VRTX: Key Box Checked, As Otsuka's Sibe Affirms Class Renal Protective Effects- Positive Pove Readthroughs

Research evidence excerpt

VRTX: Key Box Checked, As Otsuka's Sibe Affirms Class Renal Protective Effects- Positive Pove Readthroughs

EQUITY RESEARCH QUICK TAKE

RBC Capital Markets, LLC

Brian Abrahams, M.D. (Head of Global

Healthcare Research)

Nevin Varghese, Ph.D. (Analyst)

Kevin Meli, Ph.D. (Senior Associate)

June 4, 2026

Vertex Pharmaceuticals Incorporated

Key Box Checked, As Otsuka's Sibe Affirms Class Renal Protective Effects- Positive Pove

Readthroughs

NASDAQ: VRTX | USD 441.74 | Outperform | Price Target USD 543.00

Sentiment: Positive

This afternoon at the ERA conference, Otsuka presented data from their marketed anti-APRIL Voyxact (sibeprenlimab) that

demonstrated that the drug, and we believe the class, demonstrates clear benefits in stabilizing renal function.

Otsuka noted that at 12 months, pts on sibe had their eGFR stabilize or even slightly improve vs. baseline (+0.7 mL/min/1.73m2),

whereas those on placebo showed steady declines starting 4 months out and ended with -4.8mL/min eGFR changes; annualized

slopes also demonstrated a clear benefit on kidney function (-3.0, vs. -7.6 for placebo).

We see this as having positive readthroughs for VRTX. While we believe there had been good evidence already suggesting that

proteinuria reductions seen with anti-APRIL+/-BAFF drugs like sibe and VRTX's pove would translate to kidney function/eGFR

benefits over longer time periods - pove showed eGFR stabilization and even improvement vs. baseline in the ph.I/II RUBY-3 study,

atacicept ph.IIb eGFR showed stabilization with longer-term follow-up, and the recently published telitacicept ph.III China data

demonstrated relative eGFR stabilization (-1%) vs. placebo decline (-8%) within 39 weeks - this is the first time we have seen this

shown clearly in a placebo-controlled study of a global population.