Plus Therapeutics Announces FDA Agreement to Initiate ReSPECT-LM Dose Optimization Trial for REYOBIQ鈩� in Leptomeningeal Metastases
Plus Therapeutics (NASDAQ:PSTV) has announced FDA agreement to initiate the ReSPECT-LM dose optimization trial for REYOBIQ鈩� (rhenium Re186 obisbemeda) in treating leptomeningeal metastases (LM). The trial, supported by a $17.6 million grant from the Cancer Prevention & Research Institute of Texas, builds upon promising results from their completed Phase 1 trial.
The dose optimization study will enroll up to 24 patients across four cohorts, evaluating multiple-dose regimens of REYOBIQ at the recommended Phase 2 dose of 44.1 mCi. The trial will be conducted at two Texas cancer centers: the University of Texas Health Science Center at San Antonio and the University of Texas Southwestern Medical Center.
The completed Phase 1 trial demonstrated encouraging results, including a 76% clinical benefit rate in neuroimaging results, with 29% achieving partial responses and 47% maintaining stable disease. Notably, 5 of 7 patients with over 80% reduction of LM tumor cells in CSF survived at least one year after initial treatment.
Plus Therapeutics (NASDAQ:PSTV) ha annunciato l'accordo con la FDA per avviare lo studio di ottimizzazione del dosaggio ReSPECT-LM per REYOBIQ鈩� (rhenium Re186 obisbemeda) nel trattamento delle metastasi leptomeningee (LM). Lo studio, supportato da una borsa di studio di 17,6 milioni di dollari dal Cancer Prevention & Research Institute of Texas, si basa sui risultati promettenti del loro trial di Fase 1 gi脿 completato.
Lo studio di ottimizzazione del dosaggio arruoler脿 fino a 24 pazienti suddivisi in quattro coorti, valutando schemi posologici multipli di REYOBIQ alla dose raccomandata per la Fase 2 di 44,1 mCi. Il trial si svolger脿 in due centri oncologici del Texas: l'University of Texas Health Science Center di San Antonio e l'University of Texas Southwestern Medical Center.
Il trial di Fase 1 completato ha mostrato risultati incoraggianti, con un tasso di beneficio clinico del 76% nei risultati neuroimmagini, di cui il 29% ha ottenuto risposte parziali e il 47% ha mantenuto una malattia stabile. In particolare, 5 su 7 pazienti con una riduzione superiore all'80% delle cellule tumorali LM nel liquido cerebrospinale sono sopravvissuti almeno un anno dopo il trattamento iniziale.
Plus Therapeutics (NASDAQ:PSTV) ha anunciado el acuerdo con la FDA para iniciar el ensayo de optimizaci贸n de dosis ReSPECT-LM para REYOBIQ鈩� (rhenium Re186 obisbemeda) en el tratamiento de las met谩stasis leptomen铆ngeas (LM). El estudio, respaldado por una subvenci贸n de 17.6 millones de d贸lares del Cancer Prevention & Research Institute of Texas, se basa en los prometedores resultados de su ensayo de Fase 1 ya completado.
El estudio de optimizaci贸n de dosis inscribir谩 a hasta 24 pacientes distribuidos en cuatro cohortes, evaluando m煤ltiples reg铆menes de dosis de REYOBIQ en la dosis recomendada para la Fase 2 de 44.1 mCi. El ensayo se llevar谩 a cabo en dos centros oncol贸gicos de Texas: el University of Texas Health Science Center en San Antonio y el University of Texas Southwestern Medical Center.
El ensayo de Fase 1 completado mostr贸 resultados alentadores, con una tasa de beneficio cl铆nico del 76% en los resultados de neuroimagen, con un 29% logrando respuestas parciales y un 47% manteniendo enfermedad estable. Notablemente, 5 de 7 pacientes con m谩s del 80% de reducci贸n de c茅lulas tumorales LM en el LCR sobrevivieron al menos un a帽o despu茅s del tratamiento inicial.
