Osteoprotegerin (OPG)
Evidence: B/C — Meaningful Human EvidenceEndocrine / Calcium-Bone Axis Signaling
Evidence Snapshot
What this grade covers
B applies to native OPG's genetic evidence (two independent primary papers). C applies to any claim implying AMG/AMGN-0007's engineered-construct outcomes are literally unmodified native OPG's own outcomes — AMG/AMGN-0007 is an Fc-fusion, not exact-sequence native OPG, and its evidence is PRODUCT_SPECIFIC_EVIDENCE (plus HISTORICAL_PROGRAM_CONTEXT for the 2003 study), never DIRECT_NATIVE_HUMAN_INTERVENTION or RECOMBINANT_PRODUCT_EXACT_SEQUENCE relative to native OPG. This is an explicit scope exclusion, not an oversight.
Regulatory Context
Native OPG is an endogenous secreted decoy receptor with no approved product of its own. A recombinant OPG-Fc fusion construct ('AMG 0007'/'AMGN-0007') was studied in two human clinical contexts in the early-to-mid 2000s but never reached approval; it is a distinct engineered molecule, not native OPG. The available evidence base does not establish why this construct's development did not proceed to approval; no specific cause should be stated.
Research Takeaway
Osteoprotegerin (OPG, TNFRSF11B gene product) is a native, secreted soluble decoy receptor that binds RANKL and prevents it from activating RANK, thereby restraining osteoclast-mediated bone resorption.
See all 3 evidence claims →Quick Summary
Osteoprotegerin (OPG) is the body's own natural 'off switch' for RANKL, and by extension for bone resorption. An early-2000s engineered OPG-Fc fusion construct was tested in a small number of patients but never approved — that construct is not native OPG, and current approved therapy in this pathway (denosumab) targets RANKL directly rather than using OPG.
Mechanism & Research Overview
Osteoprotegerin (OPG) is the body's own natural 'off switch' for RANKL, and by extension for bone resorption. An early-2000s engineered OPG-Fc fusion construct was tested in a small number of patients but never approved — that construct is not native OPG, and current approved therapy in this pathway (denosumab) targets RANKL directly rather than using OPG.
Evidence Claims
Individual scientific statements drawn from the sources cited below, each shown with the specific evidence boundary that statement does not establish.
Supported
Osteoprotegerin (OPG, TNFRSF11B gene product) is a native, secreted soluble decoy receptor that binds RANKL and prevents it from activating RANK, thereby restraining osteoclast-mediated bone resorption.
Sources: Osteoprotegerin deficiency and juvenile Paget's disease
Supported
Loss-of-function TNFRSF11B mutations, independently reported in more than one case/family, cause juvenile Paget's disease (idiopathic hyperphosphatasia), a rare autosomal-recessive disorder of markedly accelerated bone turnover, directly demonstrating OPG's necessity for normal restraint of bone resorption in humans.
Sources: Osteoprotegerin deficiency and juvenile Paget's disease; A mutation in the gene TNFRSF11B encoding osteoprotegerin causes an idiopathic hyperphosphatasia phenotype
Supported
A recombinant OPG-Fc fusion construct ('AMG 0007'/'AMGN-0007') — an engineered molecule combining an OPG-derived domain with an antibody Fc region, not unmodified native OPG — was studied in two distinct human clinical contexts: a Phase I dose-escalation study in cancer patients with lytic bone metastases, where it suppressed a urinary bone-resorption marker; and a compassionate-use study in two adult siblings with juvenile Paget's disease, where it produced bone-mass increases and reduced bone turnover over 15 months.
Does not establish
Evidence boundary: Neither study's specific findings may be described as direct evidence about native, unmodified circulating OPG. The available evidence base does not establish why this construct's development did not proceed to approval; no specific cause (such as antibody formation) should be asserted without independent primary support.
Sources: A phase I study of AMGN-0007, a recombinant osteoprotegerin construct, in patients with multiple myeloma or breast carcinoma related bone metastases; Recombinant osteoprotegerin for juvenile Paget's disease
Safety & Evidence Limitations
Considerations reported in the sources cited on this page — not a complete list of every possible risk, and not medical advice.
Higher-Priority Safety Consideration
The only human intervention evidence in this family used an engineered OPG-Fc fusion construct, not unmodified native OPG; specific efficacy/safety numbers must not be attributed to native circulating OPG. This is this batch's single highest-priority claim-writing hazard.Safety Consideration
No primary source establishes why the AMG 0007 development programme did not proceed to approval; any future claim must not assert a specific cause.Safety Consideration
Juvenile Paget's disease is extremely rare; the genetic evidence base, while clean, rests on a small number of reported cases/families.
Research Areas Being Studied
Research areas discussed on this page reflect the Endocrine / Calcium-Bone Axis Signaling category and the sources cited below.
Findings Reported in Studies
Educational summary only — reported in cited studies, not a claim of proven benefit.
