Sensei Biotherapeutics Reports Favorable Preliminary Dose Expansion Data for Solnerstotug in PD-(L)1 Resistant Tumors
Sensei Biotherapeutics (NASDAQ: SNSE) has reported promising preliminary results from its Phase 1/2 trial of solnerstotug, a conditionally active antibody targeting VISTA. The drug showed significant clinical activity in PD-(L)1 resistant tumors, achieving a 14% overall response rate - nearly triple the historical rechallenge rates of ≤5%.
Key findings include:
- One durable complete response in Merkel Cell Carcinoma (MCC)
- Two partial responses in MCC and MSI-H Colorectal Cancer patients
- 62% disease control rate among 21 evaluable PD-(L)1 resistant patients
- All patients with tumor shrinkage remain on treatment
The drug demonstrated favorable safety with no dose-limiting toxicities, mostly Grade 1-2 adverse events, and only 7% cases of mild cytokine release syndrome. Subject to capital raising, Sensei plans to initiate Phase 2 studies in Q1 2026.
Sensei Biotherapeutics (NASDAQ: SNSE) ha riportato risultati preliminari promettenti dal suo trial di Fase 1/2 di solnerstotug, un anticorpo attivo condizionatamente che mira a VISTA. Il farmaco ha mostrato un'attività clinica significativa nei tumori resistenti a PD-(L)1, raggiungendo un 14% di tasso di risposta complessivo - quasi triplo rispetto ai tassi storici di riconsiderazione di ≤5%.
I principali risultati includono:
- Una risposta completa duratura nel Carcinoma a Cellule di Merkel (MCC)
- Due risposte parziali in pazienti con MCC e Cancro Colorettale MSI-H
- 62% di tasso di controllo della malattia tra 21 pazienti valutabili resistenti a PD-(L)1
- Tutti i pazienti con riduzione del tumore rimangono in trattamento
Il farmaco ha dimostrato un profilo di sicurezza favorevole, senza tossicità limitanti da dose, per lo più eventi avversi di Grado 1-2, e solo il 7% dei casi di sindrome da rilascio di citochine lieve. Soggetta a raccolta di capitali, Sensei prevede di avviare studi di Fase 2 nel Q1 2026.
Sensei Biotherapeutics (NASDAQ: SNSE) ha reportado resultados preliminares prometedores de su ensayo de Fase 1/2 de solnerstotug, un anticuerpo activado condicionalmente que se dirige a VISTA. El fármaco mostró una actividad clínica significativa en tumores resistentes a PD-(L)1, logrando un 14% de tasa de respuesta global - casi el triple de las tasas históricas de reexamen de ≤5%.
Los hallazgos clave incluyen:
- Una respuesta completa duradera en Carcinoma de Células de Merkel (MCC)
- Dos respuestas parciales en pacientes con MCC y Cáncer Colorrectal MSI-H
- 62% de tasa de control de la enfermedad entre 21 pacientes evaluables resistentes a PD-(L)1
- Todos los pacientes con reducción del tumor permanecen en tratamiento
El fármaco demostró una seguridad favorable sin toxicidades limitantes por dosis, en su mayoría eventos adversos de Grado 1-2, y solo el 7% de casos de síndrome leve de liberación de citoquinas. Sujeto a la recaudación de capital, Sensei planea iniciar estudios de Fase 2 en el Q1 de 2026.
센세이 생명과학(Sensei Biotherapeutics) (NASDAQ: SNSE)는 VISTA를 표적으로 하는 조건부 활성 항체 솔너스토투그(solnerstotug)의 1/2상 시험에서 유망한 초기 결과를 보고했습니다. 이 약물은 PD-(L)1 저항성 종양에서 유의미한 임상 활성을 보여주었으며, 14%의 전체 반응률을 달성했습니다 - 이는 역사적인 재도전율 ≤5%의 거의 세 배에 해당합니다.
주요 발견 사항은 다음과 같습니다:
- 머켈 세포 암종(MCC)에서의 지속적인 완전 반응 1건
- MCC 및 MSI-H 대장암 환자에서의 부분 반응 2건
- PD-(L)1 저항성 환자 21명 중 62%의 질병 조절율
- 종양 축소가 있는 모든 환자가 치료를 계속 받고 있음
이 약물은 용량 제한 독성이 없고, 대부분 1-2등급의 부작용과 단지 7%의 경증 사이토카인 방출 증후군 사례로 안전성이 우수함을 입증했습니다. 자본 조달이 이루어질 경우, 센세이는 2026년 1분기에 2상 연구를 시작할 계획입니다.