Plus Therapeutics (NASDAQ:PSTV)臧� REYOBIQ鈩�(rhenium Re186 obisbemeda)毳� 鞚挫毄頃� 雵岆鞝勳澊(Leptomeningeal Metastases, LM) 旃橂毳� 鞙勴暅 ReSPECT-LM 鞖╇焿 斓滌爜頇� 鞛勳儊鞁滍棙 臧滌嫓毳� FDA鞕� 頃╈潣頄堧嫟瓿� 氚滍憸頄堨姷雼堧嫟. 鞚� 鞛勳儊鞁滍棙鞚� 韰嶌偓鞀� 鞎� 鞓堧癌 氚� 鞐瓣惮靻�(Cancer Prevention & Research Institute of Texas)搿滊秬韯� 1,760毵� 雼煬鞚� 氤挫“旮�鞚� 歆�鞗愲皼鞎� 歆勴枆霅橂┌, 鞕勲霅� 1靸� 鞁滍棙鞚� 鞙犽頃� 瓴瓣臣毳� 旮半皹鞙茧 頃╇媹雼�.
鞖╇焿 斓滌爜頇� 鞐瓣惮電� 斓滊寑 24氇呾潣 頇橃瀽毳� 雱� 臧� 旖旐樃韸鸽 雮橂垊鞏�, 甓岇灔 2靸� 鞖╇焿鞚� 44.1 mCi鞚� REYOBIQ 雼ろ殞 韴棳 鞖旊矔鞚� 韽夑皜頃╇媹雼�. 鞚� 鞛勳儊鞁滍棙鞚� 韰嶌偓鞀れ潣 霊� 鞎� 靹柬劙鞚� University of Texas Health Science Center at San Antonio鞕� University of Texas Southwestern Medical Center鞐愳劀 歆勴枆霅╇媹雼�.
鞕勲霅� 1靸� 鞁滍棙鞐愳劀電� 鞁犼步鞓侅儊 瓴瓣臣鞐愳劀 76%鞚� 鞛勳儊鞝� 鞙犾澋毳�鞚� 氤挫榾鞙茧┌, 29%臧� 攵�攵� 氚橃潙鞚�, 47%電� 鞎堨爼霅� 氤戨硛鞚� 鞙犾頄堨姷雼堧嫟. 韸鬼瀳, 雵岇矙靾橃暋 雮� LM 膦呾枒 靹疙彫臧� 80% 鞚挫儊 臧愳唽頃� 7氇� 欷� 5氇�鞚� 齑堦赴 旃橂 頉� 斓滌唽 1雲� 鞚挫儊 靸濎〈頄堨姷雼堧嫟.
Plus Therapeutics (NASDAQ:PSTV) a annonc茅 un accord avec la FDA pour lancer l'essai d'optimisation de la dose ReSPECT-LM pour REYOBIQ鈩� (rh茅nium Re186 obisbemeda) dans le traitement des m茅tastases leptomening茅es (LM). Cet essai, soutenu par une subvention de 17,6 millions de dollars du Cancer Prevention & Research Institute of Texas, s'appuie sur les r茅sultats prometteurs de leur essai de Phase 1 achev茅.
L'茅tude d'optimisation de la dose recrutera jusqu'脿 24 patients r茅partis en quatre cohortes, 茅valuant plusieurs sch茅mas posologiques de REYOBIQ 脿 la dose recommand茅e pour la Phase 2 de 44,1 mCi. L'essai se d茅roulera dans deux centres de canc茅rologie du Texas : l'University of Texas Health Science Center 脿 San Antonio et l'University of Texas Southwestern Medical Center.
L'essai de Phase 1 termin茅 a montr茅 des r茅sultats encourageants, avec un taux de b茅n茅fice clinique de 76% dans les r茅sultats de neuroimagerie, dont 29% ont obtenu des r茅ponses partielles et 47% ont maintenu une maladie stable. Notamment, 5 des 7 patients ayant une r茅duction de plus de 80% des cellules tumorales LM dans le LCR ont surv茅cu au moins un an apr猫s le traitement initial.
