Empaveli reduced proteinuria by 68% versus placebo in glomerulopathy and glomerulonephritis, an effect that was sustained through one year of follow-up.
Apellis and Sobi’s complement regulator Empaveli—sold under the brand name Aspaveli in Europe—sustained the reduction of proteinuria in patients with C3 glomerulopathy and primary immune complex membranoproliferative glomerulonephritis through one year in a Phase III trial, potentially bolstering the drug’s case ahead of a July PDUFA date.
Analysts at William Blair said in a Monday note that the new data continue to support Empaveli’s “game-changing profile” in the two rare kidney diseases.
"[Empaveli] has best-in-class efficacy that should drive significant adoption in this underserved population over time,” the analysts wrote.
In the Phase III VALIANT trial, Empaveli lowered proteinuria by 68% versus placebo at 28 weeks, an effect the partners claimed was statistically significant. Empaveli, they added, was able to sustain this benefit through one year of follow-up. Kidney function, as measured by estimated glomerular filtration rate, also stabilized in patients treated with Empaveli.
The development partners presented the data during a late-breaking session at the European Renal Association Congress.
VALIANT enrolled nearly 125 patients 12 years and up who had been diagnosed with C3 glomerulopathy (C3G) and primary immune complex membranoproliferative glomerulonephritis (IC-MPGN)—both rare kidney diseases characterized by inflammation in the organ linked to excessive deposits of the C3 complement protein. Both diseases can ultimately lead to kidney failure in half of patients within 10 years of diagnosis.
Designed to be injected under the skin, Empaveli inhibits the immune system’s complement cascade, a part of the body’s immune system. This mechanism of action won the drug an FDA approval in May 2021 in paroxysmal nocturnal hemoglobinuria. European approval came a few months later.
Apellis, which partnered with Sobi in October 2020 to bring the drug to ex-U.S. markets, has since worked to expand Empaveli’s label. In April, the biotech announced that the FDA accepted its application to use Empaveli in C3G and IC-MPGN and granted the drug Priority Review. A verdict is expected by July 28.
Elsewhere in the kidney disease space, Otsuka also revealed promising data on Friday for its antibody therapy sibeprenlimab. Late-stage results in patients with immunoglobulin A nephropathy showed that sibeprenlimab could reduce proteinuria by 51.2% versus placebo—an effect that Guggenheim Partners called “impressive” in a Friday note. Sibeprenlimab, they continued, showed “the strongest numerical result reported to date in IgAN Phase 3 trials.”
Otsuka has yet to detail out its regulatory plans for sibeprenlimab, though the company on Friday emphasized that “proteinuria reduction is a recognized surrogate marker” and “has been used as an endpoint in IgAN clinical trials to support accelerated regulatory approvals.”
