Cellectar Biosciences Presented Compelling Data in Oral Session and Panel Discussions at the American Association for Cancer Research Special Conference on Discovery and Innovation in Pediatric Cancer
Cellectar Biosciences (NASDAQ: CLRB) presented promising interim data from its CLOVER-2 Phase 1b study of iopofosine I 131 at the AACR Special Conference on Pediatric Cancer. The study evaluated the drug's effectiveness in treating relapsed/refractory pediatric high-grade glioma (r/r pHGG).
Key findings include: Patients receiving minimum 55 mCi dose (n=7) showed average PFS of 5.4 months and OS of 8.6 months, significantly exceeding historical medians of 2.25 and 5.6 months respectively. Patients receiving four or more infusions (n=3) demonstrated improved outcomes with 8.1 months PFS and 11.5 months OS. Two notable case studies showed remarkable results, including a patient achieving 50% tumor reduction and survival beyond 18 months.
The treatment was well-tolerated with manageable side effects, primarily hematologic in nature, with no cardiovascular, renal, liver toxicities, or treatment-related deaths reported.
Cellectar Biosciences (NASDAQ: CLRB) ha presentato dati intermedi promettenti dallo studio CLOVER-2 di fase 1b su iopofosina I-131 durante la conferenza speciale AACR sul cancro pediatrico. lo studio ha valutato l’efficacia del farmaco nel trattamento del glioma pediatrico ad alto grado ricorrente/refrattario (r/r pHGG).
Rimasti chiave: i pazienti che hanno ricevuto una dose minima di 55 mCi (n=7) hanno una PFS media di 5,4 mesi e un OS di 8,6 mesi, superando significativamente le medie storiche di 2,25 e 5,6 mesi. I pazienti che hanno ricevuto quattro infusioni o più (n=3) hanno mostrato esiti migliori con 8,1 mesi di PFS e 11,5 mesi di OS. Due studi di caso notevoli hanno mostrato risultati eccezionali, tra cui un paziente che ha ottenuto una riduzione del tumore del 50% e una sopravvivenza superiore a 18 mesi.
Il trattamento è stato ben tollerato con effetti avversi gestibili, principalmente di natura ematologica, senza tossicità cardiovascolare, renale o epatica né decessi correlati al trattamento riportati.
Cellectar Biosciences (NASDAQ: CLRB) presentó datos interinos prometedores de CLOVER-2, un estudio de fase 1b de iopofosina I-131, en la Conferencia Especial de AACR sobre Cáncer Pediátrico. El estudio evaluó la eficacia del fármaco para tratar el glioma de alto grado pediátrico en recaída/refractario (r/r pHGG).
Hallazgos clave: los pacientes que recibieron una dosis mínima de 55 mCi (n=7) mostraron una media de PFS de 5,4 meses y OS de 8,6 meses, superando significativamente las medianas históricas de 2,25 y 5,6 meses. Los pacientes que recibieron cuatro infusiones o más (n=3) mostraron mejores resultados con 8,1 meses de PFS y 11,5 meses de OS. Dos estudios de caso notables mostraron resultados asombrosos, incluido un paciente que logró una reducción del tumor del 50% y una supervivencia superior a 18 meses.
El tratamiento se toleró bien, con efectos secundarios manejables, principalmente hematológicos, sin toxicidad cardiovascular, renal o hepática ni muertes relacionadas con el tratamiento.
Cellectar Biosciences (NASDAQ: CLRB)는 AACR 소아암 특별 학술대회에서 CLOVER-2 1상 2상 연구의 아이오포포신 I-131의 고무적인 중간 데이터를 발표했습니다. 이 연구는 재발/난치성 소아 고등성형 뇌종양(r/r pHGG)의 치료에 대한 약물의 효과를 평가했습니다.
주요 발견: 최소 55 mCi 용량(n=7)을 투여한 환자에서 평균 PFS 5.4개월, OS 8.6개월로, 과거 중앙값인 2.25개월 및 5.6개월보다 유의하게 높았습니다. 4회 이상 주사(n=3)를 받은 환자들은 8.1개월 PFS, 11.5개월 OS로 개선되었습니다. 두 건의 주목할 만한 사례 연구에서는 종양 감소 50%와 18개월 이상 생존을 달성한 환자를 포함해 놀라운 결과를 보여주었습니다.
