VRTX Stock Gains on Upbeat Interim Data From Kidney Disease Drug Study

Vertex Pharmaceuticals VRTX announced positive data from an interim analysis of the ongoing phase III RAINER study, which evaluated its investigational drug povetacicept for IgA nephropathy (IgAN), a rare progressive kidney disease.

At the interim analysis, the RAINER study achieved its primary endpoint — treatment with the drug for 36 weeks achieved a 52% reduction from baseline in proteinuria (protein in the urine). High levels of protein in urine tend to indicate that the kidneys are not filtering properly. Treatment with the drug outperformed placebo by 49.8%.

Treatment with the drug was safe and well-tolerated in study participants. The RAINER study achieved all its secondary endpoints.

Vertex had previously started a rolling submission with the FDA seeking accelerated approval for povetacicept in the IgAN indication in fourth-quarter 2025. With the encouraging interim data from the RAINER study, the company expects to complete its submission by the end of this month. VRTX had previously announced in November that it would use a priority review voucher (PRV) to expedite the review of this FDA filing. The PRV will reduce the review period by four months.

VRTX Stock’s Performance

Shares of Vertex Pharmaceuticals were up nearly 5% in after-market trading yesterday, following the announcement. Several investors were impressed with the better-than-expected interim results, which exceeded their initial expectations.

Year to date, shares of Vertex have gained about 2% compared with the industry’s 6% growth.

More on VRTX’s Povetacicept

The drug is designed to target two proteins, namely BAFF and APRIL, which are key regulators of B-cell activity for multiple serious autoimmune diseases. The drug was added to Vertex’s pipeline following the acquisition of Alpine Immune Sciences in 2024.

Final analysis of data from the RAINER study will occur at two years of treatment. The primary endpoint at the final analysis will be the total estimated glomerular filtration rate (eGFR) slope. This study completed full enrolment in November 2025.

Apart from IgAN, povetacicept is being evaluated for other indications. Vertex is enrolling patients in a pivotal phase II/III study of povetacicept for a second potential renal indication, primary membranous nephropathy (pMN). The company plans to start a mid-stage study on the drug for treating generalized myasthenia gravis (gMG) in the first half of 2026.

Other Players in the IgAN Space

If approved, povetacicept will likely compete with the likes of Calliditas Therapeutics’ Tarpeyo, Novartis’ NVS Fabhalta and Travere Therapeutics’ TVTX Filspari.

Both Calliditas’ Tarpeyo and Travere’s Filspari are approved for a similar indication — to slow the decline in kidney function in adults with primary IgAN who are at risk of disease progression.

Novartis’ Fabhalta is approved under the accelerated pathway for reducing proteinuria in adults with primary IgAN at risk of rapid disease progression. The NVS drug is also approved for complement 3 glomerulopathy (C3G) and paroxysmal nocturnal hemoglobinuria (PNH) indications.

Vertex Pharmaceuticals Incorporated Price

 

Vertex Pharmaceuticals Incorporated price | Vertex Pharmaceuticals Incorporated Quote

VRTX’s Zacks Rank

Vertex currently carries a Zacks Rank #3 (Hold). You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

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This article originally published on Zacks Investment Research (zacks.com).

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