Plus Therapeutics Presents Positive ReSPECT-LM Clinical Trial Results of REYOBIQ鈩� in Leptomeningeal Metastases
Plus Therapeutics (NASDAQ:PSTV) announced positive results from its ReSPECT-LM Phase 1 trial for REYOBIQ鈩� in treating leptomeningeal metastases (LM). The trial, involving 29 subjects across 6 cohorts, demonstrated significant efficacy with a 76% radiographic and 87% clinical response rate through day 112.
Key outcomes include 100% reduction in CSF tumor cells at day 28, with five of seven patients showing >80% tumor cell reduction surviving at least one year. The median overall survival reached 9 months, substantially better than the typical 4-month survival rate. The study established a recommended Phase 2 single dose of 44.1 mCi, with no dose-limiting toxicities in cohorts 1-4 and manageable safety profile in higher doses.
[ "Clinical benefit rate exceeded 75% in 3 key outcome measures", "Median overall survival of 9 months vs typical 4 months in literature", "100% reduction in CSF tumor cells observed at day 28", "Favorable safety profile with majority of adverse events being Grade 1 and 2", "Five of seven patients with >80% tumor cell reduction survived at least 1 year" ]Plus Therapeutics (NASDAQ:PSTV) ha annunciato risultati positivi dallo studio di Fase 1 ReSPECT-LM su REYOBIQ鈩� nel trattamento delle metastasi leptomeningee (LM). Lo studio, condotto su 29 soggetti distribuiti in 6 coorti, ha mostrato un'efficacia significativa con un 76% di risposta radiografica e l'87% di risposta clinica fino al giorno 112.
Risultati chiave includono una riduzione del 100% delle cellule tumorali nel liquido cerebrospinale (CSF) al giorno 28; cinque dei sette pazienti con >80% di riduzione delle cellule tumorali sono sopravvissuti almeno un anno. La sopravvivenza mediana globale 猫 stata di 9 mesi, nettamente superiore rispetto ai circa 4 mesi riportati in letteratura. Lo studio ha definito una dose raccomandata per la Fase 2 di singola somministrazione di 44,1 mCi, senza tossicit脿 dose-limite nelle coorti 1-4 e con un profilo di sicurezza gestibile anche a dosi pi霉 elevate.
- Il tasso di beneficio clinico ha superato il 75% in 3 risultati chiave
- Sopravvivenza mediana globale di 9 mesi vs ~4 mesi riportati in letteratura
- 100% di riduzione delle cellule tumorali nel CSF osservata al giorno 28
- Profilo di sicurezza favorevole, con la maggior parte degli eventi avversi di Grado 1 e 2
- Cinque dei sette pazienti con >80% di riduzione delle cellule tumorali sono sopravvissuti almeno 1 anno
Plus Therapeutics (NASDAQ:PSTV) anunci贸 resultados positivos del ensayo de Fase 1 ReSPECT-LM con REYOBIQ鈩� para el tratamiento de met谩stasis leptomen铆ngeas (LM). El ensayo, con 29 sujetos en 6 cohortes, mostr贸 eficacia significativa con una respuesta radiogr谩fica del 76% y respuesta cl铆nica del 87% hasta el d铆a 112.
Los resultados clave incluyen una reducci贸n del 100% de c茅lulas tumorales en el LCR al d铆a 28; cinco de siete pacientes con >80% de reducci贸n de c茅lulas tumorales sobrevivieron al menos un a帽o. La supervivencia global mediana alcanz贸 los 9 meses, notablemente superior a los aproximadamente 4 meses t铆picos en la literatura. El estudio estableci贸 una dosis recomendada para la Fase 2 de dosis 煤nica de 44,1 mCi, sin toxicidades limitantes de dosis en las cohortes 1-4 y con un perfil de seguridad manejable en dosis m谩s elevadas.
- Tasa de beneficio cl铆nico superior al 75% en 3 medidas clave
- Supervivencia global mediana de 9 meses vs ~4 meses en la literatura
- 100% de reducci贸n de las c茅lulas tumorales en LCR observada al d铆a 28
- Perfil de seguridad favorable, con la mayor铆a de eventos adversos de Grado 1 y 2
- Cinco de siete pacientes con >80% de reducci贸n de c茅lulas tumorales sobrevivieron al menos 1 a帽o
Plus Therapeutics (NASDAQ:PSTV)電� 霠堨澊鞓る箙(REYOBIQ鈩�)鞚� 靷毄頃� 雵岇矙靾橂 鞝勳澊(Leptomeningeal metastases, LM) 雽�靸� ReSPECT-LM 1靸� 鞁滍棙鞐愳劀 旮嶌爼鞝侅澑 瓴瓣臣毳� 氚滍憸頄堨姷雼堧嫟. 6臧� 旖旐樃韸胳潣 29氇� 彀胳棳鞛愲 歆勴枆霅� 氤� 鞁滍棙鞚� 112鞚检Ц旯岇 鞓侅儊頃欖爜 氚橃潙毳� 76% 氚� 鞛勳儊鞝� 氚橃潙毳� 87%鞚� 鞙犾潣氙疙暅 須姤鞚� 氤挫榾鞀惦媹雼�.
