Global Blood Therapeutics is initiating a Phase 2a clinical trial to assess its oral drug GBT440, an investigational hemoglobin modifier, as a daily treatment for idiopathic pulmonary fibrosis (IPF) and hypoxemia.
Hypoxemia, or low blood oxygen levels, results in an insufficient amount of oxygen reaching the tissues (hypoxia). It is a leading cause of clinical decline in IPF patients.
GBT440 works by increasing hemoglobin’s affinity for oxygen, binding to 20% of the total hemoglobin in a patient’s blood. In preclinical trials, the treatment has been shown to increase oxygen saturation and uptake in the lungs. Global Blood Therapeutics is developing GBT440 for acute and chronic hypoxemic pulmonary disorders like IPF, and for sickle cell disease.
“Current treatment for IPF is targeted at slowing lung fibrosis but there has been no improvement in oxygenation and symptom burden of the disease. Supplemental oxygen therapy, which is used to treat the hypoxemia and its associated breathlessness, has local and systemic risks and poses a significant burden to patients,” Ted W. Love, MD, chief executive officer of Global Blood Therapeutics, said in a recent press release. “[T]here is a critical need for a therapeutic drug that can improve oxygenation without those risks.”
GBT440-006 is planned as a Phase 2a randomized, double-blind, and placebo-controlled trial in 18 IPF patients, who will receive one of two different doses of GBT440 or a placebo for 28 days. An additional 12 subjects may be enrolled following an independent safety review. Objectives include characterizing the safety, tolerability, and pharmacokinetics of the drug, and the change in oxygen saturation from baseline at rest and after exercise.
“Proof of concept has been established in three animal model studies suggesting that hemoglobin modification may increase oxygen saturation and improve oxygen delivery to tissues. Based on those data, we believe that GBT440 is a promising therapeutic option for IPF,” Dr. Love concluded.
IPF is a rare and poorly understood lung condition that causes scarring in the lungs, and its symptoms include shortness of breath and a persistent dry cough.