Efzofitimod found safe, well tolerated in study of SSc-ILD

Results of separate trial for pulmonary sarcoidosis expected next month
by Marisa Wexler, MS | August 12, 2025

Efzofitimod was found to be generally safe and well tolerated by patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) in a proof-of-concept Phase 2 study. No treatment-related serious side effects were reported, with efzofitimod showing early signs of efficacy.

In addition, the last patient visit has been completed in EFZO-FIT, a Phase 3 clinical trial testing aTyr Pharma’s investigational therapy in people with pulmonary sarcoidosis.

Results from the Phase 3 study are expected next month, according to a corporate update from aTyr.
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“With the recent completion of the last patient visit in our Phase 3 EFZO-FIT study of efzofitimod in pulmonary sarcoidosis … we are on track to report topline data in mid-September,” said Sanjay S. Shukla, MD, president and CEO of aTyr. “This upcoming readout represents a major inflection point for aTyr, our clinical program for efzofitimod … and the broader sarcoidosis community, and we look forward to sharing the results.”

Patients showed stable or reduced skin thickening
Sarcoidosis is a disorder marked by abnormal clumps of inflammatory immune cells. In pulmonary sarcoidosis, these immune cell clumps specifically form in the lungs.

A proof-of-concept Phase 2 study called EFZO-CONNECT (NCT05892614) is testing efzofitimod against a placebo in people with interstitial lung disease associated with systemic sclerosis (SSc-ILD). The disorder is marked by inflammation and fibrosis, or scarring, in the lungs of people with sarcoidosis affecting organs throughout the body.

In this trial, participants are randomly assigned to receive monthly intravenous doses of efzofitimod (270 mg or 450 mg) or a placebo for six months. The study, which aims to enroll up to 25 adults at sites across the U.S., is still enrolling adults with SSc-ILD at several sites.

Recent interim results from the first eight participants showed efzofitimod was generally safe and well tolerated, with no treatment-related serious side effects. All patients showed stable or reduced skin thickening, and most of those with diffuse SSc-ILD showed a meaningful improvement in their modified Rodnan Skin Score — a key measure of skin fibrosis. Blood tests also suggested early signs of lower levels of inflammation-related proteins, as well as disease-related markers.

Study tests whether efzofitimod can reduce need for oral corticosteroids
Efzofitimod is designed to inhibit neuropilin-2 (NRP2), a protein that plays a key role in the activation of certain inflammatory immune cells that have a central role in sarcoidosis. This means the therapy could help lower lung inflammation and prevent or slow scarring.

Data from an earlier Phase 1/2 trial (NCT03824392) indicated the therapy improved lung function and eased symptoms in pulmonary sarcoidosis patients.

The Phase 3 EFZO-FIT study (NCT05415137) that just completed its last patient visit enrolled 268 people with pulmonary sarcoidosis at 85 centers across nine countries. Participants were randomly assigned to receive efzofitimod at one of two doses (3 mg/kg or 5 mg/kg), or a placebo, administered monthly by infusion into the bloodstream.

The study’s main goal is to see if efzofitimod can reduce the need for oral corticosteroids after about a year of treatment. Corticosteroids are a class of anti-inflammatory therapy that’s commonly used to manage sarcoidosis, but long-term corticosteroid treatment can lead to unwanted side effects like mood changes and weight gain. The EFZO-FIT study will also evaluate the impact of treatment on measures of lung function and symptom severity.
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Patients who finish the study and still want to keep taking efzofitimod may be able to get it through an Individual Patient Expanded Access Program that provides the treatment outside of the clinical trial.