Plus Therapeutics (NASDAQ:PSTV) hat die Einigung mit der FDA zur Einleitung der ReSPECT-LM Dosisoptimierungsstudie f眉r REYOBIQ鈩� (Rhenium Re186 obisbemeda) zur Behandlung von leptomeningealen Metastasen (LM) bekanntgegeben. Die Studie wird durch einen 17,6 Millionen Dollar Zuschuss des Cancer Prevention & Research Institute of Texas unterst眉tzt und baut auf vielversprechenden Ergebnissen der abgeschlossenen Phase-1-Studie auf.
Die Dosisoptimierungsstudie wird bis zu 24 Patienten in vier Kohorten einschlie脽en und verschiedene Mehrfachdosis-Regime von REYOBIQ bei der empfohlenen Phase-2-Dosis von 44,1 mCi evaluieren. Die Studie wird an zwei Krebszentren in Texas durchgef眉hrt: dem University of Texas Health Science Center in San Antonio und dem University of Texas Southwestern Medical Center.
Die abgeschlossene Phase-1-Studie zeigte vielversprechende Ergebnisse mit einer klinischen Ansprechrate von 76% in der Neuroimaging-Auswertung, wobei 29% partielle Remissionen und 47% stabile Erkrankungen erreichten. Bemerkenswert ist, dass 5 von 7 Patienten mit 眉ber 80% Reduktion der LM-Tumorzellen im Liquor mindestens ein Jahr nach der Erstbehandlung 眉berlebten.
- None.
- Grade 4 dose-limiting toxicities (thrombocytopenia) occurred in Cohorts 5 and 6 of Phase 1
- Trial initially limited to only two cancer centers, potentially affecting enrollment speed
- Multiple doses and longer treatment intervals may increase patient burden
Insights
PSTV advances REYOBIQ into dose optimization trial for leptomeningeal metastases after promising Phase 1 results, supported by $17.6M CPRIT grant.
Plus Therapeutics is making significant progress with REYOBIQ (rhenium Re186 obisbemeda) for leptomeningeal metastases (LM), a notoriously difficult-to-treat condition where cancer spreads to the membranes surrounding the brain and spinal cord. The company is moving forward with a dose optimization trial following promising results from their single-dose escalation study, where they observed a clinical benefit rate of 76% based on neuroimaging and 87% based on clinical examination.
The new trial aligns with the FDA's Project Optimus initiative, which emphasizes optimizing dosing regimens rather than simply identifying maximum tolerated doses. This approach is particularly crucial for radiotherapeutics where balancing efficacy and safety is delicate. The trial will enroll up to 24 patients across four cohorts with different dosing intervals (56, 28, and 14 days) to determine the optimal treatment schedule.
What's particularly notable is that the recommended Phase 2 dose (RP2D) of 44.1 mCi demonstrated remarkable properties in earlier testing. The radiotherapeutic remained in cerebrospinal fluid for at least 7 days and delivered an average absorbed dose of 253 Gy to the cranial subarachnoid space in the highest dose cohort. This prolonged presence is critical for treating LM, where cancer cells circulate throughout the cerebrospinal fluid.
The $
The pharmacodynamic data showing early apoptosis, immune activation, and T-cell activity suggest REYOBIQ may work through multiple mechanisms beyond direct radiation damage, potentially enhancing its therapeutic potential. Most impressively, 5 of 7 patients with over
Primary objective to determine optimal dosing schedule for a registrational trial
Trial builds on recommended Phase 2 dose determined in completed Phase 1 trial
Trial benefits from
HOUSTON, June 30, 2025 (GLOBE NEWSWIRE) -- (Nasdaq: ) (the 鈥淐ompany鈥�), a clinical-stage pharmaceutical company developing targeted radiotherapeutics with advanced platform technologies for central nervous system (CNS) cancers, today announces the initiation of the ReSPECT-LM dose optimization trial for REYOBIQTM (rhenium Re186 obisbemeda) for the treatment of leptomeningeal metastases (LM). The dose optimization trial follows encouraging results from the Company鈥檚 and is designed to evaluate multiple-dose regimens of REYOBIQ administered at defined intervals via intraventricular catheter (Ommaya reservoir).