Sensei Biotherapeutics (NASDAQ: SNSE) a rapporté des résultats préliminaires prometteurs de son essai de Phase 1/2 sur solnerstotug, un anticorps activé conditionnellement ciblant VISTA. Le médicament a montré une activité clinique significative dans les tumeurs résistantes à PD-(L)1, atteignant un taux de réponse global de 14% - presque trois fois supérieur aux taux de rechallenge historiques de ≤5%.
Les principales conclusions incluent:
- Une réponse complète durable dans le carcinome à cellules de Merkel (MCC)
- Deux réponses partielles chez des patients atteints de MCC et de cancer colorectal MSI-H
- 62% de taux de contrôle de la maladie parmi 21 patients résistants à PD-(L)1 évaluables
- Tous les patients ayant une réduction tumorale restent en traitement
Le médicament a démontré un profil de sécurité favorable sans toxicités limitantes de dose, principalement des événements indésirables de Grade 1-2, et seulement 7% de cas de syndrome léger de libération de cytokines. Sous réserve de levée de fonds, Sensei prévoit de lancer des études de Phase 2 au premier trimestre 2026.
Sensei Biotherapeutics (NASDAQ: SNSE) hat vielversprechende vorläufige Ergebnisse aus seiner Phase 1/2-Studie zu solnerstotug, einem bedingt aktiven Antikörper, der auf VISTA abzielt, berichtet. Das Medikament zeigte eine signifikante klinische Aktivität bei PD-(L)1-resistenten Tumoren und erreichte eine 14% Gesamtansprechrate - fast dreimal so hoch wie die historischen Wiederherstellungsraten von ≤5%.
Wichtige Ergebnisse umfassen:
- Eine dauerhafte komplette Remission bei Merkelzellkarzinom (MCC)
- Zwei partielle Remissionen bei Patienten mit MCC und MSI-H-Kolonkarzinom
- 62% Krankheitskontrollrate unter 21 auswertbaren PD-(L)1-resistenten Patienten
- Alle Patienten mit Tumorreduktion bleiben in Behandlung
Das Medikament zeigte ein günstiges Sicherheitsprofil ohne dosislimitierende Toxizität, überwiegend Grad 1-2 unerwünschte Ereignisse und nur 7% Fälle von mildem Zytokinfreisetzungssyndrom. Vorbehaltlich der Kapitalbeschaffung plant Sensei, im ersten Quartal 2026 Phase-2-Studien zu starten.
- 14% overall response rate in PD-(L)1 resistant tumors, nearly triple the historical rates
- 62% disease control rate in evaluable patients
- Favorable safety profile with no dose-limiting toxicities
- Durable complete response in one MCC patient at 42+ weeks
- All patients with tumor shrinkage remain on treatment, suggesting lasting benefits
- No responses observed in MSS CRC 'cold' tumor patients
- Phase 2 trial initiation dependent on raising additional capital
- 8 patients discontinued study before first post-baseline scan
- dataset with only 21 evaluable patients in 'hot' tumor group
Insights
The preliminary dose expansion data for solnerstotug in PD-(L)1 resistant tumors represents a potentially significant clinical advancement in a notoriously difficult-to-treat patient population. The 14% overall response rate observed in PD-(L)1 resistant "hot" tumors is approximately triple the expected ≤5% response rate typically seen with PD-(L)1 rechallenge in resistant patients.
The complete response in Merkel Cell Carcinoma is particularly noteworthy, as durable CRs in immunotherapy-resistant MCC are exceedingly rare. Additionally, the 62% disease control rate and the fact that all patients with tumor shrinkage remain on treatment suggests potential for sustained clinical benefit.
From a clinical perspective, the safety profile appears manageable with only 7% Grade 1 cytokine release syndrome and primarily Grade 1-2 adverse events. This contrasts favorably with existing combination approaches like CTLA-4+PD-1, which can cause treatment discontinuation in up to 40% of patients due to severe immune-related adverse events.
