Dosage research on AOD-9604

Preclinical research dose ranges

In published preclinical research on AOD-9604 and the parent hGH(176-191) lipolytic fragment, administered dose ranges in rodent studies have most commonly fallen in the 0.05 to 1 milligram per kilogram range delivered subcutaneously or intraperitoneally. The Heffernan and colleagues line of work characterised the lipolytic and anti-lipogenic profile across this dose range in genetic-obesity (ob/ob) and diet-induced-obesity murine models across multi-week protocols.

In-vitro lipolysis studies on adipocyte and adipose-tissue-explant cultures have most commonly used AOD-9604 at micromolar concentrations in the culture medium. Effects on basal and stimulated lipolysis, on lipogenic-enzyme expression, and on adipocyte differentiation markers have been reported across this concentration range. The acute pharmacokinetic literature reports a short circulating half-life, with functional effects persisting beyond what the half-life alone would predict.

The protein-engineering rationale for AOD-9604 was to retain the lipolytic activity of the hGH(176-191) fragment while eliminating the growth-promoting effects of intact growth hormone. Preclinical work has characterised this dissociation profile across the dose ranges described above, with the published research reporting lipolytic effects without measurable IGF-I elevation in matched rodent protocols.

Clinical trial dose ranges

The published clinical-trial literature on AOD-9604 has tested specific dose levels in obesity contexts. Phase 2 trials have tested 1 mg subcutaneously daily over multi-month observation windows in adults with obesity. Earlier dose-ranging work tested 0.25 mg, 0.5 mg, and 1 mg daily across shorter observation windows. These doses are reported here as published clinical-trial doses, not as recommendations.

AOD-9604 is not approved by the FDA or Health Canada as a human therapeutic. The Phase 2 clinical-trial data did not advance the compound to Phase 3, and AOD-9604 remains in research-grade rather than approved-therapeutic status.

Dose-response considerations from the published literature

The published AOD-9604 Phase 2 clinical-trial literature has reported dose-response characteristics across the 0.25 mg to 1 mg daily subcutaneous range in adults with obesity. Body-weight effects scaled with dose across the tested range, with the 1 mg daily dose providing the upper-end clinical exposure characterised in the published trials. Preclinical dose-response work has shown lipolytic effects scaling with dose across the 0.05 to 1 milligram per kilogram rodent range.

The cross-species dose-translation depends on the pharmacokinetic differences between rodent and human and on the endpoint being measured. The published clinical-trial data did not advance to Phase 3, and any extension of the dose-response curve beyond the Phase 2 tested range remains untested in the indexed clinical literature.

Reconstitution math and per-vial dose calculation

A 5 mg lyophilised AOD-9604 vial reconstituted with 1 mL of bacteriostatic water yields a stock concentration of 5 mg per mL. From this stock, a research aliquot of 0.1 mL contains 500 micrograms; an aliquot of 0.2 mL contains 1 milligram (matching the Phase 2 daily clinical dose if dosing on a per-vial basis is desired for comparator-arm research replication). Researchers working with rodent pharmacology dose ranges further dilute the stock to a working concentration appropriate to the model and the body weight of the animal subject. Refrigerated storage at 2 to 8 degrees Celsius, protected from light, is the standard handling practice.

Research-protocol design considerations

Protocol-design choices in the published AOD-9604 literature reflect several recurring considerations. Phase 2 clinical-trial dose selection anchors at the 0.25 mg / 0.5 mg / 1 mg daily subcutaneous range. Preclinical dose selection anchors at the 0.05 to 1 milligram per kilogram range subcutaneously in rodent models.

Route of administration in both clinical and preclinical work is overwhelmingly subcutaneous. Daily dosing in clinical work reflects the short circulating half-life. Rodent protocols use comparable daily-to-twice-daily dosing cadences across multi-week observation windows for body-weight and lipolytic endpoints.

The hGH(176-191) origin with N-terminal tyrosine modification is a protocol-design consideration in any comparison with intact growth hormone or with other growth-hormone-related research compounds. AOD-9604 retains the lipolytic activity of the hGH C-terminal fragment without producing measurable IGF-I elevation; protocol designs interested in distinguishing lipolytic from growth-promoting effects of GH-axis manipulation use this dissociation in comparator-arm experimental design.

References

1. Heffernan M et al. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice. Endocrinology, 2001. [PMID 11250895]
2. Ng FM et al. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Hormone Research, 2000. [PMID 10895024]
3. Heffernan MA et al. Increase of fat oxidation and weight loss in obese mice caused by chronic treatment with human growth hormone or a modified C-terminal fragment. International Journal of Obesity, 2001. [PMID 11571589]