欤检殧 瓴瓣臣搿滊姅 28鞚检Ц 氤奠垬雵岇矙靾橃暋(CSF) 雮� 膦呾枒靹疙彫臧� 100% 臧愳唽頃� 鞝愳澊 韽暔霅橂┌, 膦呾枒靹疙彫臧� >80% 臧愳唽頃� 7氇� 欷� 5氇呾潃 斓滌唽 1雲� 鞚挫儊 靸濎〈頄堨姷雼堧嫟. 鞝勳泊 靸濎〈 欷戩暀臧掛潃 9臧涤洈搿� 氍疙棇靸� 鞚茧皹鞝侅澑 鞎� 4臧滌洈氤措嫟 順勳爛頌� 頄レ儊霅橃棃鞀惦媹雼�. 鞐瓣惮電� 2靸� 甓岇灔 雼澕 韴棳 鞖╇焿鞚� 44.1 mCi搿� 頇曤頄堨溂氅�, 旖旐樃韸� 1-4鞐愳劀 鞖╇焿 鞝滍暅 霃呾劚鞚� 鞐嗢棃瓿� 瓿犾毄霟夓棎靹滊弰 甏�毽� 臧�電ロ暅 鞎堨爠靹� 頂勲韺岇澕鞚� 氤挫榾鞀惦媹雼�.
- 鞛勳儊鞝� 順滍儩毳犾澊 3臧滌潣 欤检殧 韽夑皜鞐愳劀 75%毳� 齑堦臣
- 氍疙棇靸� 鞎� 4臧滌洈 雽�牍� 9臧涤洈鞚� 鞝勳泊 靸濎〈 欷戩暀臧�
- 28鞚检Ц CSF 雮� 膦呾枒靹疙彫 100% 臧愳唽 甏赌彀�
- 雽�攵�攵勳潣 鞚挫儊氚橃潙鞚� 1路2霌标笁鞙茧 鞎堨爠靹� 頂勲韺岇澕 鞏戫樃
- 膦呾枒靹疙彫 >80% 臧愳唽頃� 7氇� 欷� 5氇呾澊 斓滌唽 1雲� 靸濎〈
Plus Therapeutics (NASDAQ:PSTV) a annonc茅 des r茅sultats positifs de l'essai de phase 1 ReSPECT-LM pour REYOBIQ鈩� dans le traitement des m茅tastases leptom茅ning茅es (LM). L'essai, portant sur 29 sujets r茅partis en 6 cohortes, a d茅montr茅 une efficacit茅 significative avec un taux de r茅ponse radiographique de 76% et un taux de r茅ponse clinique de 87% jusqu'au jour 112.
Parmi les r茅sultats cl茅s, on note une r茅duction de 100% des cellules tumorales dans le LCR au jour 28 ; cinq des sept patients pr茅sentant >80% de r茅duction des cellules tumorales ont surv茅cu au moins un an. La survie globale m茅diane a atteint 9 mois, nettement sup茅rieure aux environ 4 mois habituellement rapport茅s. L'茅tude a 茅tabli une dose recommand茅e en phase 2 en administration unique de 44,1 mCi, sans toxicit茅s limitantes de dose dans les cohortes 1-4 et avec un profil de s茅curit茅 g茅rable 脿 des doses plus 茅lev茅es.
- Le taux de b茅n茅fice clinique a d茅pass茅 75% sur 3 crit猫res cl茅s
- Survie globale m茅diane de 9 mois vs ~4 mois dans la litt茅rature
- 100% de r茅duction des cellules tumorales dans le LCR observ茅e au jour 28
- Profil de s茅curit茅 favorable, la majorit茅 des 茅v茅nements ind茅sirables 茅tant de Grades 1 et 2
- Cinq des sept patients avec >80% de r茅duction des cellules tumorales ont surv茅cu au moins 1 an
Plus Therapeutics (NASDAQ:PSTV) gab positive Ergebnisse der ReSPECT-LM Phase鈥�1鈥慡tudie zu REYOBIQ鈩� bei der Behandlung von leptomeningealen Metastasen (LM) bekannt. Die Studie mit 29 Probanden in 6 Kohorten zeigte bis Tag 112 eine deutliche Wirksamkeit mit einer radiographischen Ansprechrate von 76% und einer klinischen Ansprechrate von 87%.
