Phase 1 DRGT-45 Trial Doses First Patient With New Oral Formulation of Abiraterone Acetate

A Phase 1 clinical trial testing DRGT-45 — a new oral formulation of abiraterone acetate — in men with prostate cancer has dosed its first participant, the treatment’s developer, Druggability Technologies (DRGT), announced.

Abiraterone acetate is a form of hormone therapy already approved for men with advanced, castration-resistant prostate cancer, under the brand name Zytiga. That treatment, developed by Janssen Biotech, also is administered orally. However, due to its low solubility in water, patients need to ingest multiple large tablets to achieve the desired concentration.

Developed with DRGT’s proprietary Super-API technology platform, DRGT-45 is a new formulation of abiraterone acetate — tablets for oral suspension — designed to overcome this major limitation. Its increased solubility in water improves its bioavailability, or how much of it reaches the blood and is able to exert a therapeutic effect. The new formulation also decreases the impact of food on the treatment’s absorption.

Because the tablet is mixed with water, much like an aspirin tablet, patients don’t need to swallow a pill. That can significantly reduce the burden of taking the needed medication, particularly for those with difficulty swallowing – a condition affecting 20% of the general population.

In a prior Phase 1 clinical trial in healthy volunteers, data showed that DRGT-45 increased the exposure to abiraterone four-fold compared with the reference medicine Zytiga.  It also eliminated the food effect — which reduces abiraterone’s availability by up to 10 times — and reduced the exposure variability across individuals.

While the recommended dose of Zytiga is 1,000 mg administered orally once daily, the findings suggested that patients might achieve the same therapeutic effect with only 250 mg of DRGT-45.

“Our data suggests that DRGT-45 can mitigate the impact of food and allows for significant dose reduction while achieving a more predictable drug absorption,” John Friend, MD, chief medical officer at DRGT, said in a press release.

The newly launched, open-label Phase 1 trial will now test DRGT-45 in prostate cancer patients. It will particularly focus on the pharmacokinetic profile — how a drug behaves once inside the body — of escalating single doses of DRGT-45. Then, in a second part, the trial will compare the oral bioavailability of a single dose of DRGT-45 versus a single-dose of Zytiga, given before or after food.

Abiraterone acetate works by preventing the production of the male sex hormone androgen by irreversibly blocking the CYP17, an enzyme that is critical for testosterone and estrogen synthesis.