Sironax to Present Obesity Drug Data at ObesityWeek
The clinical-stage biotech will show two SIR4156 abstracts in poster sessions at the Obesity Society's annual meeting in November.
Updated on Nov. 4, 2026 in Weight Loss
Sironax, a clinical-stage biotechnology company headquartered in Waltham, Massachusetts, will present two abstracts on its NAMPT activator SIR4156 at ObesityWeek 2026 on November 14. The company also advanced enrollment in its Phase 2 FORGE-LM obesity trial of the compound.
Why it matters
SIR4156 is being developed as a potential standalone or combination therapy for obesity that aims to reduce metabolically harmful fat while preserving lean muscle mass. The drug has not been approved by the FDA or any other regulator, and its safety and efficacy in humans have not yet been established.
The announcement rests on two abstracts, one reporting preclinical weight-lowering effects in diet-induced obese mice and one a carcinogenicity risk assessment, with no human efficacy figures disclosed. Whether these animal findings will translate to patients remains unknown, and the Phase 2 FORGE-LM results have not been reported.
The players
Sironax
A global clinical-stage biotechnology company based in Waltham, Massachusetts, named to Fierce Biotech's 2026 Fierce 15 list, and developer of the NAMPT activator SIR4156.
Obesity Society
The professional society whose annual ObesityWeek meeting serves as a major forum for obesity and metabolic research presentations.
The details
Sironax's SIR4156 is an orally active, first-in-class allosteric NAMPT activator designed to restore NAD+ homeostasis and boost cellular energy metabolism. In multiple preclinical models, the company reports preferential fat loss, lean-mass preservation, reduced muscle atrophy and improved physical performance.
Timeline
November 14, 2026: Both SIR4156 abstracts are scheduled for poster sessions from 7:30 to 8:30 p.m. ET in Exhibit Hall BCD.
November 14-17, 2026: The ObesityWeek 2026 meeting of the Obesity Society takes place at the Gaylord National Resort & Convention Center in National Harbor, Maryland.
Big Picture
SIR4156 targets NAMPT, the rate-limiting enzyme in the NAD+ salvage pathway, extending NAD+-focused metabolic research from aging and mitochondrial studies into obesity drug development. Whether an allosteric activator of this enzyme can deliver fat loss without the carcinogenicity concerns raised in one of its abstracts is the central question for the program.
SIR4156 is not available to patients and has no approved use, so current weight-loss options are unchanged. Any eventual treatment would depend on Phase 2 FORGE-LM results and regulatory review, which have not yet occurred.
The takeaway
Preclinical animal data showing fat loss and muscle preservation is an early signal, and the clinical picture for SIR4156 will depend on human trial results. Readers should treat the poster presentations as preliminary, not as evidence of an available treatment.
What happens next
Sironax is scheduled to present both SIR4156 abstracts in poster sessions at ObesityWeek 2026 on November 14, 2026.
Further reading
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