Plus Therapeutics’ REYOBIQ™ Shows Clinical Benefit and Safety in the ReSPECT-LM Clinical Trial for Patients with Leptomeningeal Metastases (LM)
Plus Therapeutics (NASDAQ: PSTV) presented new data for REYOBIQ™ (rhenium Re186 obisbemeda) from its Phase 1 ReSPECT-LM trial for Leptomeningeal Metastases (LM) at the 2025 Nuclear Medicine and Neurooncology Conference. Key findings include:
The trial demonstrated significant clinical benefits with a 76% Clinical Benefit Rate (13/17 patients showing partial response or stable disease) and 87% clinical response rate based on physician evaluation. The treatment showed dose-dependent effectiveness, reaching 253Gy in Cohort 5.
Notably, 5 out of 7 patients who showed >80% reduction in LM tumor cells survived at least one year after initial treatment, with three receiving additional treatment under compassionate use. RNA sequencing revealed early tumor cell death and enhanced immune response, while maintaining a favorable safety profile with limited dose-limiting toxicities.
Plus Therapeutics (NASDAQ: PSTV) ha presentato nuovi dati su REYOBIQ™ (rhenium Re186 obisbemeda) provenienti dal suo studio di Fase 1 ReSPECT-LM per le Metastasi Leptomeningee (LM) durante la Conferenza di Medicina Nucleare e Neurooncologia 2025. I risultati principali includono:
Lo studio ha evidenziato benefici clinici significativi con un tasso di beneficio clinico del 76% (13 su 17 pazienti hanno mostrato risposta parziale o malattia stabile) e un tasso di risposta clinica dell'87% basato sulla valutazione medica. Il trattamento ha mostrato efficacia dipendente dalla dose, raggiungendo 253Gy nel Gruppo 5.
In particolare, 5 pazienti su 7 che hanno mostrato una riduzione superiore all'80% delle cellule tumorali LM sono sopravvissuti almeno un anno dopo il trattamento iniziale, di cui tre hanno ricevuto ulteriori terapie in uso compassionevole. Il sequenziamento dell'RNA ha evidenziato una precoce morte delle cellule tumorali e un aumento della risposta immunitaria, mantenendo un profilo di sicurezza favorevole con tossicità limitate legate alla dose.
Plus Therapeutics (NASDAQ: PSTV) presentó nuevos datos de REYOBIQ™ (rhenium Re186 obisbemeda) de su ensayo de Fase 1 ReSPECT-LM para Metástasis Leptomeníngeas (LM) en la Conferencia de Medicina Nuclear y Neurooncología 2025. Los hallazgos clave incluyen:
El ensayo demostró beneficios clínicos significativos con una tasa de beneficio clínico del 76% (13 de 17 pacientes mostraron respuesta parcial o enfermedad estable) y una tasa de respuesta clínica del 87% según la evaluación médica. El tratamiento mostró efectividad dependiente de la dosis, alcanzando 253Gy en el Grupo 5.
Notablemente, 5 de 7 pacientes que mostraron una reducción superior al 80% en las células tumorales LM sobrevivieron al menos un año después del tratamiento inicial, con tres recibiendo tratamiento adicional bajo uso compasivo. La secuenciación de ARN reveló muerte temprana de células tumorales y una respuesta inmune mejorada, manteniendo un perfil de seguridad favorable con toxicidades limitadas relacionadas con la dosis.
Plus Therapeutics (NASDAQ: PSTV)는 2025년 핵의학 및 신경종양학 회의에서 뇌척수막 전이(Leptomeningeal Metastases, LM)를 위한 1상 ReSPECT-LM 임상시험의 REYOBIQ™ (rhenium Re186 obisbemeda) 신규 데이터를 발표했습니다. 주요 결과는 다음과 같습니다:
임상시험에서 76% 임상 혜택률 (17명 중 13명이 부분 반응 또는 안정된 질병 상태를 보임)과 의사 평가 기준 87% 임상 반응률을 입증했습니다. 치료는 용량 의존적 효과를 나타내어 5번째 코호트에서 253Gy에 도달했습니다.
특히, 7명 중 5명이 LM 종양 세포가 80% 이상 감소한 후 초기 치료 후 최소 1년 이상 생존했으며, 이 중 3명은 동정적 사용 하에 추가 치료를 받았습니다. RNA 시퀀싱 결과 조기 종양 세포 사멸과 향상된 면역 반응이 나타났으며, 제한된 용량 제한 독성으로 안전성 프로파일도 우수했습니다.
