Sensei Biotherapeutics Reports New Clinical Results Highlighting Durable Progression Free Survival Data for Solnerstotug in PD-(L)1 Resistant Tumors at the ESMO Congress 2025
Sensei Biotherapeutics (Nasdaq: SNSE) reported Phase 1/2 dose-expansion results for solnerstotug at ESMO 2025 showing dose-dependent activity and tolerability in PD-(L)1 resistant “hot” tumors.
Key data: 6-month PFS 50% at 15 mg/kg in PD-(L)1 resistant patients versus overall 6-month PFS of 37% across prior PD-(L)1 progressors; six clinical responses occurred at 15 mg/kg including one durable complete response (MCC, 54+ weeks). Safety: six Grade 1 CRS events (all at 15 mg/kg) and no new safety signals (Phase 1 n=98, dose expansion n=64).
Sensei plans Phase 2 trials in 2L NSCLC and PD-(L)1 resistant MCC in 2026, subject to FDA feedback and financing. Investor webcast Oct 20, 2025 at 8:00 AM ET.
Sensei Biotherapeutics (Nasdaq: SNSE) ha riportato risultati della Fase 1/2 di espansione della dose per solnerstotug all'ESMO 2025, mostrando attività e tollerabilità dipendenti dalla dose in tumori “caldi” resistenti a PD-(L)1.
Dati chiave: PFS a 6 mesi 50% a 15 mg/kg nei pazienti resistenti a PD-(L)1 rispetto al PFS globale a 6 mesi di 37% tra i progressori precedenti a PD-(L)1; sei risposte cliniche si sono verificate a 15 mg/kg inclusa una risposta completa duratura (MCC, 54+ settimane). Sicurezza: sei eventi CRS di grado 1 (tutti a 15 mg/kg) e nessun nuovo segnale di sicurezza (Fase 1 n=98, espansione dose n=64).
Sensei prevede studi di fase 2 in NSCLC 2L e MCC resistente a PD-(L)1 nel 2026, subordinati al feedback della FDA e al finanziamento. Webcast per gli investitori il 20 ottobre 2025 alle 8:00 AM ET.
Sensei Biotherapeutics (Nasdaq: SNSE) informó resultados de la fase 1/2 de expansión de dosis para solnerstotug en la ESMO 2025, mostrando actividad y tolerabilidad dependientes de la dosis en tumores “calientes” resistentes a PD-(L)1.
Datos clave: PFS a 6 meses 50% a 15 mg/kg en pacientes resistentes a PD-(L)1 frente a un PFS de 6 meses del 37% entre progresores previos a PD-(L)1; seis respuestas clínicas se produjeron a 15 mg/kg, incluida una respuesta completa durable (MCC, 54+ semanas). Seguridad: seis eventos CRS grado 1 (todos a 15 mg/kg) y no se observaron nuevos signos de seguridad (Fase 1 n=98, n=64 en expansión de dosis).
Sensei planea ensayos de fase 2 en NSCLC 2L y MCC resistente a PD-(L)1 en 2026, sujeto a comentarios de la FDA y financiamiento. Transmisión para inversores el 20 de octubre de 2025 a las 8:00 AM ET.
Sensei Biotherapeutics (Nasdaq: SNSE)는 ESMO 2025에서 solnerstotug에 대한 1/2상 용량 확장 결과를 발표했습니다. PD-(L)1에 내성인 ‘핫(hot) tumor’에서 용량 의존적 활력과 내약성을 보였습니다.
주요 데이터: 6개월 PFS 50%가 15 mg/kg에서 PD-(L)1 내성 환자에서, 전체 6개월 PFS 37%를 보인 이전 PD-(L)1 진행자들 사이에서; 15 mg/kg에서 6건의 임상 반응이 관찰되었고 그 중 하나는 지속적 완전 반응(MCC, 54주 이상)입니다. 안전성: 15 mg/kg에서만 나타난 6건의 등급 1 CRS 사건, 새로운 안전성 신호는 없음(1상 n=98, 용량 확장 n=64).
