Short answer: Both build bone in osteoporosis at high fracture risk. Evenity (romosozumab) is 210 mg once a month for 12 doses, given by a healthcare provider, for postmenopausal women only, with a boxed heart warning. Forteo (teriparatide) is a 20 mcg daily self-injection, also approved for men and steroid-induced osteoporosis.12 One trial compared them on bone density.
| Evenity (romosozumab) | Forteo (teriparatide) | |
|---|---|---|
| What it is | Sclerostin inhibitor (antibody)1 | Parathyroid hormone analog, PTH(1-34)2 |
| Approved for | Postmenopausal women with osteoporosis at high fracture risk1 | Postmenopausal women at high fracture risk; men with primary or hypogonadal osteoporosis; steroid-induced osteoporosis in men and women2 |
| Label dose | 210 mg once a month as two 105 mg shots, given by a healthcare provider1 | 20 mcg under the skin once a day, self-injected2 |
| How long | 12 monthly doses only, because the bone-building effect wanes1 | More than 2 years in a lifetime only if fracture risk stays or becomes high again2 |
| Boxed warning | Possible higher risk of heart attack, stroke and cardiovascular death; not started within a year of a heart attack or stroke1 | None; osteosarcoma in rats is listed as a warning2 |
| New spine fractures, main placebo trial | 0.5% vs 1.8% at 12 months1 | 5.0% vs 14.3%, median 19 months2 |
| STRUCTURE (head to head, total hip bone density at 12 months) | +2.6%3 | −0.6%3 |
| Storage | Refrigerated; once out, keep at or below 77°F and use within 30 days1 | Refrigerated at all times except when injecting; pen discarded 28 days after first use2 |
Yes, for bone density. The STRUCTURE trial randomized 436 postmenopausal women with osteoporosis and a past fracture, who had taken an oral bisphosphonate for at least 3 years, to romosozumab 210 mg monthly or teriparatide 20 mcg daily for 12 months, open label. Total hip bone density changed +2.6% on romosozumab vs −0.6% on teriparatide (difference 3.2 points).3
High calcium was reported in under 1% on romosozumab vs 10% on teriparatide. Serious adverse events were 8% vs 11%. The trial measured bone density, not fractures, and only in women coming off bisphosphonates.3
In Evenity's Study 1, 7,180 postmenopausal women had new spine fractures in 0.5% vs 1.8% on placebo over 12 months. In Study 2, Evenity for a year then alendronate, vs alendronate alone, gave 4.1% vs 8.0% through month 24.1 In Forteo's trial of 1,637 women, new spine fractures were 5.0% vs 14.3% over a median 19 months.2
These numbers come from separate placebo-controlled trials with different people, lengths and methods, so they are not a head-to-head comparison. 90% of women in the Forteo trial already had a spine fracture at the start.2
In Evenity's trial against alendronate, heart attack, stroke or cardiovascular death occurred in 2.0% in the first 12 months vs 1.1% on alendronate (hazard ratio 1.87). In the placebo trial it was 0.8% in both groups.1 The label says not to start Evenity within a year of a heart attack or stroke. Forteo's label has no such warning; it lists osteosarcoma seen in rats and says to avoid Forteo in people at higher risk of it.2
More detail: Evenity side effects, Forteo side effects, the Evenity and Forteo dosing schedules, what to do if you miss an Evenity dose or miss a Forteo dose, how to store Forteo, and the Teriparatide guide.