치료는 혈액학적 부작용이 주를 이룬 관리 가능한 부작용과 함께 잘 견뎌졌으며, 심혈관, 신장, 간 독성이나 치료 관련 사망은 보고되지 않았습니다.
Cellectar Biosciences (NASDAQ: CLRB) a présenté des données intermédiaires prometteuses du CLOVER-2, une étude de phase 1b sur l’iopofosine I-131, lors de la conférence spéciale AACR sur le cancer pédiatrique. L’étude évaluait l’efficacité du médicament dans le traitement du gliome pédiatrique de haut grade en rechute/réfractaire (r/r pHGG).
Principales conclusions : les patients recevant une dose minimale de 55 mCi (n=7) ont une médiane de PFS de 5,4 mois et un OS de 8,6 mois, dépassant fortement les médianes historiques de 2,25 et 5,6 mois. Les patients ayant reçu quatre perfusions ou plus (n=3) ont montré des résultats améliorés avec 8,1 mois de PFS et 11,5 mois d’OS. Deux études de cas notables montrent des résultats remarquables, y compris un patient atteignant une réduction de la tumeur de 50 % et une survie de plus de 18 mois.
Le traitement a été bien toléré avec des effets secondaires gérables, principalement d’origine hématologique, sans toxicité cardiovasculaire, rénale ou hépatique, ni décès liés au traitement reportés.
Cellectar Biosciences (NASDAQ: CLRB) hat auf der AACR-Spezialkonferenz zu kindlicher Krebs vorbehaltlich vielversprechende Zwischendaten aus CLOVER-2 Phase-1b-Studie von Iopofosine I-131 präsentiert. Die Studie bewertete die Wirksamkeit des Medikaments bei der Behandlung von relapsed/refractory pädiatrischem Hochgrad-Gliom (r/r pHGG).
Wichtige Befunde: Patienten, die eine Mindestdosis von 55 mCi erhielten (n=7), zeigten eine mittlere PFS von 5,4 Monaten und OS von 8,6 Monaten, was deutlich über den historischen Medians von 2,25 bzw. 5,6 Monaten liegt. Patienten mit vier oder mehr Infusionen (n=3) zeigten verbesserte Ergebnisse mit 8,1 Monaten PFS und 11,5 Monaten OS. Zwei bemerkenswerte Fallstudien zeigten außergewöhnliche Ergebnisse, darunter ein Patient mit 50%-Tumorrückgang und einer Überlebensdauer von über 18 Monaten.
Die Behandlung wurde gut vertragen, mit handhabbaren Nebenwirkungen, hauptsächlich hämatologisch, ohne kardiovaskuläre, renale oder Lebertoxizitäten oder behandlungsbedingte Todesfälle.
شركة Cellectar Biosciences (بورصة ناسداك: CLRB) قدمت بيانات وسيطة واعدة من دراسة CLOVER-2 من المرحلة 1b لعقار iopofosine I-131 في المؤتمر الخاص لـ AACR حول سرطان الأطفال. درست الدراسة فاعلية الدواء في علاج الورم الدماغي عالي الدرجة عند الأطفال المتكرر/المقاوم (r/r pHGG).
النتائج الرئيسية: المرضى الذين تلقوا جرعة دنيا قدرها 55 mCi (عدد=7) أظهرت متوسط PFS قدره 5.4 أشهر وOS قدره 8.6 أشهر، وهو أعلى بشكل كبير من الوسيطات التاريخية البالغة 2.25 و5.6 أشهر. المرضى الذين تلقوا أربع حقن أو أكثر (عدد=3) أظهروا نتائج محسّنة مع 8.1 أشهر PFS و11.5 أشهر OS. حالتا حالة بارزتان أظهرتا نتائج رائعة، بما في ذلك مريض حقق تقلص الورم بنسبة 50% وبقاء على قيد الحياة لأكثر من 18 شهراً.
كان العلاج جيد التحمل مع آثار جانبية قابلة للإدارة، تتمثل أساساً في الدموية، دون سمّيات قلبية أو كلوية أو كبدية، ولا وفيات مرتبطة بالعلاج.