Plus Therapeutics (NASDAQ : PSTV) a présenté de nouvelles données concernant REYOBIQ™ (rhénium Re186 obisbemeda) issues de son essai de phase 1 ReSPECT-LM pour les métastases leptomeningées (LM) lors de la conférence 2025 de médecine nucléaire et neuro-oncologie. Les résultats clés incluent :
L'essai a démontré des bénéfices cliniques significatifs avec un taux de bénéfice clinique de 76% (13 patients sur 17 présentant une réponse partielle ou une maladie stable) et un taux de réponse clinique de 87% basé sur l’évaluation des médecins. Le traitement a montré une efficacité dépendante de la dose, atteignant 253 Gy dans la cohorte 5.
Notamment, 5 patients sur 7 ayant présenté une réduction de plus de 80% des cellules tumorales LM ont survécu au moins un an après le traitement initial, dont trois ont reçu un traitement supplémentaire en usage compassionnel. Le séquençage ARN a révélé une mort précoce des cellules tumorales et une réponse immunitaire renforcée, tout en maintenant un profil de sécurité favorable avec des toxicités limitantes liées à la dose réduites.
Plus Therapeutics (NASDAQ: PSTV) präsentierte neue Daten zu REYOBIQ™ (Rhenium Re186 obisbemeda) aus der Phase-1-Studie ReSPECT-LM für Leptomeningeale Metastasen (LM) auf der Konferenz für Nuklearmedizin und Neuroonkologie 2025. Wichtige Ergebnisse umfassen:
Die Studie zeigte signifikante klinische Vorteile mit einer klinischen Nutzenrate von 76% (13 von 17 Patienten zeigten partielle Remission oder stabile Erkrankung) und einer klinischen Ansprechrate von 87% basierend auf der ärztlichen Bewertung. Die Behandlung zeigte eine dosisabhängige Wirksamkeit und erreichte 253 Gy in Kohorte 5.
Bemerkenswert ist, dass 5 von 7 Patienten, die eine >80% Reduktion der LM-Tumorzellen zeigten, mindestens ein Jahr nach der Erstbehandlung überlebten, wobei drei von ihnen eine zusätzliche Behandlung im Rahmen der humanitären Anwendung erhielten. Die RNA-Sequenzierung zeigte frühes Tumorzelltod und eine verstärkte Immunantwort, während das Sicherheitsprofil mit begrenzten dosislimitierenden Toxizitäten günstig blieb.
- 76% Clinical Benefit Rate (13/17 patients) showing partial response or stable disease
- 87% clinical response rate based on physician evaluation
- 5 out of 7 patients with >80% tumor cell reduction survived at least one year
- RNA sequencing showed positive mechanism of action with early tumor death and immune response
- Multiple doses possible under compassionate use, suggesting potential for long-term treatment
- Grade 4 dose-limiting toxicity (thrombocytopenia) observed in Cohorts 5 and 6
Insights
REYOBIQ shows promising clinical benefit in leptomeningeal metastases with 76% clinical benefit rate and long-term survivors among retreated patients.
Plus Therapeutics has presented compelling new data for REYOBIQ™ (rhenium Re186 obisbemeda) in treating leptomeningeal metastases (LM), a rare and devastating condition where cancer spreads to the fluid and tissues surrounding the brain and spinal cord. The results from their Phase 1 ReSPECT-LM trial demonstrate several important clinical outcomes.
The data shows a dose-dependent therapeutic effect, with absorption reaching an impressive 253Gy in the highest cohort. Among the 17 patients with available neuroimaging data, 5 patients (29%) achieved partial responses and 8 patients showed stable disease, yielding a clinical benefit rate of 76%. This is particularly significant for LM, which typically has a dismal prognosis with median survival often measured in weeks to a few months.
What's most striking about this data is the durability of response. Of seven patients who showed greater than 80% reduction in LM tumor cells in cerebrospinal fluid, five survived at least one year after initial treatment. Three of these patients received compassionate use retreatment, suggesting that REYOBIQ might be effectively administered as a repeated therapy.
The mechanistic data is equally impressive, with RNA sequencing revealing early induction of apoptosis (programmed cell death) followed by both innate and adaptive immune responses by Day 28. This dual mechanism—direct tumor cell killing plus immune activation—suggests REYOBIQ may offer advantages over conventional therapies.
Safety appears manageable with dose-limiting toxicity (thrombocytopenia) only observed at the highest dose cohorts (5 and 6), indicating a favorable therapeutic window. For a condition with few effective treatment options, these results represent meaningful progress toward addressing a significant unmet medical need.
