We have developed several unique functional antibody antagonists targeting PTH1R, a G-protein-coupled receptor involved in the regulation of calcium metabolism.

These antibodies have shown promising efficacy in in vivo studies and could potentially address high unmet medical needs, including hyperparathyroidisms (PHPT) and humoral hypercalcemia of malignancy (HHM).


Our PTH1R program began as an endocrine program, but its mechanism-of-action may be beneficial to oncology patients suffering from HHM. HHM is present in many advanced cancers and is caused by high serum calcium due to increased levels of the PTH1R ligand PTH-related peptide (PTHrP). Since current HHM treatments often fall short and many cancer patients die from ‘metabolic death’, our PTH1R antibodies could be very beneficial for the treatment of HHM.

Stage of Development

A development candidate has been selected based on extensive in vitro and in vivo preclinical testing. In April 2017, we presented positive data from pre-clinical studies investigating the activity of our anti-PTH1R antagonist monoclonal antibody at the American Association for Cancer Research (AACR) and the Endocrine Society (ENDO) annual meetings. Data presented at the AACR and ENDO conferences showed:

  • PTH1R antagonism in vitro by the anti-PTH1R mAb translated to potent in vivo activity
  • Our anti-PTH1R antagonist mAb has the potential to become a first-in-class therapy for HHM, as the data demonstrated it ameliorated hypercalcemia and associated morbidities in pre-clinical models
  • Our antibody libraries enabled the discovery of functional antibodies against a very complex target — i.e. the G-Protein Coupled PTH1Receptor
  • A high affinity fully human mAb to PTH1R has been selected and characterized
  • Proprietary antibody engineering resulted in antibodies with improved potency and manufacturing characteristics