From the Guidelines
Forteo (teriparatide) carries a small but notable risk of osteosarcoma, a rare bone cancer, which was observed in rat studies when the medication was given at high doses for extended periods, but in humans, the actual risk appears to be extremely low, as evidenced by the lack of incident cases of osteosarcoma associated with use of this medication in the first 4 years of the voluntary Forteo Patient Registry safety study 1. The risk of cancer associated with Forteo (teriparatide) treatment for osteoporosis is a critical consideration, particularly given the black box warning on the medication due to the risk of osteosarcoma observed in animal studies 1. However, it is essential to weigh this risk against the benefits of fracture prevention in patients with severe osteoporosis.
Key Considerations
- The benefits of fracture prevention typically outweigh the theoretical cancer risk for patients with severe osteoporosis, as supported by high-quality evidence showing the efficacy of teriparatide in reducing the incidence of vertebral and non-vertebral fractures 1.
- Forteo treatment is limited to a lifetime maximum of 24 months and is contraindicated in patients with increased baseline risk for osteosarcoma, including those with Paget's disease of bone, unexplained elevations in alkaline phosphatase, open epiphyses, or prior radiation therapy involving the skeleton 1.
- Patients should be informed of this potential risk when considering Forteo as a treatment option for osteoporosis, and the decision to use teriparatide should be made on a case-by-case basis, taking into account the individual patient's risk factors and medical history 1.
Evidence Summary
- A postmarketing case series study encompassing 9 years of osteosarcoma cases found no patient reported use of teriparatide before diagnosis of osteosarcoma 1.
- The voluntary Forteo Patient Registry safety study found no incident cases of osteosarcoma associated with use of this medication in the first 4 years 1.
- High-quality evidence showed that teriparatide is associated with mild upper gastrointestinal symptoms, headache, and hypercalcemia, but no increased risk of osteosarcoma was observed 1.
From the FDA Drug Label
5 WARNINGS AND PRECAUTIONS 5. 1 Osteosarcoma An increase in the incidence of osteosarcoma (a malignant bone tumor) was observed in male and female rats treated with teriparatide. Osteosarcoma has been reported in patients treated with teriparatide in the post marketing setting; however, an increased risk of osteosarcoma has not been observed in observational studies in humans There are limited data assessing the risk of osteosarcoma beyond 2 years of teriparatide use
The risk of cancer, specifically osteosarcoma, associated with Forteo (teriparatide) treatment for osteoporosis is a potential concern, as it has been observed in rats and reported in some patients. However, no increased risk of osteosarcoma has been observed in adult humans treated with teriparatide. It is essential to note that there are limited data assessing the risk of osteosarcoma beyond 2 years of teriparatide use 2.
From the Research
Risk of Cancer with Forteo Treatment
The risk of cancer associated with Forteo (teriparatide) treatment for osteoporosis has been a topic of interest due to initial findings from pre-approval animal studies indicating an increased risk of osteosarcoma. However, subsequent human studies have not shown a significant increase in this risk.
Osteosarcoma Risk
- Studies have investigated the risk of osteosarcoma in patients treated with teriparatide, including those with a history of radiation therapy 3.
- Real-world studies using claims data have shown no increase in osteosarcoma in patients using teriparatide compared to unexposed groups 4.
- The Forteo Patient Registry Surveillance Study found no incident cases of osteosarcoma among patients registered, with a crude incidence rate of 0 cases per million person-years 5.
Regulatory Updates
- The label for Forteo was updated in 2020 to remove the boxed warning regarding the potential risk of osteosarcoma, based on real-world evidence and postmarketing data 4.
- The update also revised the 2-year lifetime limitation of use, taking into account the benefits and risks of teriparatide treatment.
Clinical Experience
- Teriparatide has been shown to be effective in reducing fractures and improving bone density in various patient groups, including post-menopausal and glucocorticoid-induced osteoporosis 6, 7.
- Real-world experience with teriparatide has confirmed the fracture and bone density benefits seen in clinical trials, with no safety signals relating to osteosarcoma identified in surveillance studies 7.