Sensei는 2026년에 2L NSCLC 및 PD-(L)1 내성 MCC에서 2상 시험을 계획하고 있으며 FDA 피드백 및 자금 조달에 따라 달라질 예정입니다. 투자자 웨비스트는 2025년 10월 20일 동부표준시 8:00에 진행됩니다.
Sensei Biotherapeutics (Nasdaq: SNSE) a présenté les résultats de la phase 1/2 d’expansion de dose pour solnerstotug à l’ESMO 2025, montrant une activité et une tolérance dépendantes de la dose dans des tumeurs “chaudes” résistantes à PD-(L)1.
Données clés : PFS à 6 mois 50% à 15 mg/kg chez les patients résistants à PD-(L)1 versus PFS global à 6 mois de 37% chez les progressions antérieures à PD-(L)1 ; six réponses cliniques à 15 mg/kg, dont une réponse complète durable (MCC, 54+ semaines). Sécurité : six événements CRS de grade 1 (tous à 15 mg/kg) et aucun nouveau signal de sécurité (Phase 1 n=98, expansion de dose n=64).
Sensei prévoit des essais de phase 2 en NSCLC 2L et MCC résistant à PD-(L)1 en 2026, sous réserve des retours de la FDA et du financement. Webinaire investisseurs le 20 octobre 2025 à 8h00 ET.
Sensei Biotherapeutics (Nasdaq: SNSE) berichtete Ergebnisse der Phase-1/2-Dosisexpansion für solnerstotug bei der ESMO 2025, die dosisabhängige Aktivität und Verträglichkeit in PD-(L)1-resistenten „heißen“ Tumoren zeigte.
Schlüsseldaten: 6-Monats-PFS 50% bei 15 mg/kg bei PD-(L)1-resistenten Patienten gegenüber einem insgesamt 6-Monats-PFS von 37% über vorangegangene PD-(L)1-Fortschritte; sechs klinische Reaktionen traten bei 15 mg/kg auf, darunter eine nachhaltige komplette Remission (MCC, 54+ Wochen). Sicherheit: sechs Grade-1-CRS-Ereignisse (alle bei 15 mg/kg) und keine neuen Sicherheitssignale (Phase-1-N=98, Dosisexpansion N=64).
Sensei plant Phase-2-Studien in 2L NSCLC und PD-(L)1-resistentem MCC im Jahr 2026, vorbehaltlich FDA-Feedback und Finanzierung. Investoren-Webcast am 20. Okt. 2025 um 8:00 Uhr ET.
Sensei Biotherapeutics (Nasdaq: SNSE) أبلغت عن نتائج المرحلة 1/2 من توسيع الجرعة لـ solnerstotug في ESMO 2025، مبيِّنة نشاطاً وتحمّلاً يعتمد على الجرعة في أورام “حارة” مقاومة لـ PD-(L)1.
البيانات الرئيسية: PFS لمدة 6 أشهر 50% عند 15 mg/kg لدى المرضى المقاومين لـ PD-(L)1 مقارنة بـPFS إجمالي لمدة 6 أشهر قدرها 37% عبر المتقدمين السابقين لـ PD-(L)1؛ ست استجابات سريرية عند 15 mg/kg بما في ذلك استجابة كاملة durable (MCC، 54+ أسبوعاً). السلامة: ست حالات CRS من الدرجة 1 (جميعها عند 15 mg/kg) ولا إشارات سلامة جديدة (Phase 1 عددها 98، توسيع الجرعة 64).
تخطط Sensei لإجراء تجارب في المرحلة 2 في NSCLC من المستوى الثاني و MCC المقاوم لـ PD-(L)1 في 2026، رهناً بتعليقات FDA والتمويل. البث المباشر للمستثمرين في 20 أكتوبر 2025 الساعة 8:00 صباحاً بتوقيت شرق الولايات المتحدة.
