ASCO 2026 takeaways: encouraging first mPFS readout for 707 in 1L PD-L1+ NSCLC

ASCO2026takeaways:encouraging first mPFSreadout for 707 in 1L PD-L1+ NSCLC Target PriceHK$34.87Up/Downside81.4%Current PriceHK$19.23 ASCO2026 disclosed two abstracts for 707/ PF’4404in1LPD-L1+NSCLC monoand1L EC in combination with chemo. On a cross-trialbasis, 707 demonstratedcompetitivemPFS versusivonescimabin 1L NSCLC, with particular strength inthe NSQ subgroup.707also showed encouraging ORRsin1L EC, especially inpMMR patients.Wecontinue to expect partner Pfizer’s globaltrialexecution andadditional clinical readoutsto bethe main drivers ofstock priceupside for 3SBio. China Healthcare Jill WU, CFA(852) 3900 0842jillwu@cmbi.com.hk FirstmPFS readoutsolidified 707 as a competitive candidate in 1L PD-L1+ NSCLC.In the ChinaPh2study in1L PD-L1+ NSCLC, 707 mono (10mg/kg Q3W) achievedmPFS of 12.4 months,slightlyahead ofivonescimab’s11.14 monthsreported inHARMONi-2on a cross-trial basis.By subgroup,mPFS was12.4 monthsin bothPD-L1highandNSQpatients (vs. ~11 monthsfor ivonescimab). The PFS benefits of 707 and ivonescimab in PD-L1 lowsubgroup are largely at the same level (seeFigure1).In our view, the datasupport 707 as a highly competitive candidate in PD-(L)1/VEGF class.Onsafety,Gr3+ TRAEsratewas42.2% across 83 patients in all dose subgroups,withGr3+irAEs and VEGF-related AEs were 8.4% and 18.1%, respectively.Wenote that this safety profile included higher-dose subgroups, including 20mg/kg and 30 mg/kg Q3W, limiting direct cross-trial comparison. In the 10 mgcohort previously presented at ASCO 2025, Gr3+ TRAEsratewas23.5%,versus 29.4% for ivonescimabinHARMONi-2, suggesting a favorable safetyprofile at the intended dose. Cathy WANG(852) 3916 1729cathywang@cmbi.com.hk Stock Data Encouragingpreliminary1L EC data.Thepreliminarydata for 707 + chemoin 1L ECwereencouraging,especiallyin pMMRpatients,who account for~70%of EC and typically derive less benefit from immunotherapy. In pMMREC, the5mg and 10mgsubgroupsof 707achievedcORRs of 83.3% and81.8%, respectively, versus72.3%forthe current SOC ofpembrolizumab +chemoon a cross-trial basis.Gr3+TRAEsratewas68.8% across32patientsinbothdose subgroups which wasbroadly manageable. Notably, Pfizer hasalready registered aglobalPh3studyin1LpMMREC. Pfizer’s strong clinical executionand further readoutsshould continuetobe a key driver for 3Sbio.Pfizer hasregisteredelevenglobal studiesfor707, includingthree globalPh3studiesacrossfour1Lindications.Notably,Pfizer also plans to initiate aglobalPh3trialfor707+PADCEV (Nectin-4 ADC)in 1L UCin 2026E.Looking ahead, we expectadditional China Ph2 readoutsof 707+chemo in1L NSCLCandmCRC in 2H26E, which could serve as near-term catalysts. Source: FactSet Maintain BUY. We view the ASCO2026 data for 707 as encouraging andreiterate our positiveviewon its global potential.We maintain our target priceunchangedatHK$34.87basedon a 10-year DCF model(WACC: 10.11%,terminal growth rate: 2.0%).Earnings Summary Disclosures& Disclaimers Analyst CertificationThe research analyst who is primary responsible for the content of this research report, in whole or in part, certifies thatwith respect to the securities or issuer that the analyst coveredin this report: (1) all of the views expressed accurately reflect his or her personal views about the subject securities or issuer; and (2)no part of his or her compensation was, is, or will be, directly or indirectly, related to the specific views expressed by that analyst in this report.Besides, the analyst confirms that neither the analyst nor his/her associates (as defined in the code of conduct issued by The Hong Kong Securities and Futures Commission) (1) have dealt in or traded in the stock(s)covered in this research report within 30 calendar days prior to the date of issue of this report; (2) willdeal in or trade in the stock(s) covered in this research report 3 business days after the date of issue of this report; (3)serve as an officer ofany of the HongKong listed companies covered in this report; and (4) have any financial interests in the Hong Kong listed companies coveredin this report.CMBIGM Ratings BUY : Stock with potential return of over 15% over next 12 months:Stock with potential return of +15% to-10% over next 12 months: Stock with potential loss of over 10% over next 12 months: Stock is not rated byCMBIGM HOLDSELLNOT RATED OUTPERFORM:Industry expected to outperform the relevant broadmarket benchmark over next 12 monthsMARKET-PERFORM:Industry expected to perform in-line with the relevant broad market benchmark over next 12 monthsUNDERPERFORM:Industry expected to underperform the relevant broad market benchmark over next 12 monthsCMB InternationalGlobal MarketsLimited Address: 45/F, Champion Tower, 3 Garden Road, Hong Kong, Tel: (852) 3900 0888 Fax: (852) 3900 0800CMB InternationalGlobal MarketsLimited (“CMBIGM”) is a wholly owned subsidiaryof CMB International Capital Corporation Limited (a wholly ownedsubsidiary of China Merchants Bank) Important DisclosuresThere are risks involv