Arcturus Therapeutics has offered an early snapshot of its inhaled mRNA therapy’s effects in cystic fibrosis, building its case for a delivery technology designed to transport mRNA to the lung.
The disclosure, which captured data from four patients with cystic fibrosis, sent Arcturus’ shares $ARCT up 26% on Tuesday, boosting its market cap to more than $1 billion.
So far, four patients have received Arcturus’ candidate, ARCT-032. After two administrations over eight days, they saw an average 4% absolute change in percent predicted forced expiratory volume in one second, or FEV1 — a metric to measure the severity of lung conditions.
CEO Joseph Payne called it “an encouraging trend towards lung function improvements” in a press release. The drug was also generally safe and well-tolerated, according to Arcturus, which will be presenting the results at a conference in early June. There, it will also share data from a separate Phase 1 study involving healthy volunteers.
While Vertex Pharmaceuticals’ suite of cystic fibrosis treatments has transformed the landscape for the majority of CF patients, some remain eligible for existing therapies. Vertex has partnered with Moderna to develop its own inhaled mRNA therapy for these patients, and other companies are trying other approaches, from small molecules to inhaled gene therapies.
William Blair analysts called Arcturus’ results “encouraging” but said key questions remain. For instance, it will be important to know if the 4% improvement in FEV1 is with or without background treatment on Vertex’s Trikafta. They are also watching for longer-term effects with more administrations and detailed safety data.