Daiichi Sankyo's Q1 FY2026 earnings call (for the fiscal year ending March 2027), highlighted a revised readout timeline for Datroway in first-line non-small cell lung cancer (NSCLC), continued uncertainty over the regulatory strategy for raludotatug deruxtecan (R-DXd) in ovarian cancer, and plans to move a CD25-directed antibody-drug conjugate (ADC) into first-in-human testing. An October 10 US FDA action date for ifinatamab deruxtecan (I-DXd) in previously treated extensive-stage small cell lung cancer (SCLC) represents the company’s nearest potential product approval.

Revenue for the quarter rose 21.1% year-on-year to JPY 574.7 billion (USD 3.66 billion), driven by Enhertu (trastuzumab deruxtecan) and Datroway (datopotamab deruxtecan). Daiichi raised its full-year revenue forecast by JPY 60 billion to JPY 2.34 trillion, citing favorable currency movements, stronger-than-expected US Enhertu sales and growth in its European specialty business.

Key Strategic Signals

  • TROPION-Lung07 delay introduces uncertainty for Datroway's largest potential indication: Daiichi's R&D head Akihiro Inoguchi said top-line data from TROPION-Lung07, the Phase III study of Datroway plus pembrolizumab (Keytruda) with or without platinum chemotherapy in first-line NSCLC, will now be available in FY2027 rather than the second half of FY2026. Inoguchi attributed the delay to a schedule revision required after incorporating a biomarker as the primary endpoint. First-line NSCLC without actionable genomic alterations represents the broadest addressable population in Datroway's lung program. The revised timeline delays the potential regulatory path, although Daiichi Sankyo did not quantify the effect on any future filing
  • R-DXd filing strategy remains unresolved ahead of ESMO data: Inoguchi confirmed that Phase II dose-optimization data from REJOICE-Ovarian01 will be presented at ESMO, describing the readout as "key data" for determining the development path forward, with future filing strategy "under review". R-DXd is a CDH6-directed ADC being developed in a treatment setting where several therapies are already approved, making the eventual dose, efficacy and safety profile central to its regulatory strategy.
  • DS1025 enters Phase I as a new ADC modality targeting tumor immunosuppression: Inoguchi introduced DS1025, a novel antibody-drug conjugate (ADC) targeting CD25-positive regulatory T cells. The compound uses Daiichi Sankyo's DXd ADC platform but carries a cytotoxic payload described as "optimized for immuno-oncology" rather than the conventional DXd payload. Inoguchi said preclinical studies confirmed reductions in intratumoral regulatory T cells, activation of cytotoxic T cells, and antitumor efficacy, with a first-in-human trial in solid tumors planned for the first half of the fiscal year. Inoguchi declined to disclose payload details but said accumulated DXd ADC experience represents the key differentiating factor.
  • Datroway receives European approval for first-line triple-negative breast cancer (TNBC): Inoguchi confirmed that Datroway received EU approval for first-line metastatic or unresectable TNBC in patients not candidates for PD-1/PD-L1 inhibitor therapy, extending the US approval granted in May based on TROPION-Breast02 data. The study demonstrated a 5.3-month improvement in median progression-free survival (PFS) and a 5-month improvement in median overall survival (OS) versus chemotherapy. Regulatory submissions are under review in Japan and China.

Analyst Pressure Points

  • AVANZAR filing viability without mature OS data: JPMorgan's Seiji Wakao asked whether Datroway could support a regulatory submission from AVANZAR on PFS data alone, given that OS is unlikely to be mature at the time of the primary analysis. Inoguchi declined to endorse a PFS-only pathway, leaving open the question of whether a near-term filing is feasible.
  • TROPION-Lung08 biomarker endpoint design questioned: Bernstein's Miki Sogi challenged the decision to position TROP2 quantitative continuous scoring (TROP2-QCS) as a secondary rather than primary endpoint in TROPION-Lung08, the Phase III study comparing Datroway plus pembrolizumab versus pembrolizumab alone in PD-L1-high NSCLC. Inoguchi acknowledged the debate, saying that because pembrolizumab is standard of care in high PD-L1 expressors and the study is designed as an add-on comparison, demonstrating a positive result in the intent-to-treat population was considered the more important primary question.

Forward-Looking Catalysts

  • I-DXd PDUFA date in October for SCLC: Joseph Keller confirmed a PDUFA date in October for I-DXd in SCLC based on the IDeate-Lung01 trial, with Daiichi and Merck preparing for a potential launch, including education of key opinion leaders. Keller said physicians treating SCLC, a population with very high unmet need and few available options, have responded positively to early engagement. If approved, this would mark the first commercial launch of a Daiichi Sankyo-Merck co-promoted asset and the first approved indication for I-DXd.
  • DESTINY-Breast09 EU regulatory decision expected in H1 FY2026: Inoguchi said a European regulatory decision on the Phase III DESTINY-Breast09 trial, which evaluates Enhertu with or without pertuzumab versus taxane, trastuzumab and pertuzumab in first-line HER2-positive metastatic breast cancer, is expected in the first half of the current fiscal year. A positive decision would extend Enhertu's first-line breast cancer label in Europe and further consolidate its position against pertuzumab-based regimens.
  • ESMO data slate for HER3-DXd and R-DXd: Inoguchi said ESMO presentations will include first data from the melanoma cohort of the HERTHENA-PanTumor01 trial for HER3-DXd, an IDeate-Lung01 update, Phase II dose-optimization data from REJOICE-Ovarian01 for R-DXd, and early combination data from REJOICE-Ovarian02. The R-DXd readout will be closely watched given the unresolved filing strategy.

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