Updating Estimates Following Kissei’s Tavneos Safety Update

Research evidence excerpt

Updating Estimates Following Kissei’s Tavneos Safety Update

Japan | Pharmaceuticals

Kissei Pharmaceutical EquityMayResearch22, 2026

TARGET | ESTIMATE CHANGEUpdating Estimates Following Kissei’s

RATING BUYTavneos Safety Update

PRICE ¥3,970^

Reflecting Kissei’s safety notice on Tavneos last Friday and Rapid Safety

Communication on May 15, we cut our Tavneos sales forecast to ¥5.4bn PRICE TARGET | % TO PT ¥4,800 (¥5,400) | +21%

from ¥11.8bn. Meanwhile, following matsupexole’s achievement of its 52W HIGH-LOW ¥5,040 - ¥3,500

primary endpoint, we raise the probability of success and incorporate the FLOAT (%) | ADV MM (USD) 63.0% | 2.95

potential for out-licensing into our estimates. As a result, we derive a new MARKET CAP ¥165.0B | $1.0B

target price of ¥4,800 and reiterate our Buy rating. TICKER 4547 JP ^Prior trading day's closing price unless otherwise

noted.

Kissei updates Tavneos safety information. Kissei issued a release on May 15 regarding

the appropriate use of Tavneos, urging healthcare professionals to refrain from initiating

FY (Mar) CHANGE TO JEFe JEF vs CONS

treatment in new patients. Following this, domestic media widely highlighted safety concerns,

2026 2027 2026 2027

emphasizing 20 reported deaths. Although hepatotoxicity risks had already been recognized

among physicians, the release likely heightened anxiety among a broader group of doctors REV -6% NM -4% +4%

and patients. Subsequently, Rapid Safety Communication (Blue Letter) released on May 21 EPS -46% -6% -54% +10%

requires more frequent liver function monitoring and explicit discontinuation criteria, while can

be interpreted as allowing use in new patients under appropriate management. 2026 (¥) Q1 Q2 Q3 Q4 FY3

EPS 50.18 30.78 59.80 2.39 143.14

Cut Tavneos sales estimates.