Wesentliche Ergebnisse umfassen eine 100%ige Reduktion von Tumorzellen im Liquor (CSF) am Tag 28; f眉nf von sieben Patient:innen mit >80% Tumorzellreduktion lebten mindestens ein Jahr. Das mediane Gesamt眉berleben lag bei 9 Monaten, deutlich besser als die typischen ca. 4 Monate aus der Literatur. Die Studie legte eine empfohlene Einzeldosis f眉r Phase 2 von 44,1 mCi fest, es traten in den Kohorten 1鈥�4 keine dosislimitierenden Toxizit盲ten auf und das Sicherheitsprofil war auch bei h枚heren Dosen beherrschbar.
- Klinischer Nutzen 眉berstieg in 3 zentralen Endpunkten 75%
- Medianes Gesamt眉berleben 9 Monate vs. typ. 4 Monate in der Literatur
- 100% Reduktion der Tumorzellen im CSF beobachtet am Tag 28
- G眉nstiges Sicherheitsprofil, die Mehrzahl der unerw眉nschten Ereignisse war Grad 1 und 2
- F眉nf von sieben Patient:innen mit >80% Tumorzellreduktion 眉berlebten mindestens 1 Jahr
- None.
- One dose-limiting toxicity of grade 4 cytopenia observed in each of cohorts 5 and 6
Insights
PSTV's REYOBIQ shows impressive 76% radiographic response and 9-month median survival in deadly leptomeningeal metastases, significantly outperforming historical outcomes.
The Phase 1 ReSPECT-LM trial results for REYOBIQ (Rhenium Obisbemeda) demonstrate remarkably positive outcomes in a notoriously difficult-to-treat condition. Leptomeningeal metastases typically carry a dismal prognosis with median survival of approximately 4 months. The 9-month median overall survival observed in cohorts 1-4 represents a potentially significant advancement.
The 76% radiographic response rate and 87% clinical response rate through day 112 are particularly noteworthy. Even more compelling is the 100% reduction in CSF tumor cell enumeration at day 28 and the observation that 5 of 7 patients with >80% tumor cell reduction survived at least one year. These metrics suggest meaningful disease control.
The RNA sequencing data provides valuable mechanistic insights, showing early induction of apoptosis (programmed cell death) followed by immune response activation, indicating a multi-modal effect. This suggests REYOBIQ may not only directly kill tumor cells but potentially sensitize them to immune surveillance.
The safety profile appears manageable with no dose-limiting toxicities in cohorts 1-4, and only grade 4 cytopenia (reduction in blood cells) observed in higher dose cohorts. The selection of 44.1 mCi as the recommended Phase 2 dose strikes a balance between efficacy and safety.
The absorption of 272 Gy to the cranial and spinal subarachnoid space in cohort 6 represents substantial radiation delivery to the target area, which is critical for efficacy in radiotherapeutics.
REYOBIQ produced a clinical benefit rate of over
RNA sequencing and circulating tumor cell reduction consistent with tumor cell death
No dose limiting toxicities were observed with an overall favorable safety profile
HOUSTON, Aug. 18, 2025 (GLOBE NEWSWIRE) -- (狈补蝉诲补辩:听) (the 鈥淐ompany鈥�), a clinical-stage pharmaceutical company developing targeted radiotherapeutics with advanced platform technologies for central nervous system (CNS) cancers, announces positive data from the ReSPECT-LM Phase 1 single dose escalation trial presented at the podium at the SNO/ASCO CNS Metastases Conference in Baltimore, MD. The data demonstrated treatment of leptomeningeal metastases (LM) with REYOBIQ is feasible, has a manageable safety profile, and shows a promising efficacy signal.
The presentation, titled, 鈥淧hase 1 Dose Escalation of Rhenium (186Re) Obisbemeda (Rhenium Nanoliposome,186RNL (REYOBIQ) for the Treatment of Leptomeningeal Metastases (LM): Clinical Study Results for Safety and Efficacy,鈥� highlighted study results to date from a total of 29 subjects in cohorts 1 鈥� 6 who received 6.6 mCi, 13.2 mCi, 26.4 mCi, 44.10 mCi, 66.14 mCi, or 75mCi of REYOBIQ, respectively.
