EXEL/MRK: SubQ Keytruda confirmed as STELLAR-316's ICI

Research evidence excerpt

EXEL/MRK: SubQ Keytruda confirmed as STELLAR-316's ICI

USA | Biotechnology EquityMayResearch19, 2026

KEY STOCKS FEATURED INCLUDE:EXEL/MRK: SubQ Keytruda confirmed as

TICKER RATING PRICE TARGETSTELLAR-316's ICI

EXEL BUY $62.00

EXEL announced a clin dvt collab w/ MRK today to supply SubQ Keytruda for MRK BUY $138.00

STELLAR-316 trial in post-adj ctDNA+ CRC pts. To us, this looks +'ve, as: a) it

further validates that MRK sees Zanza as a competitive choice for combo tx

in future, b) we think Street could be underestimating strategic value re: Natera

KEY CHANGES INCLUDE:

collab to identify ctDNA +'ve CRC pts, who have >60% higher relapse rate vs -'ve,

and c) maintenance pop could be surprising upside (~20% relapse in ~6mo) TICKER RATING PRICE TARGET

EXEL BUY $62.00 ($52.00)

Bottom Line: EXEL announced today that Co entered into a clinical development collaboration

with MRK to supply Keytruda QLEX subQ for EXEL's STELLAR-316 trial (Co intends to initiate

study mid-26). Keep in mind EXEL prev. disclosed STELLAR-316 is zanza+ICI in pts w/ resected

stage II/III CRC who have completed definitive therapy and tested positive for molecular residual

disease (MRD), but do not have radiographic evidence of disease. The primary endpoint is DFS w/

secondary, including circulating tumor DNA clearance. To us, this collaboration looks positive,

since:

#1) It further validates that MRK sees Zanza as a competitive choice for combo tx going forward

- remember EXEL prev. announced two MRK RCC trial collaborations: i) LITESPARK-033 zanza

+belzu in prev-tx adj pembro pts, which we view as a '2 for 1' since it's not only in 1L post-adjuvant,

but this population is effectively where the RCC market is heading, since pembro monotherapy