The results of a first-in-human phase I clinical trial with a new drug called PT2385 were presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago last week. PT2385 is an inhibitor of hypoxia inducible factor-2α (HIF-2α), a transcription factor implicated in the development and progression of kidney and other cancers.
In the phase I study, patients with advanced clear cell renal cell carcinoma (ccRCC), who had been treated with at least one prior VEGF inhibitor, were treated with PT2385 to determine the recommended phase II dose and evaluate safety, pharmacokinetics and pharmacodynamics. The phase I study showed PT2385 to be well tolerated with no dose-limiting side effects. PT2385 showed pharmacologic activity with encouraging clinical efficacy.
Among the 51 patients in total, the most common adverse events (AEs) were anaemia, peripheral oedema and fatigue. No cardiovascular AEs were noted. To date, one patient had a complete response, three patients had a partial response, and 16 patients had stable disease for 16 or more weeks. Ten percent of patients remain in this ongoing clinical trial for at least one year.
PT2385 is already undergoing clinical trials in combination with nivolumab (Opdivo), and the manufacturer, Peloton Therapeutics, are planning clinical studies of PT2385 as monotherapy and with other combination regimens.