Sanofi’s $1.7 billion rare disease bet from last year has delivered a phase 2 win. In a midstage study, efdoralprin alfa beat the standard of care on primary and key secondary endpoints, positioning the drugmaker to talk to regulators about the next steps.
France’s Sanofi acquired the drug candidate from Inhibrx early last year. Shortly after news of the deal broke, Houman Ashrafian, Ph.D., head of R&D at Sanofi, told investors that the candidate could deliver data in 2025, launch in 2027 and generate blockbuster sales. The blockbuster prediction was built on the belief that existing patients would switch to efdoralprin alfa and new-to-treatment patients would choose the drug if it's approved.
Sanofi took a step toward realizing that vision Wednesday by reporting top-line data from a phase 2 trial. The study randomized people with alpha-1 antitrypsin deficiency (AATD) emphysema to take the AAT-Fc fusion protein efdoralprin alfa or CSL Behring’s Zemaira intravenously.
At Week 32, investigators recorded a statistically significant greater mean increase in functional AAT levels in people on the study drug than in those who received CSL’s standard-of-care plasma-derived therapy, according to Sanofi's Oct. 22 release.
As well as meeting its primary endpoint, the trial hit key secondary endpoints that looked at other details of AAT levels, Sanofi said.
Patients on Zemaira received the drug weekly. Efdoralprin alfa was given every three or four weeks, depending on which trial arm patients joined. Both efdoralprin alfa regimens beat Zemaira. Sanofi is yet to share data to compare the two efdoralprin alfa regimens, but it said the results support use every three or four weeks.
The available evidence suggests Sanofi’s drug candidate is better at ensuring patients have adequate AAT, a protein that protects the lungs, and can be given on a less-burdensome schedule. Sanofi plans to meet with regulators to discuss the next steps. Inhibrx designed the trial to generate data to support approval.
If approved, efdoralprin alfa will enter a market served by plasma-derived therapies from CSL, Grifols and Takeda.
Sanofi is part of a small pack of companies working on next-generation candidates. Grifols has a subcutaneous candidate in phase 1/2, while Takeda is taking an RNAi prospect through phase 3. In addition, Wave Life Sciences recently shared phase 1b/2a data on an RNA editing oligonucleotide in AATD.