Short answer: Both are injections given by a healthcare provider for osteoporosis at high fracture risk. Prolia (denosumab) is 60 mg every 6 months and slows bone turnover; it is approved for women and men. Evenity (romosozumab) is 210 mg once a month for 12 doses and builds bone; it is approved for postmenopausal women only.12 No trial has compared the two.
| Prolia (denosumab) | Evenity (romosozumab) | |
|---|---|---|
| What it is | RANK ligand (RANKL) inhibitor1 | Sclerostin inhibitor2 |
| Approved for | Postmenopausal women and men with osteoporosis at high fracture risk; steroid-induced osteoporosis; bone loss in men on hormone therapy for prostate cancer and women on aromatase inhibitors for breast cancer1 | Postmenopausal women with osteoporosis at high fracture risk2 |
| Label dose | 60 mg under the skin once every 6 months, in the upper arm, upper thigh or abdomen1 | 210 mg under the skin once a month, given as two 105 mg injections one after the other2 |
| How long | No set limit. Stopping raises fracture risk; move to another bone drug if stopped1 | 12 monthly doses only, because the bone-building effect wanes; then a bone-loss drug may follow2 |
| Boxed warning | Severe low calcium in advanced kidney disease (eGFR under 30), including dialysis1 | Possible higher risk of heart attack, stroke and cardiovascular death; not started within a year of a heart attack or stroke2 |
| Main placebo trial | 3 years: new spine fractures 2.3% vs 7.2% on placebo; hip fractures 0.7% vs 1.2%1 | 12 months: new spine fractures 0.5% vs 1.8% on placebo2 |
| Calcium and vitamin D | Calcium 1,000 mg and at least 400 IU vitamin D daily1 | Adequate calcium and vitamin D during treatment2 |
| Missed dose | Give as soon as possible, then every 6 months from that date1 | Give as soon as it can be rescheduled, then monthly from that date2 |
| Blood levels | Mean half-life 25.4 days; levels fall over 4 to 5 months1 | Peak about 5 days after a dose; steady level by month 32 |
| Storage | Refrigerated; once out, keep at or below 77°F and use within 30 days1 | Refrigerated; once out, keep at or below 77°F and use within 30 days2 |
Each label reports its own trials in postmenopausal women:
These numbers come from separate placebo-controlled trials with different people, lengths and methods, so they are not a head-to-head comparison. In Evenity's Study 1, denosumab (the drug in Prolia) was given after Evenity, so that trial tested a sequence, not one drug against the other.2
In the trial against alendronate, heart attack, stroke or cardiovascular death occurred in 2.0% of women in the first 12 months on Evenity vs 1.1% on alendronate (hazard ratio 1.87). In the placebo trial the rate was 0.8% in both groups.2 The label says not to start Evenity within a year of a heart attack or stroke, and to stop it if one happens.2
The Prolia label warns that fracture risk rises after stopping, including multiple spine fractures. Bone turnover climbs above pretreatment levels about 9 months after the last dose, and new spine fractures were seen as early as 7 months (on average 19 months) after it. The label says to move to another bone-loss drug if Prolia is stopped.1 Evenity is limited to 12 doses by design, and its label suggests a bone-loss drug after that if treatment is still needed.2
More detail: Prolia side effects, Evenity side effects, the Prolia and Evenity dosing schedules, and what to do if you miss a Prolia shot or miss an Evenity dose.