Pharvaris Reports 83% Reduction in Hereditary Angioedema Attacks Versus Placebo in Pivotal CHAPTER-3 Study

by Carter Whitfield · September 8, 2026

Equities Reporter, The SmallCap Signal

Pharvaris N.V. (Nasdaq: PHVS) said Tuesday that its pivotal CHAPTER-3 study of deucrictibant extended-release met its primary endpoint, cutting the mean monthly rate of hereditary angioedema attacks by 83 percent versus placebo with a p-value below 0.0001.

According to the company's Sept. 8 release, CHAPTER-3 was a global, double-blind, placebo-controlled Phase 3 trial that randomized 85 participants two-to-one to a 40 mg once-daily oral tablet of deucrictibant XR or placebo, across 21 countries, with a 24-week treatment period. The population spanned adolescents and adults with all three recognized forms of the disease: HAE type 1, HAE type 2, and HAE with normal C1 inhibitor.

In the subgroup of 80 participants with type 1 or type 2 disease — the forms driven by C1-inhibitor deficiency or dysfunction — the company reported an 87 percent reduction in mean monthly attack rate versus placebo.

Pharvaris said all secondary efficacy endpoints were met with statistical significance, assessed sequentially under a multiplicity-control procedure. That detail is worth pausing on. A hierarchical testing sequence means each endpoint is only formally tested if the one above it succeeds, which prevents a company from claiming a scattered handful of wins pulled from a long list. Clearing the full ranked sequence is a meaningfully stronger result than reporting nominal significance on individual measures.

On the shape of the effect, the company said protection began within the first week of dosing and was sustained through week 24, and reported what it described as robust increases in the proportion of participants who were attack-free. Pharvaris did not disclose the specific attack-free percentages in the topline release.

The safety description was uneventful in the way developers hope for. Pharvaris said the drug was well tolerated, that most treatment-emergent adverse events were mild or moderate, that there were no treatment-related serious adverse events, and that one participant in each arm discontinued because of an adverse event. A one-for-one discontinuation split between drug and placebo is a favorable balance in a 24-week study, though the absolute numbers are small.

Marc Riedl of the University of California, San Diego, who is quoted in the company's release, said the CHAPTER-3 results further confirm the value of targeting the bradykinin B2 receptor to prevent attacks across all three types of the disease.

Marc A. Riedl, the study's principal investigator, said in the company's release that people living with HAE are seeking novel treatment options offering improved disease control.

Pharvaris is headquartered in Zug, Switzerland, and organized as a Dutch N.V. while trading on Nasdaq — a structure worth noting in a company otherwise covered as a U.S.-listed biotech.

Pharvaris is domiciled in Zug, Switzerland, and organized as a Dutch N.V., trading on Nasdaq as a foreign private issuer. That structure carries practical consequences for U.S. shareholders — reduced periodic-reporting cadence relative to domestic filers among them — that are easy to overlook in a company otherwise covered as a U.S.-listed biotech.

The market response Tuesday was positive but should not be described in closing terms. Investrade's mid-morning summary, stamped 14:32:49 UTC — 10:32 a.m. ET, with U.S. trading still open — listed Pharvaris among the session's gainers at roughly 14 percent higher, citing the trial's endpoint results. That is an intraday level during a live session, not a close.

The strategic question the topline does not answer is competitive rather than clinical. An 83 percent placebo-adjusted reduction is a strong number in isolation, but HAE prophylaxis is a field where existing approved therapies already post high attack-rate reductions, and the cross-trial comparisons that inevitably follow are not valid: different populations, different baseline attack rates, different eras of background care. The commercially decisive variables are more likely to be the oral route, the tolerability profile, and pricing — none of which are settled by a topline release.

Investors will get the fuller picture when Pharvaris presents detailed CHAPTER-3 data at a medical meeting or in a peer-reviewed publication. Until then, the summary statistics above are what the company has put on the record.

Risk note: Pharvaris is a clinical-stage company with no approved products. Topline results are unaudited company summaries that can shift when full datasets are presented, and regulatory submission and approval remain uncertain. This article is not investment advice.