About Hypoxemia

Hypoxemia is an abnormally low level of oxygen in the blood. Hypoxemia has many causes, including pulmonary disorders like idiopathic pulmonary fibrosis (IPF).

IPF is characterized by irreversible, progressive scarring of the lungs. As a patient's lung scarring worsens, the lungs cannot properly move oxygen into the bloodstream and, as a result, the body’s tissues do not get the oxygen they need. The cause of IPF is unknown and there is no cure. IPF inevitably causes shortness of breath and destruction of healthy lung tissue, resulting in hypoxemia, tissue hypoxia, and ultimately organ dysfunction.

Patients with IPF typically experience progressive worsening of lung function over time, requiring the use of supplemental oxygen and frequent hospitalizations in the late stages of the disease. Supplemental oxygen therapy is a well-established treatment for IPF, but is associated with a significant burden on the patients’ quality of life due to demands of the delivery equipment that ultimately can lead to significantly impaired mobility and psychosocial decline. A drug that has the potential to improve oxygenation could fill a significant unmet medical need. 


GBT is developing GBT440 as an oral, once-daily therapy for patients with sickle cell disease (SCD) and for the potential treatment of hypoxemic pulmonary disorders, including IPF. GBT440, a hemoglobin modifier, is designed to work by increasing hemoglobin's affinity for oxygen. To date, we have established proof of concept for GBT440 analogs in three different animal models of hypoxia. Emerging data suggest that hemoglobin modifiers such as GBT440 have the potential to restore normal hemoglobin function and increase oxygen uptake in the lungs, resulting in improved oxygen delivery to tissues.

Clinical Trials

We have two ongoing Phase 2a studies in adults with idiopathic pulmonary fibrosis (IPF) – one in people who become hypoxemic on exertion and one in people who are dependent on oxygen when resting, called ZEPHYR. We also have a Phase 1 clinical trial, called Basecamp, which is evaluating the physiologic effects of GBT440 in fit healthy volunteers under hypoxic conditions and exercise conditions that maximally stress the function of the heart and lungs.

Click here to access information on the Phase 2a study in adults with IPF who have low blood oxygen levels when they exercise on

Click here to access information on ZEPHYR, the Phase 2a study in adults with IPF who need oxygen while resting on

Click here to access information on Basecamp, the Phase 1 study in healthy volunteers on

Additional Resources

In an effort to provide patients and their families with access to the latest and most valuable resources related to IPF, we have compiled the following list of links. These links will take you away from the company’s website, but connect you to other trusted providers of information that we think may be useful to patients and their families.

Patient Advocacy Groups:

Pulmonary Fibrosis Foundation Centers of Excellence:

Scientific Societies/Organizations:

Additional Resources for IPF Information:

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