Cellectar Biosciences (NASDAQ: CLRB) 于AACR儿童癌症特别会议公布了CLOVER-2 Phase 1b 研究中Iopofosine I-131的有前景的中期数据。该研究评估药物治疗复发/难治性儿科高等级胶质瘤（r/r pHGG）的有效性。
关键发现包括：接受55 mCi 最低剂量的患者（n=7）显示 平均PFS为5.4个月、OS为8.6个月，显著高于历史中位数的 2.25个月和5.6个月。接受四次或以上输注的患者（n=3）显示 8.1个月PFS、11.5个月OS的改善结果。两个显著的病例研究显示了显著结果，其中一名患者实现了 肿瘤缩小50% 且生存期超过18个月。
治疗总体耐受良好，副作用以血液学为主，未出现心血管、肾脏或肝脏毒性，亦无治疗相关死亡报告。
- Significant improvement in survival metrics compared to historical data
- Two patients achieved objective response with tumor reduction
- Well-tolerated safety profile with manageable side effects
- FDA granted Rare Pediatric Drug and Orphan Drug Designations
- All evaluable patients experienced disease control
- Limited patient sample size (n=14) in the study
- Treatment caused hematologic adverse events (thrombocytopenia, neutropenia, anemia)
Insights
Cellectar's iopofosine I 131 shows promising survival extension in pediatric brain cancer patients with limited treatment options.
The interim data from Cellectar's Phase 1b CLOVER-2 study demonstrates meaningful clinical benefits for patients with relapsed/refractory pediatric high-grade glioma (r/r pHGG) – an aggressive brain cancer with devastatingly poor outcomes. Historically, these patients face median progression-free survival (PFS) of only
What's significant is that patients receiving at least 55 mCi total administered dose experienced substantially improved outcomes: average PFS of
Two case studies highlight iopofosine I 131's potential: a 25-year-old male with diffuse hemispheric glioma achieved greater than
The safety profile appears manageable, with adverse events primarily hematologic (thrombocytopenia, neutropenia, anemia) and notably absent of cardiovascular, renal, liver toxicities, peripheral neuropathy, or significant bleeding – suggesting precise tumor targeting with minimal off-target effects.
This data represents a potentially significant advance for pediatric brain cancer patients who currently have few effective treatment options. The FDA has already granted Rare Pediatric Drug and Orphan Drug Designations for this treatment, recognizing its potential importance.
Iopofosine I 131's interim data shows promising survival extension for pediatric brain cancer patients with few alternatives.
This interim data represents a potentially significant advancement in the treatment landscape for pediatric high-grade gliomas. The radioconjugate monotherapy appears to be delivering meaningful clinical benefit in a patient population with extremely limited options and poor prognosis.
From a development perspective, several aspects stand out. First, the dose-response relationship is becoming evident – patients receiving higher cumulative doses (minimum 55 mCi) showed better outcomes, and those receiving multiple dosing cycles demonstrated even more substantial benefits. This suggests optimal dosing strategies are emerging, critical for maximizing efficacy while maintaining safety.
The drug's selective targeting mechanism appears to be functioning as designed. The phospholipid ether delivery vehicle is successfully transporting the radioisotope preferentially to tumor sites, explaining why toxicity is largely confined to expected hematologic effects without significant off-target organ damage.
The interim data also validates the biomarker strategy of using RAPNO criteria to assess disease control, as it correlates with survival benefits. This provides important surrogate endpoints that could potentially support regulatory discussions.
With FDA Rare Pediatric Drug and Orphan Drug Designations already secured, Cellectar has positioned iopofosine I 131 for potential expedited development pathways. Given the dramatic unmet need in pediatric brain cancers and the encouraging efficacy signals in heavily pretreated patients (one case study patient had eight prior therapies), this program could potentially move quickly through clinical development if final results confirm these interim findings.
CLOVER-2 Phase 1 Clinical Study Evaluating Iopofosine I 131 in Relapsed/Refractory Pediatric High-Grade Glioma Patients Showed Extended Progression-Free Survival and Overall Survival
FLORHAM PARK, N.J., Sept. 30, 2025 (GLOBE NEWSWIRE) -- Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery and development of drugs for the treatment of cancer, today announced that Jarrod Longcor, chief operating officer of Cellectar, delivered an oral presentation followed by a 55-minute panel discussion with other experts in the field at the American Association for Cancer Research (AACR) Special Conference on Pediatric Cancer that took place September 25-28 in Boston, Massachusetts. The oral presentation highlighted interim data from the Phase 1b dose and regimen optimization study of iopofosine I 131 in inoperable relapsed or refractory pediatric high-grade glioma (r/r pHGG).