- Recombinant osteoprotegerin for juvenile Paget's disease (2005):
- A phase I study of AMGN-0007, a recombinant osteoprotegerin construct, in patients with multiple myeloma or breast carcinoma related bone metastases (2003):
- A mutation in the gene TNFRSF11B encoding osteoprotegerin causes an idiopathic hyperphosphatasia phenotype (2002):
- Osteoprotegerin deficiency and juvenile Paget's disease (2002):
Study Tables by Evidence Type
Human Studies & Clinical Data
| Title | Year | Population / Model | Dose / Duration / Finding | Safety Notes | Source |
|---|---|---|---|---|---|
| Recombinant osteoprotegerin for juvenile Paget's disease | 2005 | CRITICAL FIREWALL SOURCE. The recombinant osteoprotegerin construct studied here, 'AMG 0007', is an IgG1-Fc-fused engineered molecule, NOT unmodified native circulating OPG. Administered subcutaneously once weekly (0.3-0.4 mg/kg) to 2 adult siblings with juvenile Paget's disease over 15 months: radial bone mass increased 9% and 30% in the two patients respectively, skeletal bisphosphonate retention decreased 37% and 55%, with radiographic improvement. Classification: PRODUCT_SPECIFIC_EVIDENCE (engineered OPG-Fc fusion construct), NOT DIRECT_NATIVE_HUMAN_INTERVENTION and NOT RECOMBINANT_PRODUCT_EXACT_SEQUENCE relative to native OPG. Same construct lineage as study-opg-body-2003-pmid12548591 (AMGN-0007), a distinct clinical application (oncology bone-metastasis context) of the same molecule. The available evidence base does NOT establish why this construct's development did not proceed to approval; no specific cause (e.g., antibody formation) should ever be asserted. | |||
| A phase I study of AMGN-0007, a recombinant osteoprotegerin construct, in patients with multiple myeloma or breast carcinoma related bone metastases | 2003 | CRITICAL FIREWALL SOURCE. AMGN-0007, the same engineered recombinant OPG-Fc fusion construct lineage as study-opg-cundy-2005-pmid16135836, studied in a randomized, double-blind, dose-escalation Phase I trial: N=28 multiple myeloma and N=26 breast-carcinoma patients with lytic bone lesions. A single SC dose produced rapid, sustained suppression of urinary NTX/creatinine (bone-resorption marker); 4 serious adverse events reported (3 breast-carcinoma, 1 myeloma). Classification: PRODUCT_SPECIFIC_EVIDENCE plus HISTORICAL_PROGRAM_CONTEXT (this oncology programme did not proceed to approval) — NOT DIRECT_NATIVE_HUMAN_INTERVENTION, NOT native unmodified OPG evidence. Cause of non-approval is not established by any available source; do not assert one. | |||
| A mutation in the gene TNFRSF11B encoding osteoprotegerin causes an idiopathic hyperphosphatasia phenotype | 2002 | Independent primary genetic identity paper: a TNFRSF11B mutation causes idiopathic hyperphosphatasia (juvenile Paget's disease), a second, independently-reported confirmation of OPG's necessity for normal bone-resorption restraint in humans. | |||
| Osteoprotegerin deficiency and juvenile Paget's disease | 2002 | Osteoprotegerin (OPG, TNFRSF11B gene product) deficiency causes juvenile Paget's disease, a rare autosomal-recessive disorder of markedly accelerated bone turnover — direct human genetic evidence establishing OPG's normal role restraining osteoclast-mediated bone resorption. |
Animal / Cell / Preclinical Data
No Animal / Cell / Preclinical Data Listed Yet
This section will be updated as sources are added.
Regulatory Documents & Official Trial Registries
No Regulatory Documents & Official Trial Registries Listed Yet
This section will be updated as sources are added.
Anecdotal Reported Patterns — Not Medical Advice
Anecdotal Reported Patterns — Not Medical Advice
Reported dosing patterns are included for educational context only. They are self-reported, unverified, not medical advice, and not instructions for human use. Community-submitted patterns are not yet available in this Phase 1 prototype; this section is a placeholder reserved for moderated, aggregated community data.
Lab Markers to Discuss With a Clinician
Educational topics only — not self-monitoring instructions.
FAQ
Disclaimer
Educational information only. This page summarizes published research and official regulatory information about Osteoprotegerin and does not provide medical advice, an individualized treatment recommendation, or dosing instructions.
Educational use only. This content is provided for informational and research-summary purposes only. It is not medical advice, not a treatment recommendation, not a dosing guide, and not a substitute for care from a licensed medical professional. Nothing here is intended to diagnose, treat, cure, prevent, or mitigate disease. Reported dosing patterns, when shown elsewhere on the site, must be labeled either as Study / Trial Dosing or Anecdotal Reported Patterns — Not Medical Advice. Community reports are self-reported, unverified, and not scientific proof.
Community-reported experiences, once enabled, must be displayed only as moderated, anonymized, or aggregated data. They are anecdotal, self-reported, unverified, and should never be presented as proof of safety, efficacy, or expected results.
Content status: Published. Last updated .
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