This 2011 Lancet narrative review by Rachner, Khosla, and Hofbauer maps the molecular biology of osteoblast-osteoclast communication to explain how novel therapeutic targets were identified. It covers three antiresorptive mechanisms (RANKL inhibition, cathepsin K inhibition, Src kinase inhibition) and two anabolic strategies (sclerostin antibody, Dkk-1 antibody), with clinical trial data available at the time of publication.
Denosumab works fundamentally differently from bisphosphonates — it targets a circulating cytokine (RANKL) rather than incorporating into bone mineral, which means its effects are fully reversible.
That reversibility is a double-edged sword. When you stop denosumab, RANKL signaling resumes rapidly and overshoots baseline, driving a rebound surge in bone turnover within 6 months. In practice: never discontinue denosumab without a transition plan to a bisphosphonate or other antiresorptive.
Denosumab also has a meaningful advantage in renal impairment. It requires no dose adjustment (unlike bisphosphonates, which are contraindicated when creatinine clearance falls below 30–35 mL/min). Though hypocalcemia risk rises with severe renal dysfunction.
The odanacatib and sclerostin data in this review established that not all antiresorptives are equivalent at the cellular level. Agents that preserve osteoclast viability (uncoupled antiresorptives) maintain the osteoclast-to-osteoblast paracrine signal, theoretically reducing the over-suppression of bone formation seen with bisphosphonates and denosumab. Whether this translates to fewer atypical femur fractures or osteonecrosis of the jaw remains an open question, but it frames why romosozumab (anti-sclerostin) entered clinical use as a bone-building rather than purely antiresorptive agent.
This 2011 Lancet narrative review by Rachner, Khosla, and Hofbauer maps the molecular biology of osteoblast-osteoclast communication to explain how novel therapeutic targets were identified. It covers three antiresorptive mechanisms (RANKL inhibition, cathepsin K inhibition, Src kinase inhibition) and two anabolic strategies (sclerostin antibody, Dkk-1 antibody), with clinical trial data available at the time of publication.
Denosumab works fundamentally differently from bisphosphonates — it targets a circulating cytokine (RANKL) rather than incorporating into bone mineral, which means its effects are fully reversible.
That reversibility is a double-edged sword. When you stop denosumab, RANKL signaling resumes rapidly and overshoots baseline, driving a rebound surge in bone turnover within 6 months. In practice: never discontinue denosumab without a transition plan to a bisphosphonate or other antiresorptive.
Denosumab also has a meaningful advantage in renal impairment. It requires no dose adjustment (unlike bisphosphonates, which are contraindicated when creatinine clearance falls below 30–35 mL/min). Though hypocalcemia risk rises with severe renal dysfunction.
The odanacatib and sclerostin data in this review established that not all antiresorptives are equivalent at the cellular level. Agents that preserve osteoclast viability (uncoupled antiresorptives) maintain the osteoclast-to-osteoblast paracrine signal, theoretically reducing the over-suppression of bone formation seen with bisphosphonates and denosumab. Whether this translates to fewer atypical femur fractures or osteonecrosis of the jaw remains an open question, but it frames why romosozumab (anti-sclerostin) entered clinical use as a bone-building rather than purely antiresorptive agent.