- An experimental drug from Ionis Pharmaceuticals succeeded in a Phase 3 trial in the rare disease hereditary angioedema, positioning the company and partner Otsuka to seek regulatory approvals in the U.S. and Europe.
- The medicine, called donidalorsen, reduced the rates of swelling attacks associated with the disease when given every one or two months, Ionis said Monday. Results showed a statistically significant benefit over placebo on secondary measures, too. No serious adverse events were reported in treated patients, according to Ionis.
- Ionis disclosed only summary data, leaving unanswered questions about the magnitude of donidalorsen’s effect and how it might compare to other medicines. Later this year, Ionis will present detailed findings as well as results from another late-stage study that enrolled people who switched to Ionis’ drug after taking another medicine.
Monday’s announcement marks a step in Ionis’ transformation. A pioneering developer of RNA-based medicines called antisense oligonucleotides, the company previously favored licensing out its products instead of bringing them to market itself.
However, Ionis has shifted strategy under CEO Brett Monia, aiming instead to capitalize on the sales upside of its newer medicines. Those drugs use a technology known as LICA, which is meant to make them safer and more potent than previous antisense oligonucleotides.
The approach has paid dividends, as three of Ionis’ rare disease treatments have succeeded in late-stage testing over the last year. One, sold as Wainua, has reached market. At about $50 apiece, Ionis shares are trading at their highest levels since early 2021.
“We are now well on our way to independently launching medicines from our wholly owned pipeline,” said Monia, in a statement.
Still, Ionis isn’t consistently profitable. It recorded a net loss of $357 million through the first nine months of 2023 after posting $270 million in losses a year earlier. Wainua, a key asset for Ionis, competes with a rival Alnylam Pharmaceuticals medicine.
Donidalorsen, meanwhile, is one of many being developed to prevent the swelling attacks associated with HAE, a rare, inherited condition estimated to affect one in 50,000 people around the world. While HAE drugs are available from Takeda, CSL and others, they don’t ward off attacks completely.
It’s unclear whether Ionis’ drug is better than available, preventive medicines like Takeda’s injectable Takhzyro or Biocryst Pharmaceuticals’ pill Orladeyo. Ionis is also developing donidalorsen at a time when other preventive options are advancing through clinical testing, among them a new antibody drug from CSL, an oral treatment from Pharvaris and a gene editing therapy from Intellia Therapeutics.
One of the questions donidalorsen faces is whether the Phase 3 results meet the “high bar” it achieved in mid-stage testing, according to Stifel analyst Paul Matteis.
“We'll need to see detailed donidalorsen data to fully understand differentiation,” Matteis wrote in a Monday note to clients. “The HAE space is highly competitive,” he noted, adding that “the market is fragmented: some patients are willing switchers whereas others are sticky and brand loyal.”
Ionis holds U.S. rights to the drug. Otsuka acquired European rights in December.