What evaluation and follow‑up recommendations should be done after a patient has completed 12 months of romosozumab (Evenity) therapy?

After Completing 12 Months of Evenity (Romosozumab)

Immediately transition to an antiresorptive agent—either a bisphosphonate or denosumab—without any washout period, and monitor bone mineral density (BMD) at 12-24 months to ensure maintenance of gains. 1, 2

Sequential Therapy is Mandatory

The anabolic effect of romosozumab wanes after 12 monthly doses, making sequential antiresorptive therapy essential to prevent bone loss and maintain fracture risk reduction 2. Do not allow any gap between completing romosozumab and starting the next agent—there is no rationale for a "washout period" 3.

Choice of Sequential Agent

First-line options:

• Denosumab 60 mg subcutaneously every 6 months, OR
• Bisphosphonates:
  • Zoledronic acid 5 mg IV annually
  • Alendronate 70 mg weekly orally
  • Risedronate 35 mg weekly orally

Selection factors:

• Denosumab may provide superior sustained BMD gains in the second year of sequential therapy 4
• Bisphosphonates are appropriate for most patients and showed equivalent 12-month outcomes to denosumab in real-world data 4
• Consider renal function (avoid bisphosphonates if eGFR <35 mL/min), gastrointestinal tolerance, patient preference, and adherence patterns 5, 6

Both denosumab and bisphosphonates effectively maintained BMD gains and showed similar fracture rates (6.3% each) in real-world follow-up, while patients without sequential therapy experienced BMD decline (-5.4% lumbar spine) and higher fracture rates (15.4%) 4.

Monitoring Protocol

Bone Mineral Density Assessment

• Timing: Obtain DXA scan at 12 months after starting sequential therapy, then again at 24 months 1
• Sites: Measure lumbar spine, total hip, and femoral neck 1
• Use the same facility and DXA machine when possible to ensure accurate comparison 1
• Expected outcomes: BMD gains from romosozumab should be maintained; further increases may occur with denosumab 2, 7

Bone Turnover Markers (Optional but Helpful)

• C-telopeptide (CTX) or TRACP-5b should decrease by approximately 30% with effective sequential therapy 4
• Useful for assessing compliance and pharmacologic response 1
• Target: at or below the median value for premenopausal women 1

Clinical Monitoring

• Assess for new fractures at each visit (vertebral and non-vertebral)
• Calcium and vitamin D supplementation: Continue daily throughout sequential therapy 2
• Monitor serum calcium if using denosumab (risk of hypocalcemia, especially with renal impairment) 8

Critical Pitfalls to Avoid

If Denosumab is Chosen

Never discontinue denosumab without immediate transition to another antiresorptive (preferably bisphosphonate for at least 1-2 years) 1, 5, 6. Stopping denosumab causes:

• Rapid rebound in bone turnover within 6-9 months
• BMD decline to pretreatment levels by 18-24 months
• Increased risk of multiple vertebral fractures 8, 3

Denosumab must be given every 6 months without delay—missed doses trigger rebound bone loss 8.

If Bisphosphonate is Chosen

• Oral bisphosphonates require proper administration (fasting, upright position for 30-60 minutes) to ensure absorption
• If oral absorption or adherence is a concern, use IV zoledronic acid 5, 6

Patients Without Sequential Therapy

Real-world data show that patients who did not receive sequential therapy after romosozumab experienced:

• 5.4% BMD loss at lumbar spine from year 1 to 2
• 15.4% fracture rate (vs. 6.3% with sequential therapy) 4

Duration of Sequential Therapy

Continue antiresorptive therapy long-term as clinically appropriate:

• Bisphosphonates: Consider reassessment after 3-5 years for potential drug holiday only if fracture risk is no longer high (T-score >-2.5, no new fractures) 1
• Denosumab: No drug holiday recommended—continue indefinitely or transition to bisphosphonate if discontinuation is necessary 1, 8

Special Considerations

If New Fracture Occurs During Sequential Therapy

• Reassess fracture risk and consider switching to a different class of osteoporosis medication 5, 6
• Options include switching between denosumab and bisphosphonates, or considering another anabolic agent if appropriate

Cardiovascular Monitoring

While romosozumab carries a black-box warning for cardiovascular events, this risk does not persist after discontinuation 3. However, continue standard cardiovascular risk management.

Retreatment with Romosozumab

Future retreatment with romosozumab may be possible, though evidence is limited 3.