A Phase 2 Study to See if Simtuzumab (GS-6624) is Safe and Works in Idiopathic Pulmonary Fibrosis (IPF)

Inclusion Criteria:

- Male or female subjects from 45 to 85 years of age

- Definite IPF within 3 years prior to screening

- Be able to walk at least 50 meters

Exclusion Criteria:

- Significant diseases other than IPF

- Obstructive lung disease

- Aortic aneurysm greater than or equal to 3.5 cm in diameter

- Treatment with immunosuppressive, cytotoxic, or antifibrotic drugs < 28 days prior to
randomization are not permitted.

- N-acetylcysteine is permitted provided the individual has been on a stable dose
for > 4 weeks prior to screening

- Concomitant use of pirfenidone or nintedanib must be in accordance with the
approved prescribing instructions in the country where the site is located

- Individuals actively listed for lung transplant are excluded. However individuals at
transplant centers with long waiting times (greater than 1 year) may be permitted to
enter the study after discussion with Medical Monitor.