Zymeworks Inc. Q3 FY2025 earnings call

• Clinical programs: Initial clinical data from ZW191 Phase I trial presented at ENA conference, first patient dosed in ZW251 Phase I trial, preclinical data of ZW1528 presented at ERS Congress. - Partnered programs: Jazz and J&J provided encouraging data at ESMO, Jazz announced ITT population for HERIZON-GEA-01 trial, J&J presented translational findings on pasritamig. - Share repurchases: Completed $22.7 million of $30 million authorized share repurchase program. - Program discontinuation: Discontinued development of ZW171, learning from the experience to prioritize programs with clearer path to patient benefit.

Total revenue for the third quarter of 2025 was $27.6 million, compared to $16 million in the third quarter of 2024. Operating expenses for the 3 months ended September 30, 2025, were $49.7 million, down 1% from $50.2 million in the same period of 2024. Net loss was $19.6 million in Q3 2025, compared to a net loss of $29.9 million in Q3 2024. As of September 30, 2025, cash, cash equivalents, and marketable securities totaled $299.4 million, a decrease from $324.2 million as of December 31, 2024. Revenue contribution came from a $25 million development milestone from J&J and $1 million in royalties from Jazz and BeOne Medicines.

• Expect existing cash resources combined with anticipated regulatory milestones to fund planned operations through the second half of 2027, covering multiple pipeline catalyst events. - Maintain optionality for stock repurchases to allocate capital at attractive prices to boost TSR.

• Usual risks associated with clinical development, such as uncertainties in trial outcomes and regulatory approvals. - Market uncertainties and competition in the biopharmaceutical industry.

Q: Thoughts on HERIZON-GEA-01 trial ITT population update and what drove the change?

A: Aligned with Jazz's regulatory strategy, no additional insights beyond what Jazz shared.

Q: Thoughts on GPC3 asset ZW251 and comparison to B1's bispecific GPC3 4-1BB?

A: Intrigued by ZW191 data, ZW251 study recruiting, focusing on tolerability and efficacy similar to ZW191.

Q: Starting dose levels of ZW251 relative to ZW191?

A: Schema similar to ZW191, more confident in starting dose now but not disclosed yet.

Q: Confidence in GPC3 activity post-first-line HCC and biomarker needs?

A: Expression level of GPC3 not modulated by IL treatment, will collect biomarker data as clinical development progresses.

Q: Durability of ZW191 responses and combination potential?

A: Encouraging response rates, wide therapeutic index, potential for combination in earlier lines with favorable safety profile.

Q: Correlation between H-score and PS2+ scoring for ZW191?

A: High correlation, ZW191 shows activity across spectrum including lower expressing patients.

Q: Differentiation of DLL3 CD3, CD28 trispecific and use of future milestones?

A: Aim for more patients responding and longer responses, expect authorized stock repurchase program to continue for capital allocation.