- Patients who meet any one of the following. Patients with a diagnosis of parathyroid carcinoma and corrected serum calcium > 11.3 mg/dL at the latest screening test. Patients with intractable PHPT (defined as follows: impossible to localize parathyroid tumor before initial surgery or in relapse after surgery, or impossible to perform parathyroidectomy (PTx) for complications, and corrected serum calcium is > 12.5 mg/dL at the screening test).