Sensei Biotherapeutics (Nasdaq: SNSE) 报告了在ESMO 2025上关于 solnerstotug 的1/2期剂量扩展结果，显示在对 PD-(L)1 具有耐药性的“热”肿瘤中存在剂量依赖的活性和耐受性。
关键数据：6个月PFS 50%，在对 PD-(L)1 有耐药性的患者中为 15 mg/kg，而对所有人群的6个月PFS 为 37%，包括对 PD-(L)1 之前进展的患者；在15 mg/kg 时出现六例临床缓解，其中包括一例持续缓解的完全缓解（MCC，54+周）。安全性方面：六例1级 CRS 事件（均在 15 mg/kg），没有新的安全信号（1期 n=98，剂量扩展 n=64）。
Sensei 计划在2026年启动2L NSCLC 和对 PD-(L)1 有耐药性的 MCC 的II期试验，前提是得到FDA反馈和融资。面向投资者的网络直播将于2025年10月20日美国东部时间上午8:00举行。
- 6-month PFS of 50% at 15 mg/kg in PD-(L)1 resistant patients
- Overall 6-month PFS of 37% in prior PD-(L)1 progressors
- Six clinical responses at 15 mg/kg, including a durable complete response (MCC, 54+ weeks)
- No new safety signals; all CRS events were Grade 1 and manageable
- No objective responses observed at the 3 mg/kg dose
- No responses in MSS colorectal 'cold' tumor cohort (n=20)
- Phase 2 start contingent on FDA feedback and ability to raise sufficient capital
Insights
Phase 1/2 dose expansion shows a dose-dependent signal and tolerable safety, supporting planned Phase 2 work.
At a mechanistic level, the data show the 15 mg/kg dose of solnerstotug combined with cemiplimab produced objective responses and a
Dependencies and risks are clear and constrained to stated facts: safety was largely Grade 1 CRS (six events across Phase 1, n=98), no new safety signals were identified in the dose expansion (n=64), and no responses occurred in the MSS CRC "cold" cohort (n=20). Planned Phase 2 studies are contingent on FDA feedback and the Company’s ability to raise capital, with an expected randomized 2nd-line NSCLC trial and a single-arm Merkel Cell Carcinoma study in
- 6-month progression-free survival (PFS) of
50% in the higher 15 mg/kg dose cohort compares favorably to historical PD-(L)1 refractory settings – - All clinical responses, including a complete response, observed in the higher 15 mg/kg dose cohort –
- Favorable safety profile with six cases of mild, manageable grade 1 cytokine release syndrome (CRS) across all patients treated to date, all of which occurred in the 15 mg/kg dose cohort –
- Data support advancement to Phase 2 studies, currently being planned in Non-Small Cell Lung Cancer and Merkel Cell Carcinoma –
- Sensei to host investor webcast Monday, October 20th at 8:00 AM ET –
BOSTON, Oct. 17, 2025 (GLOBE NEWSWIRE) -- Sensei Biotherapeutics, Inc. (Nasdaq: SNSE), a clinical-stage biotechnology company focused on the discovery and development of next-generation therapeutics for cancer patients, today announced results from the dose expansion portion of its Phase 1/2 trial evaluating solnerstotug (formerly SNS-101), a conditionally active monoclonal antibody targeting VISTA (V-domain Ig suppressor of T cell activation). The data will be shared today during a mini oral session at the ESMO Congress 2025.
The Phase 1 dose expansion is a multi-center, open-label study evaluating solnerstotug as monotherapy and in combination with Libtayo® (cemiplimab), Regeneron’s PD-1 inhibitor. The study enrolled patients with a basket of “hot” tumor types (that typically respond to immunotherapy) (n=44), of whom 41 had previously received and progressed on PD-(L)1 therapy, as well as patients with “cold” tumor types (that typically exhibit primary resistance to immunotherapy) (n=20).
