Pearl: Teriparatide had and abaloparatide has a black box warning for risk of osteosarcoma due to an increase incidents in rats. So far, the rates of osteosarcoma have not been higher than expected in the general population.

Teriparatide and abaloparatide originally came with a black box warning.  In rats, there was an “increase in the incidence of osteosarcoma.”  Teriparatide’s black box warning was removed and abaloparatide is in review.

Sources: Abaloparatide package insert, Teriparatide package insert

Selected risk factors for osteosarcoma

• Prior bone malignancy
  • Note: teriparatide is contraindicated (see Teriparatide [Human PTH(1-34)]: 2.5 years experience on the use and safety of the Drug for the treatment of osteoporosis) in patients with cancer and known bone metastasis (including any ER+ breast cancer)
  • For more reading on bone health in cancer survivors see Individualized Bone-Protective Management in Long-Term Cancer Survivors With Bone Metastases
• Paget’s disease of the bone (suspect in elevated alkaline phosphatase)
• Pediatric and young adult patients with open epiphyses
• Patients with any prior external beam or implant radiation

In post marketing surveillance, the rates of osteosarcoma have not been higher than expected in the general population.

However, teriparatide and abaloparatide should be reserved for patients in which the benefits of therapy outweigh the potential risk of osteosarcoma “because of the uncertain relevance of the rat osteosarcomas”

Further, no more than two years of therapy is recommended.