Multiple long-term LM survivors in those patients receiving multiple doses of REYOBIQ
RNA sequencing data show early tumor apoptosis and activation of innate immune responses
Updated ReSPECT data presented at the 2025 Nuclear Medicine and Neurooncology Conference
HOUSTON, May 14, 2025 (GLOBE NEWSWIRE) -- Plus Therapeutics, Inc. (Nasdaq: PSTV) (the “Company”), a clinical-stage pharmaceutical company developing targeted radiotherapeutics with advanced platform technologies for central nervous system (CNS) cancers, announces the presentation of new data on its lead drug REYOBIQ™ (rhenium Re186 obisbemeda) during both an oral presentation and a poster presented at the Nuclear Medicine and Neurooncology Conference. The meeting was held May 9-10, 2025 in Vienna, Austria.
"This newly presented data shows safety, clinical benefit and data supporting the underlying mechanism of action for REYOBIQ in patients with Leptomeningeal Metastases," said Marc H. Hedrick, M.D., Plus Therapeutics President and Chief Executive Officer. "Furthermore, multiple doses of REYOBIQ were administered under compassionate use, mirroring how REYOBIQ may one day be used post approval and can contribute to long term survival in LM.”
The study, titled, “Rhenium Obisbemeda (REYOBIQ) in Leptomeningeal Metastases,” highlights additional data from the Company’s now complete Phase 1 ReSPECT-LM dose escalation trial. The presented data added further detail to the previously reported data from the submitted abstract, which demonstrated:
- Dose dependent increase in the average absorbed dose to the cranial and spinal subarachnoid space reaching 253Gy in Cohort 5
- Neuroimaging response data was available for 17 patients as of the data cutoff with five of those (
29% ) showing a partial response - An additional eight patients showed stable disease by neuroimaging through day 112 for a Clinical Benefit Rate (complete response + partial response + stable disease) of
76% (13/17 – five partial responses and eight stable disease). Additionally,87% of subjects demonstrated clinical response based on the physician evaluation (13/15 – 2 response and 11 stable disease) - No dose limiting toxicity (DLT) observed in the first four cohorts, with a grade 4 DLT (thrombocytopenia), one in each of Cohorts 5 and 6
- RNA sequencing of LM cells showed early induction of apoptosis, with an innate immune response followed by an increase in T cells and an adaptive immune response by Day 28.
- In addition, of the seven patients who received a response of better than
80% in reduction of LM tumor cells in the cerebrospinal fluid, five survived at least one year following initial treatment. - The study reports that three of those five were retreated via compassionate use.
Further details from the poster can be found here.
About Leptomeningeal Metastases (LM)
LM is a rare complication of cancer in which the primary cancer spreads to the cerebrospinal fluid (CSF) and leptomeninges surrounding the brain and spinal cord. All malignancies originating from solid tumors, primary brain tumors, or hematological malignancies have this LM complication potential with breast cancer as the most common cancer linked to LM, with 3
About REYOBIQ™ (rhenium Re186 obisbemeda)
REYOBIQ™ (rhenium Re186 obisbemeda) is a novel injectable radiotherapy specifically formulated to deliver direct targeted high dose radiation in CNS tumors in a safe, effective, and convenient manner to optimize patient outcomes. REYOBIQ™ has the potential to reduce off target risks and improve outcomes for CNS cancer patients, versus currently approved therapies, with a more targeted and potent radiation dose. Rhenium-186 is an ideal radioisotope for CNS therapeutic applications due to its short half-life, beta energy for destroying cancerous tissue, and gamma energy for real-time imaging. REYOBIQ™ is being evaluated for the treatment of recurrent glioblastoma and leptomeningeal metastases in the ReSPECT-GBM and ReSPECT-LM clinical trials. ReSPECT-GBM is supported by an award from the National Cancer Institute (NCI), part of the U.S. National Institutes of Health (NIH), and ReSPECT-LM is funded by a three-year
About Plus Therapeutics
Headquartered in Houston, Texas, Plus Therapeutics, Inc. is a clinical-stage pharmaceutical company developing targeted radiotherapeutics for difficult-to-treat cancers of the central nervous system with the potential to enhance clinical outcomes. Combining image-guided local beta radiation and targeted drug delivery approaches, the Company is advancing a pipeline of product candidates with lead programs in leptomeningeal metastases (LM) and recurrent glioblastoma (GBM). The Company has built a supply chain through strategic partnerships that enable the development, manufacturing, and future potential commercialization of its products. For more information, visit https://plustherapeutics.com/.
Investor Contact
CORE IR
investor@plustherapeutics.com
FAQ
What are the key clinical results of PSTV's REYOBIQ Phase 1 trial for Leptomeningeal Metastases?
What is the survival rate for PSTV's REYOBIQ treatment in LM patients?
What are the side effects of PSTV's REYOBIQ treatment in the Phase 1 trial?
How does PSTV's REYOBIQ work against Leptomeningeal Metastases?
What was the maximum radiation dose achieved in PSTV's REYOBIQ trial?