Patients who progress following treatment with PD-(L)1 inhibitors (“secondary resistance”) face a particularly poor prognosis, as resistance to immune checkpoint blockade is a significant challenge in oncology. For patients who develop secondary resistance, the likelihood of benefiting from a rechallenge with the same therapy is estimated to be
Currently, treatment options for PD-(L)1 resistant tumors are limited, with many patients receiving chemotherapy, experimental therapies in clinical trials, or palliative care in the absence of effective alternatives. While historical benchmarks in this setting are limited, docetaxel, which is widely used in the 2nd line post-PD-(L)1 setting for Non-Small Cell Lung Cancer (NSCLC), typically has a 6-month PFS of 10
Emerging Clinical Signal and Favorable Tolerability Profile
As of the September 8, 2025, data cutoff, 35 efficacy-evaluable “hot tumor” patients had received cemiplimab with either 15 mg/kg (n=19) or 3 mg/kg dose (n=16) of solnerstotug. Six clinical responses, including five in patients with PD-(L)1 resistant tumors, occurred at the higher 15 mg/kg solnerstotug dose, and no objective responses were observed at the 3 mg/kg dose.
Among 41 “hot tumor” patients that received and progressed on a prior PD-(L)1 therapy, the overall 6-month PFS rate was
Solnerstotug was well tolerated at both 3 mg/kg and 15 mg/kg doses in combination with cemiplimab:
- Only six mild (Grade 1) CRS events were observed across all patients in Phase 1 (n=98), all manageable.
- No new safety signals were identified across dose expansion (n=64).
- The safety profile remains consistent with prior data and compares favorably to other checkpoint inhibitor combinations in this population.
“We believe solnerstotug’s emerging dose-dependent activity in refractory ‘hot’ tumors, combined with a favorable tolerability profile, support its advancement into Phase 2 studies,” said Ron Weitzman, M.D., Chief Medical Officer of Sensei Biotherapeutics. “The data suggest that selective blockade of VISTA within the tumor microenvironment may help re-engage exhausted T cells, even after PD-1 failure, a goal long considered out of reach.”
In addition to the “hot” tumor cohorts, 20 patients with Microsatellite Stable Colorectal (MSS CRC) “cold” tumors were treated with either solnerstotug as monotherapy or in combination with cemiplimab (350 mg). No responses were observed and the safety profile was consistent with previously reported data.
Durable Disease Control in “Hot” Tumors Followed by Late Onset Responses
Four out of six responders demonstrated prolonged disease control, followed by a late onset response (occurring between 18 and 54 weeks). PD-(L)1 therapies typically have a time to response of 2–3 months, indicating that the combination of solnerstotug plus cemiplimab has a unique and differentiated pattern of activity.
At the 15 mg/kg dose of solnerstotug, notable responses included:
- A Merkel Cell Carcinoma (MCC) patient with a durable complete response at week 18 and a duration of response of 54+ weeks
- A Microsatellite Instability-High Colorectal Cancer (MSI-H CRC) patient with a partial response (PR) at week 36 and a 33+ week duration
- An NSCLC patient with a tumor proportion score less than
5% that was PD-1 naïve had a PR at week 54 and duration of response of 15+ weeks - An Esophageal Cancer patient with a PR at Week 24 and a duration of response of 6 weeks
“This pattern of delayed, durable responses is unusual among immunotherapies,” said Kyriakos Papadopoulos, M.D., Co-Director of Clinical Research at START, San Antonio. “It may indicate that solnerstotug acts through a mechanism that is complementary to PD-(L)1 in resistant tumors.”
Next Steps: Planned Phase 2 Studies to Evaluate Efficacy in a Commercially Attractive Indication and Potentially Pursue Accelerated Approval in a PD-1 Resistant Population
Sensei is planning two Phase 2 studies to begin in 2026, subject to FDA feedback and the Company’s ability to raise sufficient capital. The first is expected to be a randomized trial in 2nd line NSCLC where patients have received and failed anti-PD-(L)1 treatment. Patients would be randomized to receive either the combination of solnerstotug + a PD-(L)1 inhibitor or chemotherapy.
The second trial is expected to be a single arm study in PD-(L)1 resistant MCC patients where there is limited therapeutic optionality and potential for accelerated approval, subject to FDA feedback.
