FibroGen Announces Completion of Patient Enrollment in ZEPHYRUS-1, a Phase 3 Clinical Study of Pamrevlumab in Idiopathic Pulmonary Fibrosis

- 356 IPF Patients Enrolled -

- Topline Data Anticipated Mid-2023 -

SAN FRANCISCO, April 20, 2022 (GLOBE NEWSWIRE) -- FibroGen, Inc.,  (NASDAQ: FGEN) today announced completion of patient enrollment for ZEPHYRUS-1, the first of two Phase 3 clinical studies of pamrevlumab in patients with idiopathic pulmonary fibrosis (IPF), a chronic, progressive, and fatal lung disease.

“Completing patient enrollment for ZEPHYRUS-1 brings us closer to delivering evidence that pamrevlumab, an inhibitor of connective tissue growth factor (CTGF), provides clinical benefits for the treatment of IPF and other fibrotic disorders,” said Mark Eisner, M.D, M.P.H, Chief Medical Officer, FibroGen. “IPF is a fatal progressive disease, and patients need new treatment options to improve their clinical outcomes.”

Three hundred fifty-six (356) IPF patients have been enrolled into ZEPHYRUS-1, a randomized, double-blind, placebo-controlled, multi-center Phase 3 trial designed to evaluate the efficacy and safety of pamrevlumab in patients with IPF. The primary endpoint of the study is change from baseline in forced vital capacity (FVC). Top-line data from ZEPHYRUS-1 is anticipated in mid-2023. For more information about ZEPHYRUS-1 please visit (NCT03955146).

The Phase 3 clinical development program for pamrevlumab for IPF consists of two studies, ZEPHYRUS-1 and ZEPHYRUS-2. These trials are randomized, double-blind, placebo-controlled, multi-center Phase 3 trials designed to evaluate the efficacy and safety of pamrevlumab in patients with IPF. For more information about ZEPHYRUS-2, which is currently enrolling, please visit (NCT04419558).

About Pamrevlumab
Pamrevlumab is a potential first-in-class antibody being developed by FibroGen to inhibit the activity of connective tissue growth factor (CTGF), a common factor in fibrotic and proliferative disorders characterized by persistent and excessive scarring that can lead to organ dysfunction and failure. Pamrevlumab is in Phase 3 clinical development for the treatment of idiopathic pulmonary fibrosis (IPF), locally advanced unresectable pancreatic cancer (LAPC), and Duchenne muscular dystrophy (DMD). The U.S. Food and Drug Administration has granted Orphan Drug Designation (ODD), and Fast Track designation to pamrevlumab for the treatment of patients with IPF, LAPC, and DMD. The U.S. Food and Drug Administration has also granted Rare Pediatric Disease Designation to pamrevlumab for the treatment of patients with DMD. Pamrevlumab has demonstrated a safety and tolerability profile that has supported ongoing clinical investigation in IPF, LAPC, and DMD. Pamrevlumab is an investigational drug and not approved for marketing by any regulatory authority. For information about pamrevlumab studies currently recruiting patients, please visit  

About Idiopathic Pulmonary Fibrosis (IPF)        
Idiopathic pulmonary fibrosis is a chronic lung disease characterized by a progressive and irreversible decline in lung function in which lung tissue becomes damaged, stiff, and scarred. As tissue scarring progresses, transfer of oxygen into the bloodstream is increasingly impaired, leading to irreversible loss of lung function, as well as high morbidity and mortality. Average life expectancy is estimated to be three to five years from diagnosis with approximately two-thirds of patients dying within five years. Survival rates are comparable to those of some of the deadliest cancers.

Patients with IPF experience debilitating symptoms, including shortness of breath and difficulty performing routine functions, such as walking and talking. Other symptoms include chronic dry, hacking cough, fatigue, weakness, discomfort in the chest, loss of appetite, and weight loss. Over the last decade, refinements in diagnosis criteria and enhancements in high-resolution computed tomography imaging technology (HRCT) have enabled more reliable diagnosis of IPF without the need for a lung biopsy.

U.S. prevalence and incidence of IPF is estimated to be 135,000 cases (defined by ICD-9 code) and 21,000 new cases per year, respectively, based on Raghu et al. (Am J Respir Crit Care Med, 2006) and on data from the United Nations Population Division. We believe the number of patients will continue to grow due to heightened awareness and improved methods for detection and diagnosis.

About FibroGen
FibroGen, Inc. is a biopharmaceutical company committed to discovering, developing, and commercializing a pipeline of first-in-class therapeutics. The Company applies its pioneering expertise in connective tissue growth factor (CTGF) biology and hypoxia-inducible factor (HIF) to advance innovative medicines for the treatment of unmet needs. Pamrevlumab, an anti-CTGF human monoclonal antibody, is in clinical development for the treatment of idiopathic pulmonary fibrosis (IPF), locally advanced unresectable pancreatic cancer (LAPC), and Duchenne muscular dystrophy (DMD). The Company is currently developing and commercializing roxadustat, an oral small molecule inhibitor of HIF prolyl hydroxylase activity for anemia associated with chronic kidney disease (CKD), anemia associated with myelodysplastic syndromes (MDS), and for chemotherapy-induced anemia (CIA). FibroGen recently expanded its research and development portfolio to include product candidates in the immuno-oncology and autoimmune space. For more information, please visit

Forward-Looking Statements
This release contains forward-looking statements regarding our strategy, future plans and prospects, including statements regarding the development and commercialization of the company’s product candidates, the potential safety and efficacy profile of our product candidates, and our clinical programs. These forward-looking statements include, but are not limited to, statements about our plans, objectives, representations and contentions and are not historical facts and typically are identified by use of terms such as “may,” “will”, “should,” “on track,” “could,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “continue” and similar words, although some forward-looking statements are expressed differently. Our actual results may differ materially from those indicated in these forward-looking statements due to risks and uncertainties related to the continued progress and timing of our various programs, including the enrollment and results from ongoing and potential future clinical trials, and other matters that are described in our Annual Report on Form 10-K for the fiscal year ended December 31, 2021 filed with the Securities and Exchange Commission (SEC), including the risk factors set forth therein. Investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release, and we undertake no obligation to update any forward-looking statement in this press release, except as required by law.

FibroGen, Inc.

Michael Tung, M.D.
Corporate Strategy / Investor Relations

Meichiel Keenan
Director, Investor Relations & Corporate Communications


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