鈥淎 safe and effective therapeutic to address the epidemic of CNS metastases and specifically leptomeningeal metastases is urgently needed,鈥� said Marc H. Hedrick, M.D., Plus Therapeutics President and Chief Executive Officer. 鈥淲e expect that optimizing the dosing regimen for REYOBIQ in this trial will provide data needed to design and support a follow-on registrational trial.鈥�
ReSPECT-LM Dose Optimization Trial Design
The study design is consistent with the , and aims to optimize treatment dosing for maximum efficacy and safety. The primary objectives of the trial include determining the safety and tolerability of multiple REYOBIQ doses administered via intraventricular catheter at defined intervals in patients with LM from any primary solid tumor cancer and to identify both the maximum tolerated dose and minimum effective dose.
Key additional elements of the trial design include:
- Enrollment of up to 24 patients, evaluating REYOBIQ administered at the recommended Phase 2 dose or R2PD of 44.1 mCi, fractionated across three dosing intervals, with up to six patients per cohort interval:
- Cohort 1: 56 days
- Cohort 2: 28 days
- Cohort 3a: 14 days
- Cohort 3b: 14 days (6 doses)
- The trial will evaluate both safety, pharmacokinetics/dosimetry, and select efficacy-related endpoints such as objective response rate (ORR), neurologic progression-free survival (PFS), overall survival (OS), changes in neurologic status
- Furthermore, the trial will analyze cerebrospinal fluid (CSF) tumor cell counts via Plus鈥� CNSide CSF assay platform, other pharmacodynamic markers, and compare these to standard CSF cytology
Because of the anticipated pace of enrollment, the trial is being limited initially to only two prestigious and high enrolling cancer centers, both in Texas鈥攖he University of Texas Health Science Center at San Antonio (UTHSCSA) and the University of Texas Southwestern Medical Center (UTSW) but may expand to more sites if needed.
The dose optimization study builds on promising results from the Company鈥檚 . Key highlights include:
- Cohort 4 dose (44.1 mCi) was determined to be the RP2D
- Pharmacodynamic and pharmacokinetic data showed that a single dose of REYOBIQ remained in the CSF for at least 7 days, and delivered up to an average absorbed dose of 253 Gy to the cranial subarachnoid space in Cohort 5
- Neuroimaging results showed a clinical benefit rate1 of
76% , with 5 of 17 patients (29% ) achieving partial responses and 8 (47% ) maintaining stable disease through Day 112 - Clinical examination showed a clinical benefit rate in
87% of evaluable patients, with 13 of 15 patients showing a partial response or stable disease based on physician assessment - No dose-limiting toxicities (DLTs) were observed in the first four cohorts; one Grade 4 DLT (thrombocytopenia) occurred in each of Cohorts 5 and 6
- Biologic signals of early apoptosis, innate immune activation, and increased T-cell activity by Day 28, as observed through RNA sequencing of LM cells
- 5 of 7 patients with over
80% reduction of LM tumor cells in CSF survived at least one year after initial treatment
The Company anticipates presenting these data and additional information from the completed single-dose escalation trial at the upcoming SNO/ASCO CNS Metastases Conference on August 14-16, 2025, in Baltimore, MD. The company will also request an End of Phase 1 Type B meeting with the FDA to align on the clinical development plan and the design of a potential registrational trial.
The ReSPECT-LM dose optimization trial benefits from a
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⒙�(rhenium Re186听辞产颈蝉产别尘别诲补)
REYOBIQ鈩� (rhenium Re186听辞产颈蝉产别尘别诲补) 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鈩� 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鈩� 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 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), recurrent glioblastoma (GBM), and pediatric brain cancer (PBC). 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 or contact .
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.
These statements include, without limitation, statements regarding the potential promise of REYOBIQ鈩�, expectations as to the Company鈥檚 future performance, including the next steps in developing the Company鈥檚 product candidates; the Company鈥檚 clinical trials, including statements regarding the timing and characteristics of the ReSPECT-LM single dose and multi-dose clinical trials; the continued evaluation of REYOBIQ鈩� including through evaluations in additional patient cohorts.
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 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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1 Clinical benefit rate defined as complete response + partial response + stable disease
FAQ
What is the recommended Phase 2 dose (R2PD) for REYOBIQ in the Plus Therapeutics (PSTV) trial?
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