“We’re pleased by the emerging signs of dose-related activity, durability, and a favorable safety profile—key characteristics of a potentially differentiated immunotherapy,” said John Celebi, President and Chief Executive Officer of Sensei Biotherapeutics. “These results provide a foundation for our planned Phase 2 development program as we work to better define solnerstotug’s role in treating challenging patient populations.”
Investor Webcast Information
Sensei will host an investor webcast on October 20th at 8:00 AM ET, featuring company leadership and Kyriakos Papadopoulos, MD, Co-Director of Clinical Research at START, San Antonio.
Register for the event here. A replay will be available after the webcast on the Investor Relations page of Sensei’s website: https://investors.senseibio.com
About Sensei Biotherapeutics
Sensei Biotherapeutics (Nasdaq: SNSE) is a clinical stage biotechnology company focused on the discovery and development of next-generation therapeutics for cancer patients. Through its TMAb™ (Tumor Microenvironment Activated biologics) platform, Sensei develops conditionally active therapeutics designed to disable immunosuppressive signals or activate immunostimulatory signals selectively in the tumor microenvironment to unleash T cells against tumors. Sensei’s lead product candidate is solnerstotug, a conditionally active antibody designed to block the V-domain Ig suppressor of T cell activation (VISTA) checkpoint selectively within the low pH tumor microenvironment, where VISTA acts as a suppressor of T cells by binding the receptor PSGL-1. For more information, please visit www.senseibio.com, and follow the company on X @SenseiBio and LinkedIn.
Cautionary Note Regarding Forward-Looking Statements
Any statements contained in this press release that do not describe historical facts may constitute forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These statements may be identified by words and phrases such as “believe”, “designed to,” “expect”, “may”, “plan”, “potential”, “will”, and similar expressions, and are based on Sensei’s current beliefs and expectations. These forward-looking statements include expectations regarding the development and potential therapeutic benefits of Sensei’s product candidates, including the results of the dose expansion portion of its Phase 1/2 clinical trial of solnerstotug, and its planning of two Phase 2 studies to begin in 2026, subject to FDA feedback and raising sufficient capital. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements. Risks and uncertainties that may cause actual results to differ materially include uncertainties inherent in the development of therapeutic product candidates, such as the risk that any one or more of Sensei’s product candidates will not be successfully developed or commercialized; the risk of delay or cessation of any planned clinical trials of Sensei’s product candidates; the risk that prior results, such as signals of safety, activity or durability of effect, observed from preclinical studies and clinical trials, will not be replicated or will not continue in ongoing or future studies or clinical trials involving Sensei’s product candidates; the risk that Sensei’s product candidates or procedures in connection with the administration thereof will not have the safety or efficacy profile that Sensei anticipates; risks associated with Sensei’s dependence on third-party suppliers and manufacturers, including sole source suppliers, over which Sensei may not always have full control; risks regarding the accuracy of Sensei’s estimates of expenses, capital requirements and needs for additional financing; and other risks and uncertainties that are described in Sensei’s Quarterly Report on Form 10-Q filed with the U.S. Securities and Exchange Commission (SEC) on August 5, 2025 and Sensei’s other Periodic Reports filed with the SEC. Any forward-looking statements speak only as of the date of this press release and are based on information available to Sensei as of the date of this release, and Sensei assumes no obligation to, and does not intend to, update any forward-looking statements, whether as a result of new information, future events or otherwise.
Investor Contact:
Joyce Allaire
LifeSci Advisors
Jallaire@lifesciadvisors.com
1 Kluger HM, et al. J Immunother Cancer 2023
2 Brahmer et al. N Engl J Med. 2015; Borghaei et al. N Engl J Med. 2015.
FAQ
What 6-month PFS did Sensei report for solnerstotug in PD-(L)1 resistant patients (SNSE)?
How many clinical responses were observed with solnerstotug plus cemiplimab in the SNSE trial?
What safety events did Sensei report for solnerstotug (SNSE) in Phase 1?
Did solnerstotug show activity in MSS colorectal 'cold' tumors in the SNSE study?
When will Sensei start Phase 2 trials for solnerstotug and what are the planned indications?
How can investors access Sensei's investor webcast about the SNSE data?