Iopofosine I 131 is a potential first-in-class, novel cancer targeting agent utilizing a phospholipid ether as a radioconjugate monotherapy. The U.S. Food and Drug Administration (FDA) previously granted Rare Pediatric Drug and Orphan Drug Designations for iopofosine I 131 for the treatment of pHGG.
“Presenting these promising interim results at AACR’s Special Conference on Pediatric Cancer before an audience of pediatric oncologists and other researchers in the field was a meaningful milestone for Cellectar,” said James Caruso, Cellectar’s president and CEO. “The data from our CLOVER-2 study demonstrate encouraging signs of tumor volume reduction, disease control and extended survival in children and young adults with relapsed or refractory high-grade gliomas—an area of devastating unmet need. We remain committed to advancing iopofosine I 131 as a targeted radiotherapeutic option for patients with few alternatives.”
Pediatric high-grade gliomas are a collection of aggressive tumors affecting the brain and central nervous system. The patients enrolled in CLOVER-2 with pHGG (n=14) were diagnosed with diffuse midline gliomas (DMG), ependymomas, diffuse intrinsic pontine gliomas (DIPG), diffuse hemispheric gliomas (DHG) and anaplastic ependymomas. As reported in the literature, median progression free survival (PFS) and overall survival (OS) for patients with r/r pHGG is poor; approximately 2.25 months and 5.6 months, respectively.
The interim data were delivered by Mr. Longcor in an oral presentation titled, “Precision Radiotherapy for Incurable Brain Tumors: Phase 1b Dose & Regimen Optimization Study of Iopofosine I 131 in Inoperable Relapsed or Refractory Pediatric High-Grade Glioma, Interim Data Assessment.”
All patients receiving a minimum of 55 mCi total administered dose (n=7) and evaluable (n=6) experienced an average of 5.4 months of PFS and 8.6 months of OS, ongoing. All patients experienced disease control, which according to the committee for the Response Assessment in Pediatric Neuro-Oncology (RAPNO) does correlate with survival benefit. Three patients who received additional dosing cycles (a minimum of four total infusions) had an average PFS of 8.1 months and an OS of 11.5 months (ranging from 4.9 to 14.9 months), ongoing, with two achieving an objective response (ORR).
Two case studies were highlighted in the oral presentation. Case Study 1 showed a 25-year-old male with diffuse hemispheric glioma with the H3 G34R/V mutation who had three prior therapies and who received a total administered dose of 126.6mCi of iopofosine I 131 over four doses (40mCi/m2/dose) had his target lesion reduced by more than
Case Study 2 showed a 15-year-old female with ependymoma who had eight prior therapies and who received a total administered dose of 58.9mCi of iopofosine I 131 over four doses (20mCi/m2/dose) had her target lesion reduced from 252mm2 to approximately 141mm2. This patient had PFS of 11.2 months and her ongoing survival was greater than 17 months as of July 22, 2025.
Iopofosine I 131 was well tolerated and its toxicity profile was consistent with the Company's previously reported safety data. Importantly, patients in the study treated with iopofosine I 131 did not experience any cardiovascular, renal, or liver toxicities, peripheral neuropathy or significant bleeding. The safety profile was consistent with selective targeting of tumor sites with clinically negligible off-target effect outside the hematologic system. The most frequently reported treatment-emergent adverse events were hematologic in nature (thrombocytopenia, neutropenia and anemia) and were predictable and manageable. No treatment-related deaths were reported.
The complete presentation can be accessed on the Company’s website here.
About Pediatric High-Grade Gliomas
Pediatric high-grade gliomas are a collection of aggressive tumors affecting the brain and central nervous system. The patients enrolled in CLOVER-2 with pHGG (n=14) were diagnosed with diffuse midline gliomas (DMG), ependymomas, diffuse intrinsic pontine gliomas (DIPG), diffuse hemispheric gliomas (DHG) and anaplastic ependymomas. As reported in the literature, median progression free survival (PFS) and overall survival (OS) for patients with relapsed pHGG is poor; approximately 2.25 months and 5.6 months, respectively. While MRI measures of tumor volume change can be helpful and are used as a surrogate in clinical trials, they often fail to predict survival.
