DISCONTINUED: Stages of Development for Calcitriol (vitamin D3)

The drug development process can be thought of as a series of stages, and drugs must successfully pass through each stage to become available to patients. This treatment has been evaluated, and the program has been discontinued. Thus, it is not in the pipeline.

Link to previous study

In primary cultures of frataxin-deficient dorsal root ganglia neurons, FXN protein was reduced by 50% of the control levels while FA lymphoblastoid cell lines showed a 60% reduction in FXN compared to cells obtained from healthy donors. IRBLleida (Institut de Recerca Biomèdica de Lleida Fundació Dr. Pifarré) team has shown that calcitriol can increase the production of frataxin up to 2.5 to 3 times.

Calcitriol was also able to significantly increase frataxin amounts in both frataxin deficient DRG neurons and lymphoblastoid cell lines.

Supplementing dorsal root ganglia neuronal cultures with 20nM calcitriol restored altered parameters such as mitochondrial membrane potential, calcium homeostasis and improved neuronal survival.

September 2021: An open label pilot study began to evaluate the effects of calcitriol in a small cohort of 20 individuals with FA. The study proposed to treat and monitor individuals for 12 months. Outcome measures of neurological function and blood frataxin levels were assessed throughout the study.

January 2023: The study was completed.

  • Calcitriol at a dose of 0.25mcg/24h increases frataxin levels in platelets from FA patients.
  • There were minimum side effects; however, 5 patients withdrew from the trial because of hypercalcemia.
  • There was no significant improvement in neurological function.