Abaloparatide
A PTHrP-analog anabolic for bone with one of the cleanest phase-3 datasets in this entire catalog — in postmenopausal osteoporosis. In anyone with open growth plates, the literature contains nothing at all.
The short version
- ACTIVE (n=2,463, 18 months, double-blind): vertebral fractures 0.57% vs 4.77% placebo — one of the larger relative reductions in osteoporosis trials. DATA
- Head-to-head with teriparatide in the same trial (open-label arm): numerically fewer vertebral and clinical fractures, similar nonvertebral. DATA
- Hip-region BMD gains of +7.25 to +9.73% in meta-analysis — where teriparatide historically struggles. DATA
- Zero studies in pediatric or open-plate populations exist; the label excludes open epiphyses. DATA (an absence, verified by search)
ACTIVE — the trial
| Arm | n | Vertebral fx | Nonvertebral fx | Clinical fx |
|---|---|---|---|---|
| Placebo (blinded) | 821 | 4.77% | 3.0% | 4.3% |
| Abaloparatide 80 µg/d (blinded) | 824 | 0.72% | 3.0% | 4.0% |
| Teriparatide 20 µg/d (open) | 818 | 0.99% | 5.3% | 9.0% |
What meta-analysis adds
Hip BMD: +7.25–9.73% DATA
Pooled hip-region BMD gains across abaloparatide studies (Sheth 2025 meta-analysis) — notable because the older anabolic, teriparatide, historically shows flat-to-small early hip responses. Fracture-outcome meta-analyses put vertebral RR at 0.13–0.21 vs placebo (Bonifacio 2026).
vs teriparatide: small OR advantages, overlapping confidence DATA
Network meta-analysis (Beaudart 2025): nonvertebral fracture OR 0.87, hip fracture OR 0.81 for abaloparatide vs teriparatide — direction favors abaloparatide, intervals overlap. In men specifically (Lu 2026 network MA, n=4,409): lumbar-spine BMD +7.31 (CI 4.25–10.37) — but male fracture endpoints remain limited.
Why it exists — mechanism in one paragraph
A selective PTH1-receptor agonist tuned for “anabolic window” signaling DATA
34-amino-acid analog of PTHrP. It biases toward the Gs/cAMP (anabolic, transient) arm of the PTH1 receptor relative to the β-arrestin arm engaged harder by teriparatide — the proposed reason for its slightly better BMD-per-hypercalcemia profile. Same class logic as PTH: intermittent dosing builds bone; continuous exposure resorbs it. That asymmetry is dose-schedule-dependent, not optional.
What does not exist — the whole story for young users
No pediatric study · no open-plates study · no young-athlete study DATA
Verified by systematic search (2026-08-28): there is no study of abaloparatide in children, adolescents, or any population with open growth plates — no trial, no case series, no case report. The FDA label excludes open epiphyses, carrying the rat osteosarcoma signal inherited from the PTH class (teriparatide's black box originated in exactly that rat study; abaloparatide's carcinogenicity program showed the same dose-dependent rat findings). What the drug does to an actively fusing human plate — accelerate, distort, or nothing — is not in the literature.
And the mechanistic prior runs through the same plate GH spends MODEL
Premise: PTH-analog anabolism acts on osteoblast-lineage cells, and the growth plate's chondrocyte columns and their bony remodeling are osteoblast-mediated. Premise: in adult bone the drug is net-anabolic only intermittently dosed. Logic: in an open plate there is no data to say which way the net effect lands, and the label's exclusion exists precisely because that experiment was never done. Prediction: unquantifiable — anyone claiming a height or plate effect for this drug in the young is inventing it.