Enrollment now complete for 2nd Phase 3 trial of pamrevlumab in IPF

Results from FibroGen study ZEPHYRUS-2 expected in mid-2024

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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ZEPHYRUS-2, the second Phase 3 clinical trial testing the experimental therapy pamrevlumab in people with idiopathic pulmonary fibrosis (IPF), has finished recruiting patients, according to its developer FibroGen.

“We are pleased to announce the completion of enrollment for our second Phase 3 study of pamrevlumab in IPF,” Mark Eisner, MD, chief medical officer of FibroGen, said in a company press release.

Top-line results from ZEPHYRUS-2 (NCT04419558) are expected in mid-2024, according to FibroGen. The study enrolled a total of 372 people with IPF, ages 40-85, who were not currently using any approved IPF treatments.

Trial participants will be randomly assigned to receive either pamrevlumab or a placebo, administered via an infusion into the bloodstream every three weeks for about one year. The pamrevlumab dose to be given is 30 milligrams per kilogram of body weight.

The study’s main goal is to assess the impact of treatment on forced vital capacity (FVC), a common lung function measure that evaluates how much air a person can exhale after a deep breath. Other lung function measures, as well as survival outcomes and safety data, also will be assessed.

IPF … patients need new treatment options to improve their clinical outcomes.

An identically designed Phase 3 clinical trial called ZEPHYRUS-1 (NCT03955146) also is ongoing. It finished enrolling 356 people with IPF last year, and top-line results are expected later this year.

Participants in both ZEPHYRUS trials will have the option to enter an open-label extension phase, in which all will be treated with pamrevlumab and monitored for long-term outcomes.

“The ZEPHYRUS program consists of two phase 3 clinical trials that will evaluate the ability of pamrevlumab to attenuate fibrosis and lung function decline in patients with idiopathic pulmonary fibrosis,” Eisner said. “IPF is a fatal progressive disease, and patients need new treatment options to improve their clinical outcomes.”

IPF is characterized by scarring, or fibrosis, in the lungs. Lung tissue is normally stretchy, allowing for the lungs to expand and fill with air every time a person inhales. Scarring causes lung tissue to become stiffer and interferes with the lungs’ ability to function.

Pamrevlumab is an antibody-based therapy designed to block the activity of connective tissue growth factor (CTGF), a signaling molecule that helps drive scar tissue formation.

Data from two previous Phase 2 trials, called PRAISE (NCT01890265) and FGCL-3019-049 (NCT01262001), suggested the therapy could reduce fibrosis and slow lung function decline.

A 2020 comparison of Phase 2 data with findings from clinical trials of other therapies hinted that pamrevulmab might be more effective than available IPF treatments.