often fail because of an inability to prove target engagement in humans. By choosing metabolic targets, Leal can use clear biomarkers from blood tests or imaging to de-risk its programs and provide early proof of efficacy to investors, clinicians, and partners.

For CNS diseases, where animal models are notoriously unreliable predictors of efficacy, the most pragmatic R&D model is to quickly move promising new chemical entities into human trials. The focus shifts from extensive preclinical validation to early biological experimentation in humans for proof-of-concept.

The extensive translational and biomarker work published in Nature from a Phase 1 study of Casdatifan is a model for modern drug development. Understanding the drug's mechanism, pharmacodynamics, and response signatures from day one provides a 'backup plan' and helps avoid costly Phase 3 failures.

Derek Small argues the breakthrough in neuroscience mirrors oncology's shift from blunt instruments to targeted therapies. By focusing on underlying pathology like synaptic dysfunction and neuroinflammation, rather than just symptoms, developers can achieve biomarker-based approvals and more effective treatments.

Multiple effective OCD treatments—neurosurgery, deep brain stimulation, and TMS—all directly or indirectly target the anterior cingulate cortex. This convergence of different modalities provides strong biological validation for new drugs that also modulate this specific brain region.

Unusually for a Phase 1 safety trial, Gain Therapeutics measured lipid levels in patients' cerebrospinal fluid. They observed a decrease in the target toxic lipids, providing strong, early biological evidence that the drug reaches the brain and works as intended. This de-risks future development by establishing a clear biomarker of effect.

Instead of targeting complex downstream glutamate receptors, Leal Therapeutics inhibits a single upstream enzyme, glutaminase. This mechanistically simpler approach avoids the off-target effects of receptor-based drugs and allows for direct, quantifiable measurement of target engagement, a major advantage in CNS trials.