Vertex once again talks up a tiny trial with positive read-throughs, this time for a genetically driven approach to kidney disease

Vertex Pharma
(Vertex Pharma)

Vertex in October gained plaudits and criticism in equal measure when it released data showing a single patient in a trial of its diabetes cell therapy stopped needing insulin; this time around, it’s plugging another major breakthrough in a tiny test in kidney disease.

The oral, small-molecule drug, known as VX-147, is seeking to target for the first time the underlying cause of APOL1-mediated kidney disease, a form of chronic kidney disease caused by variants of the APOL1 gene that can lead to an aggressive form of the disease, and tends in the U.S. to affect African Americans.

In a tiny phase 2 using a urine-based biomarker as a primary endpoint, the company presented data from just 13 evaluable patients with APOL1-mediated focal segmental glomerulosclerosis (FSGS), a form of kidney scarring.

It showed that VX-147 on top of standard of care “achieved a statistically significant, substantial and clinically meaningful mean reduction” of 47.6% in the urine protein to creatinine ratio (UPCR) at 13 weeks, compared to baseline.

The UPCR can detect proteinuria, or protein in the urine, a standard biomarker for assessing kidney damage. Vertex said drug safety was clean, with the most common issues being headache, back pain and nausea.

The pharma said it wants to push on with VX-147 into pivotal trials in APOL1-mediated kidney disease, including FSGS, with plans to start this in the first quarter of next year, though more details were not shared.

RELATED: A single patient is producing insulin after treatment with Vertex's new diabetes cell therapy

“VX-147 is the first investigational treatment targeting the underlying cause of APOL1-mediated kidney disease,” said Carmen Bozic, M.D., executive vice president for global medicines development and medical affairs and chief medical officer at Vertex.

“These results demonstrate that inhibition of the APOL1 protein can substantially reduce proteinuria in patients with two APOL1 genetic variants, FSGS and significant proteinuria.

“We are working with urgency to advance this molecule into pivotal development with the goal of bringing this first-in-class therapy to the more than 100,000 patients in the U.S. and Europe living with APOL1-mediated kidney disease.”

Vertex's shares were up 5% premarket Wednesday morning.

Analysts at RBC Capital Markets were bullish on the news, saying the “magnitude of benefit looks highly impressive to us.”

It said Vertex had been aiming for a double-digit proteinuria reduction, and believes the effect size “appears to bring patients on average down to proteinuria levels that would generally qualify as partial remissions near the bottom end of the high-risk category in only a few months.”

Jefferies anaylsts, meanwhile, continued the love-in, saying it saw blockbuster sales in the drug's future for FSGS alone. It did note, however that Vertex didn't provide eGFR data, which is a lagging indicator for kidney function, and a "key question is whether FDA will approve a drug like this on a surrogate like proteinuria or will want eGFR to confirm the benefit." 

The firm however presumes "even just an eventual strong 'trend' would be good."