Presented Data Highlights:
- Radiographic and clinical response rate of
76% and87% , respectively, through day 112 - CSF tumor cell enumeration (TCE) assays (CNSide test) showed a maximum reduction over baseline of
100% at day 28 - Five of the 7 patients with a TCE response >
80% survived at least 1 year - RNA sequencing of LM cells showed early induction of apoptosis, with an innate immune response followed by an adaptive immune response by day 28
- Median overall survival of 9 months across cohorts 1-4 (20 patients) months, comparing favorably with literature reports of ~4 months
- No dose-limiting toxicity (DLT) was observed in cohorts 1-4, with 1 DLT in each of cohorts 5 and 6 of grade 4 cytopenia
- The majority of adverse events across the trial were Grade 1 and 2
- Mean absorbed dose to the cranial and spinal subarachnoid space was 272 Gy in cohort 6听听
- A recommended phase 2 single dose of 44.1 mCi was determined听听
鈥淩esponses were observed in early cohorts with excellent tolerance at much higher doses supporting a broad therapeutic range,鈥� said Dr. Andrew Brenner, M.D., Ph.D., Professor of Medicine in the Division of Hematology and Oncology at The University of Texas Health Science Center at San Antonio. 鈥淔urthermore, the trial gave us exactly what we needed to move into the ongoing dosing optimization trial and then to a potential approval trial.鈥�
About LM
Leptomeningeal metastases (LM) are a rare but severe complication of advanced cancer, affecting the fluid-lined structures of the central nervous system. LM occurs in approximately
About REYOBIQ鈩� (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, leptomeningeal metastases, and pediatric brain cancer in the ReSPECT-GBM, ReSPECT-LM, and ReSPECT-PBC 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 CNSide Diagnostic, LLC
CNSide Diagnostics, LLC is a wholly owned subsidiary of Plus Therapeutics, Inc. that develops and commercializes proprietary laboratory-developed tests, such as CNSide庐, designed to identify tumor cells that have metastasized to the central nervous system in patients with carcinomas and melanomas. The CNSide庐 CSF Assay Platform enables quantitative analysis and molecular characterization of tumor cells and circulating tumor DNA in the cerebrospinal fluid that inform and improve the management of patients with leptomeningeal metastases.
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 .
Forward-Looking Statements
This press release contains statements that may be deemed 鈥渇orward-looking statements鈥� within the meaning of U.S. securities laws, including statements regarding clinical trials, expected operations and upcoming developments. All statements in this press release other than statements of historical fact are forward-looking statements. These forward-looking statements may be identified by future verbs, as well as terms such as 鈥渆xpect鈥� 鈥減otential,鈥� 鈥渁nticipating,鈥� 鈥減lanning鈥� and similar expressions or the negatives thereof. Such statements are based upon certain assumptions and assessments made by management in light of their experience and their perception of historical trends, current conditions, expected future developments and other factors they believe to be appropriate.
The forward-looking statements included in this press release could differ materially from those expressed or implied by these forward-looking statements because of risks, uncertainties, and other factors that include, but are not limited to, the following: the Company鈥檚 ability to maintain the listing of its common stock on Nasdaq; risks related to a halt in trading or delisting of the Company鈥檚 common stock on Nasdaq; Medicare and private payors may not provide coverage and reimbursement or may breach, rescind or modify their contracts or reimbursement policies or delay payments; the risk that our products and services may not perform as expected; the early stage of the Company鈥檚 product candidates and therapies; the results of the Company鈥檚 research and development activities, including uncertainties relating to the clinical trials of its product candidates and therapies; the Company鈥檚 liquidity and capital resources and its ability to raise additional cash; the outcome of the Company鈥檚 partnering/licensing efforts, risks associated with laws or regulatory requirements applicable to it; market conditions, product performance, litigation or potential litigation, and competition within the cancer diagnostics and therapeutics field; ability to develop and protect proprietary intellectual property or obtain licenses to intellectual property developed by others on commercially reasonable and competitive terms; challenges associated with radiotherapeutic manufacturing, production and distribution capabilities necessary to support the Company鈥檚 clinical trials and any commercial level product demand; and material security breach or cybersecurity attack affecting the Company鈥檚 operations or property. This list of risks, uncertainties, and other factors is not complete. Plus Therapeutics discusses some of these matters more fully, as well as certain risk factors that could affect Plus Therapeutics鈥� business, financial condition, results of operations, and prospects, in its reports filed with the SEC, including Plus Therapeutics鈥� annual report on Form 10-K for the fiscal year ended December 31, 2024, quarterly reports on Form 10-Q, and current reports on Form 8-K. These filings are available for review through the SEC鈥檚 website at www.sec.gov. Any or all forward-looking statements Plus Therapeutics makes may turn out to be wrong and can be affected by inaccurate assumptions Plus Therapeutics might make or by known or unknown risks, uncertainties, and other factors, including those identified in this press release. Accordingly, you should not place undue reliance on the forward-looking statements made in this press release, which speak only as of its date. The Company assumes no responsibility to update or revise any forward-looking statements to reflect events, trends or circumstances after the date they are made unless the Company has an obligation under U.S. federal securities laws to do so.
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FAQ
What were the key results of Plus Therapeutics' (PSTV) ReSPECT-LM trial for REYOBIQ?
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