Justin Morrison

Justin Morrison asked about the larger standard error observed in povetacicept's RUBY-3 UPCR data compared to atacicept or siprolizumab, and Vertex's assumption for the placebo rate in the RAINIER interim analysis, given varying rates in competitor studies.

Answer

Reshma Kewalramani (CEO and President, Vertex Pharmaceuticals) deferred on the standard error comparison, noting that it is impacted by sample size and lab tests (24-hour urine vs. spot urine), and she had not reviewed the competitor data. For the RAINIER placebo rate, she reiterated a physician expert's estimate of 0-5% proteinuria improvement in the placebo group, which she believes is 'about right.'

Justin Morrison inquired about the larger standard error observed in povetacicept's (pove) RUBY-3 UPCR data compared to competitor studies, asking for potential causes of this variability. He also sought clarification on the company's assumption for the placebo rate in the RAINIER interim analysis, given differing placebo rates in competitor Phase III studies.

Answer

Reshma Kewalramani, CEO and President, reiterated the expectation of a 0-5% proteinuria improvement for the placebo group in RAINIER, noting that the placebo effect could vary. Regarding the standard error, she mentioned that it is influenced by factors such as sample size and the specific lab tests used (e.g., 24-hour urine versus spot urine), but she had not reviewed the competitor data in question.