The trial (NCT02160730), at Cedars-Sinai Medical Center in Los Angeles, will evaluate whether seliciclib can safely suppress the production of adrenocorticotropic hormone (ACHT) secreted by the pituitary tumors, normalizing levels of cortisol in urine.
Researchers will also assess the impact of seliciclib treatment in tumor size.
The molecule has been tested in several Phase 1 and 2 clinical trials as a treatment for solid tumors, where it showed promising anti-tumor activity.
Researchers now hypothesize that seliciclib could also reduce the growth of pituitary tumors, helping control the symptoms of Cushing’s disease.
In mice with ACTH-secreting pituitary tumors, oral administration of seliciclib reduced tumor weight by 50%, which significantly reduced plasma ACTH levels and blood cortisol levels.
The findings supported the initiation of the Phase 2 clinical trial in patients with Cushing’s disease, a condition where ACTH-secreting pituitary tumors increase cortisol levels in the blood.
The proof-of-concept Phase 2 trial is being conducted in collaboration with the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health.
The study is expected to enroll approximately 16 adult patients with excessive production of ACTH hormone due to a pituitary tumor. Patients with Cushing’s disease due to other causes are not eligible to participate.
For more information, go to the clinical trial’s registry webpage by visiting this link.
Participants will receive 400 mg of oral seliciclib twice daily, four days a week, for a total treatment duration of four weeks.
The primary goal of the study is to determine if the treatment normalizes the levels of cortisol in patients’ urine. It will also evaluate the treatment’s safety and tolerability, as well as changes in clinical symptoms, such as weight, body mass index, and blood pressure.
In addition, researchers will measure the impact of seliciclib in pituitary hormones, such as testosterone, TSH, FT3, PRL, and others.
The study is expected to be completed by December 2019, and preliminary results are anticipated by the end of 2018.