Global Blood Therapeutics (GBT) recently announced it has enrolled the first patient into its Phase 2 ZEPHYR clinical trial (NCT02846324), assessing the safety and effectiveness of GBT440 in treating hypoxemia in patients with idiopathic pulmonary fibrosis (IPF) who receive supplemental oxygen at rest.

Hypoxemia is a condition referring to abnormally low levels of oxygen in the blood. It is common for IPF patients to suffer from hypoxemia, and often causes patients to feel breathless and fatigue.

GBT440 is a modifier that works by increasing hemoglobin’s affinity for oxygen.

According to a press release, recent research suggests that hemoglobin modifiers like GBT440 have the potential to restore hemoglobin function and increase oxygen uptake in the lungs, resulting in improved oxygen delivery to tissues.

In animal models, GBT440 demonstrated increased oxygen saturation levels in pulmonary fibrosis and severe hypoxia. Based on these findings, GBT440 is now being evaluated for its potential in treating hypoxemia in IPF patients.

The ZEPHYR clinical trial was designed as an open-label study to evaluate GBT440 in a broad range of patients with IPF, including those who are on supplemental oxygen at rest and patients who do not use oxygen at rest but become hypoxemic with exercise.

The trial will evaluate 16 IPF patients who are receiving supplemental oxygen at rest, ages 45 to 80. Each will receive 900 mg of oral treatment on a daily basis.

“Although supplemental oxygen is an important treatment for IPF patients with hypoxemia, it’s also a burden due to the mobility restrictions posed by oxygen delivery devices and as a result adherence to therapy may be limited,” said Ted W. Love, MD, GBT’s president and CEO. “Allowing patients to be oxygen-independent or reducing their need for oxygen would be very beneficial for this patient population.”

The trial’s primary endpoint will be the evaluation of the effects of GBT440 on oxygen saturation at rest over 90 days. Secondary endpoints include evaluating the effect of GBT440 on the requirement of supplemental oxygen, the six-minute walk distance (6MWD) test (which assesses exercise capacity), and overall quality of life using patient-reported outcomes. The study will also evaluate the tolerability and pharmacokinetics of GBT440.

“This Phase 2a study will provide further important evidence to validate GBT440’s unique hypoxemia-targeting mechanism of action. We believe that GBT440 has the potential to be a promising therapeutic option for IPF patients,” Love said.