@loh naturally there are studies. That is why the black box warning was lifted. There is still a warning (see below from drug insert) but observational studies have not seen any osteosarcoma from use of Tymlos. That means no cases observed. Ditto with Forteo which has a similar mechanism. I had breast cancer in 2015 and had no concerns about taking Tymlos for two years. I needed it!

From the drug insert:

---------------------------RECENT MAJOR CHANGES------------------------
Osteosarcoma Boxed Warning, Removed 12/2021

Abaloparatide caused a dose-dependent increase in the incidence of osteosarcoma in male and female rats after subcutaneous administration at exposures 4 to 28 times the human exposure at the clinical dose of 80 mcg [see Nonclinical Toxicology (13.1)]. It is unknown whether TYMLOS will cause osteosarcoma in humans.

Osteosarcoma has been reported in patients treated with a PTH-analog 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 TYMLOS and/or use of a PTH-analog [see Dosage and Administration (2.3) and Nonclinical
Toxicology (13.1)].

Avoid use in patients with increased risk of osteosarcoma including patients with open epiphyses, metabolic bone diseases including Paget’s disease, bone metastases or history of skeletal malignancies, prior external beam or implant radiation therapy involving the skeleton, and hereditary disorders predisposing to osteosarcoma. (5.1)

Here is a study on Forteo: https://pmc.ncbi.nlm.nih.gov/articles/PMC9465003/

Subsequent investigations included five real‐world studies directed at assessing a connection between teriparatide and osteosarcoma risk in humans. The early studies did not identify an increased risk of osteosarcoma but were inadequate to sufficiently characterize risk, given the low incidence of this rare form of bone cancer. Learning from these efforts, two studies were undertaken using claims data to identify large cohorts of patients treated with teriparatide and assess whether these patients were found to have osteosarcoma by linking pharmacy claims data with data from cancer registries. These studies showed no increase in osteosarcoma in patients using teriparatide compared with unexposed groups, as well as to the expected population‐based background incidence of the disease. Based on this real‐world evidence and the totality of data collected from postmarketing use and other clinical investigations, the label was updated in 2020.