Phase 2 Trial of RXC007, Oral ROCK2 Inhibitor for IPF, Being Planned
RXC007, an experimental oral treatment of idiopathic pulmonary fibrosis (IPF) being developed by Redx Pharma, continues to be safe and well-tolerated in a Phase 1 study in healthy volunteers, the company reported.
“Clinical data from our Phase 1 study suggests that RXC007 is safe and well-tolerated at the drug doses we have selected,” Lisa Anson, Redx’s CEO, said in a press release.
Supported by the findings, Redx is planning to launch a 12-week Phase 2a trial in patients this year that will compare various doses of RXC007 against a placebo, with and without standard-of-care treatment.
The aim of the Phase 2a study is to evaluate the safety and preliminary efficacy of RXC007 in people with IPF, as well as to determine the optimal dose for future trials. A proposed Phase 2b trial would assess RXC007, when given along with standard-of-care agents, on patients’ lung function over the course of one year, the company reported.
RXC007 is designed to block the activity of Rho-associated protein kinase 2 (ROCK2), a protein that plays a central role in the progression of fibrosis, or tissue scarring, in IPF and other diseases.
According to Redx, this protein has been a “notoriously difficult target,” in part because it is hard to block ROCK2 without also blocking a related protein called ROCK1, which can lead to abnormally low blood pressure or hypotension. RXC007 is expected to avoid this side effect by being “potent and highly selective,” inhibiting ROCK2 but not ROCK1.
To date, some participants have been given a single dose of RXC007, with capsules ranging in dose from 2 to 70 mg (given once or twice that day). To date, there have been no side effects reported with any of the single doses tested.
Other participants have been given 50 mg of RXC007 twice daily for 14 days. This multiple dose regimen has also been generally well-tolerated, with transient and reversible side effects reported.
Pharmacological data have generally been in line with expectations from preclinical models, and suggest that medication levels in the body are high enough to achieve an anti-fibrotic effect. There was a near-linear exposure relationship across the range of doses tested, meaning that higher doses of the medication led to consistently higher levels of the therapy in the body.
The therapy’s half-life, or the time it takes for the amount of its active ingredient to be processed and drop to half, appeared to be around nine to 11 hours. This suggests that RXC007 is likely suitable for once-daily dosing, according to Redx.
“Importantly, this data supports progressing into Phase 2 studies later this year to assess the safety and efficacy of RXC007 in patients with idiopathic pulmonary fibrosis, a disease with high unmet medical need,” Anson said.