米国時間5月29日より、米国臨床腫瘍学会（American Society of Clinical Oncology: ASCO）が開催されています。弊社サイニクス株式会社のパートナーであるOracle Life Sciencesのオンコロジースペシャリストおよび弊社 オンコロジーマーケットアセスメントチームが注目しているASCO 2026トピックをお届けします。なお、弊社サイニクスのメンバーも現地シカゴよりASCOに参加しております。

また、今年もOracle Life Sciencesと共催で『最新のオンコロジー学会からみる薬剤開発と治療展望 – 第21回 Evolving Trends in Oncology』セミナーを9月上旬に、オンラインで開催する予定です。ASCOや、欧州臨床腫瘍学会（European Society for Medical Oncology：ESMO）、米国癌学会（American Association for Cancer Research: AACR）など最新学会の発表内容を踏まえ、今日のアンメットメディカルニーズ(UMNs)、臨床的意義と市場性の観点から注目される開発、治療展望について、最新の注目キーワードを切り口にオンコロジースペシャリストがインサイトを交えて解説する予定です。

『最新のオンコロジー学会からみる薬剤開発と治療展望 – 第21回 Evolving Trends in Oncology』

（9月上旬・オンラインセミナー）

正式な日程ほか詳細は後日、弊社サイニクスHPでご案内いたします。

ASCO 2026の注目トピック

Direct RAS inhibition and targeted approaches in earlier disease settings

　（詳細はこちら）

・Pan-RAS opens a Pan-dara’s box / Abstract LBA5 (Sun 5/31)
Revolution Medicine’s announcement that daraxonrasib in the RASolute 302 study nearly doubled overall survival (OS) in 2nd line pancreatic cancer from 6.7 to 13.2 months, represents a watershed moment for this notoriously hard-to-treat disease, but also for the broader future of pan-RAS inhibition across solid tumors. Importantly, the survival signal appears to come with a manageable tolerability profile, a critical factor in 2nd line, where frailty, cumulative toxicity, and treatment burden impact use. The data suggest that targeting RAS biology more comprehensively may finally be translating into clinically meaningful benefit in tumors historically resistant to precision medicine approaches. The results raise an increasingly important question: are we approaching a tipping point where RAS can be targeted beyond single G12 point mutations?

・Charting the early RET landscape / Abstract LBA3 (Sun 5/31)
Building on the success of RET inhibition in the metastatic setting, LIBRETTO-432 demonstrated a “substantial” event-free survival benefit for selpercatinib as adjuvant therapy in stages IA–IIIA RET+ NSCLC. The study represents another important step in the migration of precision oncology into earlier-stage, potentially curative disease settings. The key debate now is not whether adjuvant RET inhibition is active, but whether the magnitude and durability of benefit will be sufficient to place it alongside landmark adjuvant targeted therapy studies such as ADAURA (EGFR mutant) and ALINA (ALK-positive), which fundamentally reshaped expectations for biomarker-driven therapy in resected lung cancer.

・PARP(s) for the course / Abstract LBA5007 (Sat 5/30)
Back in March 2026, Pfizer announced positive rPFS data for talozaparib + enzalutamide in metastatic castrate-sensitive prostate cancer with HRR gene mutations based on the TALAPRO-3 study. The movement of the PARP class into earlier, less refractory stage disease holds promise as the study may help clarify how aggressively clinicians should integrate genomic testing and combination precision therapy into frontline mCSPC management. If positive, TALAPRO-3 could further solidify PARPi therapy as a foundational component of prostate cancer treatment, however there remains significant disagreement on whether rPFS as a surrogate endpoint is predictive of a benefit in OS, although the sponsor reports a trend for OS benefit (a key secondary endpoint) has been observed and will continue to be followed.

Next-gen IO gets bispecific

（詳細はこちら）

・Can Ivonescimab bring HARMONi to SqNSCLC? / Abstract LBA4 (Sun 5/31)
HARMONi-06 will test whether ivonescimab, a PD-1/VEGF bispecific antibody, plus chemo can challenge tislelizumab + chemo in 1st line squamous NSCLC. Following strong prior efficacy signals from dual immune and angiogenesis blockade, the study may help determine whether IO bispecific antibodies can deliver superior outcomes without substantially increasing toxicity burden. This updated data will focus on the OS readout following positive PFS data presented at ESMO 2025, and carries particular importance given the high bar set with other regimens and the mixed survival results presented in other recent trials. In addition, as a China-only study population, concerns remain about the applicability of these findings to Western markets; the data will need to be interpreted with the global HARMONi-03 study which compares against pembrolizumab + chemo, the global standard of care.

・Double-Barreled ADCs Arrive in Style / Abstract LBA1003 (Tue 6/2)
Izalontamab brengitecan (EGFR x HER3, topo-1 inhibitor payload) is the first bispecific ADC to report positive data in a pivotal study (esophageal cancer), and we will also get a first look at pivotal data in TNBC from the multi-center PANKU-Breast02 clinical study in China. Iza-Bren is leading the way to a broader shift towards sophisticated antibody engineering strategies to improve targeting precision, payload delivery, and therapeutic index. Unlike earlier-generation ADCs, these next-wave constructs aim to simultaneously engage multiple tumor-associated pathways while maintaining manageable safety profiles. These results may offer an important glimpse into whether bispecific ADCs can meaningfully differentiate themselves within the increasingly crowded ADC space, with recent success of TROP2 ADCs such as Trodelvy and Datroway.

・Double-Barreled ADCs Arrive in Style / Ab・Dual Biomarker Play in Gastric Cancer / Abstract 4036
Q-1802 is a first-in-class humanized bispecific antibody that targets both CLDN18.2 and PD-L1. QureBio is presenting Phase 1/2 data for Q-1802 plus XELOX in treatment-naive, CLDN18.2-positive, HER2-negative advanced gastric/GEJ cancer. The study enrolled 62 eligible patients, reported no dose-limiting toxicities, did not reach MTD, and showed an ORR of 70.0%, DCR of 98.3%, and median PFS of 11.3 months in efficacy-evaluable patients. Even more promising, patients with co-occurring CLDN18.2 positivity and PD-L1 expression had higher response rates. This data makes a strong case for initiation of a Phase 3 trial, but it remains to be seen how common the co-occurrence of CLDN18.2 and PD-L1 positivity is in gastric cancers.