Kinases
33 articles
Kinase Inhibitor Reshapes Its Own Binding Pocket to Gain Selectivity
- Researchers led by Seidler and colleagues designed a small-molecule inhibitor of p38δ (p38 delta), a MAP kinase linked to cancer, and reported its binding mechanism in Angewandte Chemie International Edition.
- Structural analysis showed the inhibitor initially collided with a flexible loop lining the kinase's ATP-binding pocket, a clash that would normally be expected to weaken or block binding.
- Instead of being excluded, the inhibitor caused that loop to change conformation and fold around the molecule, producing an unusually tight, self-encapsulating fit within the remodeled pocket.
- The authors present this induced-fit, pocket-remodeling behavior as a previously undescribed route to kinase selectivity, distinct from conventional structure-based design, which treats the binding pocket as a fixed template the inhibitor must be shaped to match.
- The finding suggests that deliberately exploiting pocket flexibility, rather than avoiding steric clashes, could become a strategy for engineering selectivity in future kinase-targeted drug design.
The steric clash was the feature, not the bug — that's the part that makes me sit up. We're trained to treat the ATP pocket as a fixed template and design ligands to fit it; here the loop folded around the inhibitor and the "bad" collision became the selectivity handle. That inverts the whole lock-and-key mental model. Selectivity-wise, this is a genuinely new lever. Everyone's chasing hinge tweaks, DFG-out, or allosteric pockets — induced self-encapsulation is a different axis entirely, and worth stealing for other kinase programs. My skepticism: is this designable, or did they get lucky in one series and rationalize it after the crystal structure came back? Rational pocket-remodeling on demand would be huge; a one-off induced-fit anecdote is just a nice paper. Also worth noting: p38δ is far less drugged than p38α, so any new selectivity trick here has real headroom.
Alumis' Lupus Trial Misses Goals Overall, but High-Interferon Subgroup Responds
- Alumis' Phase 2b LUMUS trial of envudeucitinib, an oral TYK2 inhibitor, missed its primary and key secondary endpoints in the overall lupus (SLE) patient population.
- A prespecified subgroup with a high interferon gene signature (IFNGS-high) — the patient profile most reliant on the Type I interferon pathway that TYK2 inhibition targets — showed a clear, placebo-separated response on the same endpoints.
- These IFNGS-high patients were underrepresented in the overall study population, which diluted the topline result.
- The drug was well tolerated, with no new safety signals.
- Alumis plans to redesign its Phase 3 program around IFNGS-high patients, engage the FDA before year-end, and separately still intends to file for U.S. psoriasis approval by the end of 2026.
A miss with an asterisk, not a pivot. IFNGS-high response is biologically coherent — interferon signature is literally TYK2's mechanism — so this isn't pure spin like some post-hoc subgroup rescues. But shrinking Phase 3 to biomarker-enriched patients trades a bigger addressable market for a better shot at significance; that's the right call scientifically, wrong one commercially unless a companion diagnostic scales cleanly. Versus BMS's already-approved Sotyktu, Alumis needed a clean topline to differentiate TYK2 in autoimmune beyond psoriasis — it didn't get one. Expect the Street to stay skeptical until FDA blesses the enrichment strategy; a >50% drop doesn't reverse on a CEO's confidence alone. Psoriasis filing is now doing the heavy lifting for the story — good, since it's biomarker-agnostic — but lupus was supposed to be the platform proof point, and that thesis just got smaller.
Alumis' TYK2 drug fails in lupus trial; CEO sees 'clear path forward' ↗
Novartis's Remibrutinib Succeeds in Phase III Multiple Sclerosis Trials
- Novartis reported positive topline Phase III results from the REMODEL-1 and REMODEL-2 trials of remibrutinib in relapsing multiple sclerosis, with the drug outperforming active comparator teriflunomide.
- Remibrutinib, an oral BTK inhibitor, reduced annualized relapse rate and inflammatory brain lesions versus teriflunomide across both identically designed studies.
- The trials also showed a positive trend toward slowing disability progression, with a meaningful signal in a preplanned combined analysis.
- Safety data were reassuring, showing no liver safety signal, consistent with remibrutinib's existing profile in chronic spontaneous urticaria.
- Novartis plans to present late-breaking data at an upcoming MS conference and pursue global regulatory submissions for this indication.
Beating teriflunomide isn't the same as beating the field's real benchmark — ocrelizumab, natalizumab, the high-efficacy therapies most MS neurologists already reach for first. Still, the safety data are the real story here. Hepatotoxicity has dogged this drug class, including flags on Sanofi's rival tolebrutinib program, so a clean liver readout is a genuine differentiator, not just noise. If remibrutinib's selectivity truly spares the liver, Novartis gets real separation in the BTK race rather than a me-too label. Add this to the existing CSU approval and Novartis is building an actual platform molecule — one asset, multiple indications, shared manufacturing and commercial muscle. The number to watch next: whether that disability-progression trend holds up, since that's what actually shifts prescribing.