However, caution is warranted given the small sample size of 21 evaluable patients and relatively early data maturity. The lack of response in microsatellite stable (MSS) CRC patients also highlights limitations of this approach in "cold" tumors. The company's explicit mention of needing to raise capital before initiating Phase 2 in Q1 2026 introduces uncertainty around the program's advancement timeline.
These favorable preliminary dose expansion results represent a meaningful clinical value inflection point for Sensei Bio's lead asset. The 14% response rate in checkpoint-resistant patients significantly outperforms historical benchmarks and compares favorably to competing approaches in this space, potentially positioning solnerstotug as a differentiated therapy in the substantial PD-(L)1 resistant market.
The durable patient benefit - including one complete response at 42+ weeks and stable disease patients remaining on treatment beyond 12 weeks - suggests sustainable efficacy that could translate to improved progression-free survival metrics in larger studies. The 62% disease control rate further supports the drug's clinical activity.
However, I'm particularly focused on the explicit capital requirements mentioned for advancing to Phase 2. With a current market cap of just
The promising efficacy data, especially in Merkel Cell Carcinoma and MSI-H colorectal cancer, could potentially attract partnership interest from larger oncology players seeking novel checkpoint targets beyond the crowded PD-1 space. VISTA's mechanism as a conditionally active approach differentiates it from conventional checkpoint inhibitors and could support development in specific indications where initial signals are strongest.
– Initial clinical activity in a PD-(L)1 resistant population, with an ORR almost three times higher than historical PD-(L)1 rechallenge response rates, with data still maturing –
– One durable complete response in a Merkel Cell Carcinoma (MCC) patient and two partial responses (PR), including one in a second MCC patient and one in a microsatellite instability-high (MSI-H) Colorectal Cancer (CRC) patient, all of whom were previously treated with and progressed on immunotherapy –
– All PD-(L)1 resistant “hot” tumor patients with tumor shrinkage remain on study, suggesting potential for deepening responses over time –
– Sensei to host investor webcast today at 5:30 p.m. ET –
BOSTON, March 27, 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 initial 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).
“Checkpoint inhibitor resistance remains a significant challenge for patients with advanced cancer, with limited treatment options beyond chemotherapy or clinical trials,” said Ron Weitzman, M.D., Chief Medical Officer of Sensei Biotherapeutics. “Historically, patients who progress on PD-(L)1 therapy are estimated to have a ≤
Phase 1 Dose Expansion Preliminary Results
The Phase 1 dose expansion trial is a multi-center, open-label, dose expansion study evaluating solnerstotug as monotherapy and in combination with Libtayo® (cemiplimab), Regeneron’s PD-1 inhibitor, in both a basket of “hot” tumors that typically respond to immunotherapy but have progressed on prior PD-(L)1 therapy and a single “cold” tumor histology (microsatellite stable (MSS) CRC) that is typically unresponsive to immunotherapy.
As of March 17, 2025, the study has enrolled 60 patients, including:
- 40 patients with “hot” tumors, including Non-Small Cell Lung Cancer (NSCLC), Head and Neck (H&N) cancer, Melanoma, Renal Cell Carcinoma (RCC), Merkel Cell Carcinoma (MCC), MSI-H Colorectal Cancer (CRC), and other tumor types. All patients received the combination of solnerstotug (3 mg/kg or 15 mg/kg) and cemiplimab.
- At the time of this data cut, 21 “hot” tumor PD-(L)1 resistant patients were considered evaluable for efficacy, having received at least one post-baseline scan. An additional 11 patients have not yet reached the first baseline scan, and an additional 8 patients discontinued the study prior to any post-baseline scan.
- 20 patients with PD-(L)1 non-responsive microsatellite stable (MSS) Colorectal Cancer (CRC) were included to assess potential activity in “cold” tumors. Of these patients, 10 were enrolled in a monotherapy (15 mg/kg) cohort and 10 received the combination of solnerstotug (15 mg/kg) and cemiplimab.
- 17 MSS CRC patients were considered evaluable for efficacy, having received at least one post-baseline scan. Three patients discontinued the study prior to any post-baseline scan.