About the CLOVER-2 Trial
The ongoing Phase 1b trial of iopofosine I 131 consists of children, adolescents and young adults with r/r pHGG at multiple sites in the United States and Canada. The study is designed to evaluate the safety and tolerability of iopofosine I 131 in two dosing cohorts, one cohort receiving two doses at 20mCi/m2 each separated by 14 days for two cycles with a third optional cycle. Patients in the second cohort will receive 10 mCi/m2 each, separated by 14 days for three cycles with a fourth optional cycle. The study will also determine therapeutic activity defined as progression-free survival (PFS) and overall survival, antitumor activity defined as the reduction in tumor volume and identify the recommended Phase 2/3 dose of iopofosine I 131 in children, adolescents and young adults with r/r pHGG. The Clover 2 study is active but not enrolling at this time.
About Cellectar Biosciences, Inc.
Cellectar Biosciences is a late-stage clinical biopharmaceutical company focused on the discovery and development of proprietary drugs for the treatment of cancer, independently and through research and development collaborations. The company’s core objective is to leverage its proprietary Phospholipid Drug Conjugate™ (PDC) delivery platform to develop the next-generation of cancer cell-targeting treatments, delivering improved efficacy and better safety as a result of fewer off-target effects.
The company’s product pipeline includes its lead assets: iopofosine I 131, a PDC designed to provide targeted delivery of iodine-131 (radioisotope); CLR 121225, an actinium-225 based program being targeted to several solid tumors with significant unmet need, such as pancreatic cancer; and CLR 121125, an iodine-125 Auger-emitting program targeted in other solid tumors, such as triple negative breast, lung and colorectal, as well as proprietary preclinical PDC chemotherapeutic programs and multiple partnered PDC assets.
In addition, iopofosine I 131 has been studied in Phase 2b trials for relapsed or refractory multiple myeloma (MM) and central nervous system (CNS) lymphoma, and the CLOVER-2 Phase 1b study, targeting pediatric patients with high-grade gliomas, for which Cellectar is eligible to receive a Pediatric Review Voucher from the FDA upon approval. The FDA has also granted iopofosine I 131 six Orphan Drug, four Rare Pediatric Drug and two Fast Track Designations for various cancer indications.
For more information, please visit www.cellectar.com or join the conversation by liking and following us on the company’s social media channels: X, LinkedIn, and Facebook.
Forward Looking Statements Disclaimer
This news release contains forward-looking statements. You can identify these statements by our use of words such as "may," "expect," "believe," "anticipate," "intend," "could," "estimate," "continue," "plans," or their negatives or cognates. These statements are only estimates and predictions and are subject to known and unknown risks and uncertainties that may cause actual future experience and results to differ materially from the statements made. These statements are based on our current beliefs and expectations as to such future outcomes. Drug discovery and development involve a high degree of risk. Factors that might cause such a material difference include, among others, uncertainties related to the FDA and EMA regulatory pathways, ability to execute strategic alternatives, identify suitable collaborators, partners, licensees or purchasers for our product candidates and, if we are able to do so, to enter into binding agreements with regard to any of the foregoing, or to raise additional capital to support our operations, or our ability to fund our operations if we are unsuccessful with any of the foregoing. A complete description of risks and uncertainties related to our business is contained in our periodic reports filed with the Securities and Exchange Commission including our Form 10-K for the year ended December 31, 2024, and our Form 10-Q for the quarterly period ending June 30, 2025. These forward-looking statements are made only as of the date hereof, and we disclaim any obligation to update any such forward-looking statements.
INVESTORS:
Anne Marie Fields
Precision AQ
212-362-1200
annemarie.fields@precisionaq.com
FAQ
What were the key results from Cellectar's CLOVER-2 Phase 1b study of iopofosine I 131?
How does iopofosine I 131 compare to historical survival rates in pediatric high-grade glioma?
What side effects were reported in the Cellectar CLRB clinical trial?
What regulatory designations has CLRB's iopofosine I 131 received from the FDA?
What was the most significant tumor reduction reported in Cellectar's CLOVER-2 study?
