Lyell Immunopharma Completes LYL273 Transfer, Updates Phase 1/2 Timeline

What Happened
Lyell Immunopharma, Inc. (LYEL) filed an 8‑K on September 10, 2026, announcing completion of the technology transfer for LYL273 to its LyFE Manufacturing Facility™ in Bothell, Washington and providing an updated timeline for the Phase 1/2 clinical trial of LYL273 in metastatic colorectal cancer. LYL273 is Lyell’s next‑generation guanylyl cyclase C (GCC)‑targeted CAR T‑cell product candidate for relapsed/refractory metastatic colorectal cancer and other GCC‑expressing cancers. The company attached the related press release as Exhibit 99.1.

Key Details

• Date filed: September 10, 2026 (Form 8‑K, Item 8.01).
• Manufacturing: Technology transfer of LYL273 to Lyell’s LyFE Manufacturing Facility™ in Bothell is complete.
• Clinical program: Company provided an updated timeline for its Phase 1/2 trial in metastatic colorectal cancer (details are in the press release filed as Exhibit 99.1).
• Product: LYL273 is a next‑generation GCC‑targeted CAR T‑cell candidate for relapsed/refractory metastatic colorectal cancer and other GCC‑expressing tumors.

Why It Matters
The completion of the manufacturing technology transfer is a key operational step toward internal production and potential scale‑up of LYL273, which can accelerate clinical supply and trial progress. For investors, updates to the Phase 1/2 timeline affect expectations for upcoming clinical milestones and potential value‑driving data readouts. The 8‑K does not provide specific milestone dates or new clinical results—investors should review the referenced press release (Exhibit 99.1) and company communications for detailed timing.