Key findings include:
14% ORR (3 patients) and62% DCR (disease control rate) (13 patients) among 21 evaluable PD-(L)1 resistant “hot” tumor patients.- Durable complete response (CR) in a MCC patient treated with 15 mg/kg solnerstotug + cemiplimab. Patient continues on treatment at 42+ weeks. Previously received a PD-(L)1 therapy for 15 months in the adjuvant setting prior to progressing on therapy.
- Partial response (PR) at Week 12 in a MCC patient treated with 15 mg/kg solnerstotug + cemiplimab. Patient continues on treatment at 12+ weeks. Previously received several lines of checkpoint therapy, including the combination of PD-1 and CTLA-4, with a best response of stable disease prior to progressing on therapy.
- Partial response (PR) at Week 36 in an MSI-H CRC patient treated with 15 mg/kg solnerstotug + cemiplimab. Patient had durable stable disease (SD) through the course of treatment before converting to a PR at Week 36. Patient continues on treatment at 36+ weeks. Previously received a PD-(L)1 therapy for more than 4 years, where the patient achieved a CR prior to progressing on therapy.
- Six PD-(L)1 resistant patients with SD remain on treatment past 12+ weeks, with tumor reductions ranging from
0% to17% , suggesting durable disease control in a subset of patients. - All PD-(L)1 resistant patients on study with tumor shrinkage remain on treatment, suggesting potential for prolonged benefit.
- None of the MSS CRC patients experienced a CR or PR, consistent with prior checkpoint therapy in this “cold” tumor type.
Solnerstotug continues to be well tolerated, with no dose-limiting toxicities and the majority of AEs Grade 1 or 2 in severity. Out of 60 patients, there have been four (
A Challenging Treatment Landscape for PD-(L)1 Resistant Tumors
Patients who progress following treatment with PD-1 or PD-L1 inhibitors (“secondary resistance”) face a particularly poor prognosis, as resistance to immune checkpoint blockade is a significant challenge in oncology. According to the Society for Immunotherapy of Cancer (SITC), secondary resistance is defined as disease progression following an initial period of disease control. For patients who develop secondary resistance after treatment with PD-(L)1 immune checkpoint inhibitors, the likelihood of benefiting from a rechallenge with the same therapy is estimated to be
"While we remain in the early stages of evaluating solnerstotug’s therapeutic potential, the observed responses—particularly in MCC and MSI-H CRC—are encouraging given the historically poor prognosis of these patients once they have progressed on checkpoint therapy,” said Dr. Shiraj Sen, M.D., Medical Oncologist and Director of Clinical Research at NEXT Oncology - Dallas, and a Principal Investigator for the solnerstotug study. “Continued clinical evaluation will be key in determining which patients are most likely to benefit from this approach.”
Next Steps: Preparing for Phase 2
Subject to raising sufficient capital, Sensei plans to initiate a Phase 2 study in Q1 2026, with the trial design and patient selection strategies to be informed by the ongoing dose expansion results. Further analyses, including biomarker-based patient selection, are underway to optimize the Phase 2 design.
Investor Webcast Information
Sensei will host an investor webcast today at 5:30 p.m. ET, featuring company leadership and Dr. Shiraj Sen, M.D., Ph.D., Medical Oncologist and Director of Clinical Research at NEXT Oncology-Dallas, an investigator in the Phase 1/2 study.
Access the live event here: https://lifescievents.com/event/sensei-bio-2/
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 developing next-generation immunotherapies for cancer. Through its TMAb™ (Tumor Microenvironment Activated biologics) platform, Sensei engineers conditionally active therapeutics designed to modulate immune responses within the tumor microenvironment. The company’s lead product candidate, solnerstotug, is a VISTA-targeting monoclonal antibody designed to restore T cell activity in checkpoint inhibitor-resistant tumors. For more information, visit www.senseibio.com and follow Sensei 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, the timing of Sensei’s Phase 1/2 clinical trial of solnerstotug (SNS-101), including reporting of data therefrom, and its plans to initiate a Phase 2 study in the first quarter of 2026, subject to 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 November 14, 2024 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.
- Kluger H, et al. J immunother Cancer 2023
Investor Contact:
Michael Biega
Senior Director, Investor Relations
Sensei Biotherapeutics
mbiega@senseibio.com
Media Contact:
Joyce Allaire
LifeSci Advisors
Jallaire@lifesciadvisors.com
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