HM15912 A Novel LongActing GLP2 Analog

Why a New GLP2 Analog?

Native GLP2 has a short plasma halflife (~7min) due to rapid degradation by dipeptidyl peptidase4 (DPP4) and renal clearance. Existing therapeutics (e.g., teduglutide) require daily injections, which limits patient adherence and convenience. The goal of HM15912 is to retain the full biological activity of GLP2 while dramatically extending exposure.

Key Molecular Features

• Fattyacid acylation at the Cterminus provides reversible albumin binding, slowing renal filtration.
• Proteaseresistant aminoacid substitutions at positions 2 and 13 protect against DPP4 and neutral endopeptidase cleavage.
• Optimized receptorbinding domain preserves high affinity for the GLP2 receptor (GLP2R) with EC₅₀ 0.3nM, comparable to native peptide.
• PEGlinker (5kDa) improves solubility and further reduces immunogenicity.

The combined modifications generate a molecule with an apparent halflife of 57days in humans, enabling onceweekly dosing.

Pharmacodynamics

Intestinal Effects

HM15912 stimulates proliferation of crypt enterocytes, increases villus height and expands the mucosal surface area. In preclinical models, treatment resulted in:

• 3040% increase in jejunal villus height.
• Up to 50% increase in nutrient absorption capacity (fat, protein, carbohydrate).
• Reduced intestinal permeability measured by FITCdextran assay.

Systemic Effects

Although GLP2 actions are largely gutrestricted, HM15912 modestly raises plasma levels of IGF1 and reduces inflammatory cytokines (TNF, IL6), suggesting secondary benefits in mucosal healing and immune modulation.

Therapeutic Indications Under Investigation

HM15912 is being evaluated in three primary disease areas:

1. Short Bowel Syndrome (SBS) Patients with extensive intestinal resections rely on parenteral nutrition. By enhancing absorptive capacity, HM15912 aims to reduce dependency on intravenous support.
2. Inflammatory Bowel Disease (IBD) In Crohns disease and ulcerative colitis, mucosal barrier dysfunction contributes to relapse. GLP2 analogue therapy may promote remission and mucosal healing.
3. Radiotherapyinduced enteropathy Radiation damages the epithelium; GLP2 analogues have shown protective effects in animal models.

Preclinical Data

Animal studies in rats and nonhuman primates demonstrated:

• Steadystate plasma concentrations after weekly dosing for 8weeks.
• No accumulation beyond predicted levels; clearance consistent with albuminbinding kinetics.
• No observable toxicological signals at 10fold the projected clinical exposure.
• Significant improvement in body weight gain and stool output in SBS models.

Clinical Development

Phase1 (Healthy Volunteers)

Singleascending and multipleascending dose studies showed:

• Linear pharmacokinetics between 0.1mg and 1mg weekly.
• Mean halflife of 5.8days, supporting weekly administration.
• Most common adverse events: mild injectionsite erythema and transient nausea.
• No antibody formation detected after 12weeks.

Phase2 (SBS Cohort)

In a doubleblind, placebocontrolled trial (n=84), patients receiving 0.5mg HM15912 weekly for 24weeks achieved:

• Mean reduction of 40% in parenteral nutrition volume.
• Increase in serum citrulline (a marker of enterocyte mass) by 25%.
• Improved qualityoflife scores (SF36 physical component 8 points).

Safety profile remained comparable to placebo, with no serious drugrelated events.

Ongoing Studies

Two Phase2b trials are enrolling:

• HM15912IBD01 (moderatetosevere Crohns disease, n=120).
• HM15912RAD02 (patients undergoing pelvic radiotherapy, n=90).

Phase3 pivotal SBS study is planned for 2027.

Safety & Tolerability

Across all studies, HM15912 has shown a favorable safety profile. The most frequently reported events are mild and transient:

• Injectionsite reactions (redness, itching).
• Gastrointestinal discomfort (nausea, mild abdominal cramping).
• Headache.

No clinically significant changes in laboratory parameters (including liver enzymes, renal function, and hormonal panels) have been observed.

Administration & Dosing

HM15912 is supplied as a sterile, prefilled 1mL syringe containing 0.5mg of peptide in aqueous buffer (pH7.4). Recommended dosing for SBS is 0.5mg subcutaneously once weekly, administered at the same day each week. Dosing for other indications will be determined based on ongoing trial outcomes.

Future Directions

Beyond the current therapeutic areas, research is exploring:

• Combination therapy with GLP1 analogues for synergistic effects on intestinal adaptation.
• Oral delivery platforms using permeation enhancers to further simplify administration.
• Biomarker development to identify patients who will benefit most (e.g., baseline citrulline levels, GLP2R expression).

The longacting nature of HM15912 also opens possibilities for chronic disease management where daily injections are impractical.

Key Takeaways

1. HM15912 is a chemically engineered GLP2 analogue with a halflife of 6days, enabling onceweekly dosing.
2. It retains full GLP2 receptor potency while being resistant to enzymatic degradation.
3. Preclinical and early clinical data demonstrate robust intestinotrophic activity and a clean safety profile.
4. Phase2 results in short bowel syndrome show significant reductions in parenteral nutrition need and improved patientreported outcomes.
5. Ongoing trials will clarify its role in IBD, radiation enteropathy, and potentially other mucosal disorders.