By Fineline Cube Daiichi Sankyo (TYO: 4568) announced it has discontinued internal development of DS-9606, a Claudin 6 (CLDN6)-targeting antibody-drug conjugate (ADC), and delayed topline results for the AVANZAR Phase III trial evaluating datopotamab deruxtecan (Dato-DXd) in first-line NSCLC. The setbacks reflect portfolio prioritization and slower-than-expected clinical event rates.
DS-9606 Discontinuation & Partnership Outlook
| Item | Detail |
|---|---|
| Drug | DS-9606 (CLDN6-targeting ADC) |
| Payload | Modified pyrrolobenzodiazepine (mPBD) |
| Decision | Internal development discontinued |
| Rationale | Commercial and portfolio perspective (not platform-related) |
| Opportunity | Potential partner development remains viable |
| Preclinical Data | Showed “good results” in germ cell tumors |
Dato-DXd Pipeline Setbacks
| Trial | Indication | Status | Impact |
|---|---|---|---|
| Initial FDA Application | 2L non-squamous NSCLC | Withdrawn 2024 | Disappointing OS results |
| AVANZAR (Phase III) | 1L NSCLC with Imfinzi | Delayed to H2 2026 vs. H1 2025 (original) | Slower clinical event rate |
| TROPION-Lung12 | Adjuvant stage I NSCLC with rilvegostomig | Enrollment halted | Study operation complexity |
Market Impact & Strategic Implications
- ADC Portfolio: Discontinuation of DS-9606 narrows Daiichi’s ADC pipeline but preserves mPBD platform for future candidates
- Dato-DXd Revenue Risk: Delays jeopardize anticipated $2–3 billion peak sales potential in NSCLC; competitive pressure from Trodelvy and Enhertu intensifies
- Partner Opportunity: DS-9606’s germ cell tumor data may attract biotech partners for out‑licensing
- Platform Validation: Management stressed mPBD platform remains viable; decision reflects strategic focus on higher‑value assets
- Investor Sentiment: Shares fell ~6% : on Tokyo exchange as investors reassess ADC pipeline prospects
Forward‑Looking Statements
This brief contains forward‑looking statements regarding partnership opportunities, clinical timelines, and commercial prospects for Daiichi Sankyo’s ADC pipeline. Actual results may differ due to competitive dynamics, regulatory feedback, and clinical trial outcomes.-Fineline Info & Tech