Prospective Treatment Efficacy in IPF Using Genotype for Nac Selection (PRECISIONS) Trial (PRECISIONS)

  • End date
    Sep 15, 2025
  • participants needed
  • sponsor
    Weill Medical College of Cornell University
Updated on 27 May 2022
forced vital capacity


The purpose of this study is to compare the effect of n-acetylcysteine (NAC) plus standard care with matched placebo plus standard of care in patients diagnosed with idiopathic pulmonary fibrosis (IPF) who have the TOLLIP rs3750920 TT genotype. The study will compare the time to a composite endpoint of relative decline in lung function [10% relative decline in forced vital capacity (FVC), first respiratory hospitalization, lung transplantation, or all-cause mortality]

The secondary objectives will be to examine the effect of NAC on the components of the primary composite endpoint, the rates of clinical events, change in physiology, change in health status, and change in respiratory symptoms.


This is a multi-center, randomized, double-blind, placebo-controlled trial of NAC or placebo in about 200 participants with IPF with a TOLLIP rs3750920 TT genotype.

Eligible participants will be randomized in a 1:1 fashion to NAC or placebo, stratified by stable concomitant IPF therapy use (i.e., pirfenidone or nintedanib administered for at least 6 weeks prior to screening) versus no pirfenidone or nintedanib use. Participants will receive 600 mg NAC orally or matched placebo to take three times daily for 24 months.

Condition Idiopathic Pulmonary Fibrosis
Treatment Placebo, N-Acetyl Cysteine
Clinical Study IdentifierNCT04300920
SponsorWeill Medical College of Cornell University
Last Modified on27 May 2022


Yes No Not Sure

Inclusion Criteria

≥ 40 years of age
Diagnosed with IPF according to 2018 ATS/ERS/JRS/ALAT, confirmed by enrolling investigator
Signed informed consent
If taking pirfenidone or nintedanib, must be on stable dose for at least 6 weeks prior to enrollment visit
Confirmed rs3570920 TT TOLLIP genotype

Exclusion Criteria

Pregnancy or planning to become pregnant
Women of childbearing potential not willing to remain abstinent (refrain from heterosexual intercourse) or use two adequate methods of contraception, including at least one method with a failure rate of <1% per year during study participation
Significant medical, surgical or psychiatric illness that in the opinion of the investigator would affect subject safety, including liver and renal failure
Receipt of an investigational drug or biological agent within the previous 4 weeks of the screening visit or 5 times the half-life, if longer
Supplemental or prescribed NAC therapy within 60 days of enrollment
Listed for lung transplantation at the time of screening
History of lung cancer
Inability to perform spirometry
Forced vital capacity (FVC) less than 45% predicted, using the global lung function index (GLI) equation at Visit 1
Active respiratory infection requiring treatment with antibiotics within 4 weeks of Visit 1
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