
Alnylam boasts PhII win in kidney disease cornerstone of Regeneron R&D blockbuster deal
A drug at the heart of the $1 billion-plus Alnylam and Regeneron collaboration cemented three years ago has some new efficacy data to show off.
The RNAi biotech once helmed by John Maraganore reported positive topline data Thursday for its investigational cemdisiran, an RNAi drug targeting the C5 component of the pathway that both Alnylam and Regeneron are working on in IgAN, or immunoglobulin A nephropathy. The data come out of a Phase II descriptive trial, with no statistical hypothesis testing.
Immunoglobulin A nephropathy is a kidney disease, marked by when immunoglobulin A, an antibody, builds up in the kidneys. This can result in inflammation and ultimately kidney failure.
After 32 weeks, treatment in 31 adult patients with subcutaneously administered cemdisiran resulted in a 37% mean reduction from baseline in the 24-hour urine protein to creatinine ratio (UPCR) relative to placebo. As such, the study reached its primary endpoint of precent change in the UPCR after 24 hours.
The results of secondary endpoints were also “consistent with a therapeutic benefit of cemdisiran in IgAN,” according to Alnylam. Those secondary endpoints:
- Percent of patients with partial clinical remission (urine protein <1g/24-hours)
- Percent of patients with >50% reduction in 24-hour proteinuria
- Percent change from baseline in 24-hour proteinuria (g/24-hours)
- Change from baseline in UPCR as measured in spot urine
- Change from baseline in hematuria
- Frequency of adverse events (AEs)
Alnylam said there were no “significant drug-related safety signals,” but noted that two of nine patients on placebo and 12 of 22 patients on cemdisiran experienced treatment-emergent adverse events.
Shares of $ALNY dipped slightly after the release, going down less than 1% after the announcement.

“We are encouraged by these topline results with cemdisiran demonstrating what we believe to be clinically meaningful reductions in proteinuria – an important prognostic factor in IgA nephropathy,” said Alnylam VP and Cemdisiran program leader Sonalee Agarwal in a statement.
Agarwal added that Alnylam and Regeneron are working on putting together plans for Phase III clinical development. Full results will be presented at a future medical congress.
When the deal was first inked in 2019, Regeneron had agreed to pay Alnylam $400 million upfront, and added another $400 million equity — equating to $90.01 a share in 2019 — with $200 million on the table in early clinical milestones. With up to 30 targets in mind, Alnylam was offered to get a $2.5 million bonus every time it initiated a program, another $2.5 million for lead identification and about $30 million in annual discovery funds available to boot.