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Soffietti, Riccardo

https://orcid.org/0000-0002-9204-7038

Mayo Clinic

Candiolo Cancer Institute

Citations 12

STELLAR: Phase III, Randomized, Open-Label Study of Eflornithine Plus Lomustine Versus Lomustine Alone in Patients With Recurrent Grade 3 Astrocytoma
Colman, Howard , Lombardi, Giuseppe , Wong, Eric T. , Walbert, Tobias , Lassman, Andrew B. , Peereboom, David M. , Kizilbash, Sani H. , Matsuoka, Carlos Kamiya , Pitz, Marshall , Desjardins, Annick , Kumthekar, Priya , Mason, Warren , Pellerino, Alessia , Butowski, Nicholas , Hamza, Mohamed A. , Lallana, Enrico C., Uhlmann, Erik J. , Welsh, Liam , Wen, Patrick Y. , Dietrich, Jörg , Wang, Chao , Levin, Victor A. , Lassman, Andrew B , Peereboom, David M , Kizilbash, Sani H , Kamiya-Matsuoka, Carlos , Pitz, Marshall W , Strowd, Roy E , Desjardins, Annick , Kumthekar, Priya , Mason, Warren , Pellerino, Alessia , Soffietti, Riccardo , Butowski, Nicholas A , Forsyth, Peter A , Hamza, Mohamed A , Hau, Peter , Nabors, Louis Burt , Uhlmann, Erik J , Welsh, Liam C , Wen, Patrick Yung , Dietrich, Jorg , Wang, Chao , Levin, Victor A , Colman, Howard , Eoli, Marica , Strowd, Roy E. , Soffietti, Riccardo , Hau, Peter , Nabors, Burt , Piccioni, David Eric , Lombardi, G

Journal of Clinical Oncology | December 1, 2025 | Volume: 44 | Issue: 8 | Pages: 641-652

10.1200/jco-25-01204 Get It

PURPOSE STELLAR (ClinicalTrials.gov identifier: NCT02796261 ) was a phase III, randomized, open-label trial of eflornithine + lomustine versus lomustine monotherapy in patients with recurrent grade 3 astrocytoma. METHODS At trial initiation, eligibility criteria included: age ≥18 years, anaplastic astrocytoma (2016 WHO CNS Tumor classification [WHO CNS4]), first recurrence ≥6 months after radiation and temozolomide (TMZ), Karnofsky performance status ≥70, and no imaging findings consistent with grade 4 glioblastoma. Random assignment (1:1) was stratified by isocitrate dehydrogenase ( IDH ) mutation, age, resection extent, and geography. Patients received eflornithine (2.8 g/m 2 orally, every 8 hours [2 weeks on, 1 week off]) + lomustine (90 mg/m 2 orally, once every 6 weeks), or lomustine monotherapy (110 mg/m 2 once every 6 weeks). The primary end point was overall survival (OS). RESULTS Among 343 patients randomly assigned across 74 sites in eight countries, there was no difference in survival between eflornithine + lomustine and lomustine monotherapy (median OS 23.4 v 20.3 months, hazard ratio [HR], 0.94). Following changes in classification and grading in the 2021 WHO CNS5, a subset analysis of patients with IDH- mutant, grade 3 astrocytoma (n = 196), defined in 2024, before unblinding, showed clinically meaningful improvements in median OS with eflornithine + lomustine versus lomustine monotherapy (34.9 v 23.5 months, HR, 0.64) and median progression-free survival (PFS, 15.8 v 7.2 months, HR, 0.57). No differences were observed among patients with CNS grade 4 disease. Grade ≥3 treatment-emergent adverse events of relevance were related to reversible myelosuppression (eflornithine + lomustine 42% v lomustine monotherapy 29% of patients) and hearing impairment (24% v 0%). No new safety signals were identified. CONCLUSION Clinically meaningful improvements were observed; eflornithine + lomustine doubled PFS and improved OS in patients with recurrent IDH -mutant, grade 3 astrocytoma, but not grade 4 tumors, after prior radiotherapy and TMZ, consistent with its cytostatic mechanism of action.
CTNI-58. UPDATED RESULTS OF PHASE 3 STELLAR TRIAL: EFLORNITHINE IMPROVES OVERALL SURVIVAL AND BLINDED INDEPENDENT CENTRAL REVIEW DETERMINED PROGRESSION FREE SURVIVAL IN PATIENTS WITH RECURRENT WHO 2021 GRADE 3 IDH-MUTANT ASTROCYTOMA
Colman, Howard , Walbert, Tobias , Lassman, Andrew B. , Kizilbash, Sani H. , Kamiya-Matsuoka, Carlos, Pitz, Marshall , Desjardins, Annick , Kumthekar, Priya , Mason, Warren, Butowski, Nicholas , Forsyth, Peter, Hamza, Mohamed A. , Lallana, Enrico C., Uhlmann, Erik J. , Welsh, Liam , Wen, Patrick Y. , Dietrich, Jörg , Levin, Victor A. , Kizilbash, Sani H , Colman, Howard , Lombardi, Giuseppe , Wong, Eric T. , Eoli, Marica , Peereboom, David M. , Strowd, Roy E. , Pellerino, Alessia , Soffietti, Riccardo , Hau, Peter , Nabors, Burt , Piccioni, David Eric , Wen, Patrick Yung

Neuro-Oncology | November 11, 2025 | Volume: 27 | Issue: Supplement_5 | Pages: v139-v140

10.1093/neuonc/noaf201.0554 Get It

Abstract BACKGROUND STELLAR was a phase III randomized, open-label trial of eflornithine (ornithine decarboxylase inhibitor) with lomustine versus lomustine alone in patients with recurrent anaplastic astrocytoma (AA). We previously reported an overall survival (OS) and progression free survival (PFS) of the combination in the patients with grade 3 IDH-mutant astrocytoma. Here we report updated OS and PFS outcomes based on additional molecular classification and blinded independent central review (BICR). METHOD Eligibility included: age ≥ 18 years, AA (2016 WHO criteria) with first recurrence ≥ 6 months after radiation, KPS ≥ 70, and no imaging findings consistent with grade 4 glioblastoma. Patients received eflornithine (2.8 g/m2 TID Q 2/3 weeks) with lomustine (90 mg/m2 Q 6 weeks) (Arm A) or lomustine alone (110 mg/m2 Q 6 weeks) (Arm B). Primary endpoint was OS. RESULTS Updated molecular data resulted in re-classification of the 343 AA patients enrolled into 3 WHO 2021 defined tumor subtypes, 196 tumors were IDHmut, CDKN2A/B intact, consistent with diagnosis of astrocytoma, IDHmut, WHO grade 3, 33 tumors had CDKN2A/B loss consistent with astrocytoma, IDHmut, WHO grade 4, 106 tumors were IDHwt consistent with diagnosis of glioblastoma, IDHwt, WHO grade 4. Updated results strengthen initial conclusion that eflornithine plus lomustine resulted in significant survival benefit in the astrocytoma, IDHmut, WHO grade 3 group (mOS 34.9 vs, 23.5 months, HR = 0.64, stratified log rank p =0.0136). PFS with eflornithine was also improved (15.8 vs, 7.2 months, HR = 0.57, stratified log rank p =0.0113). BICR demonstrated a high correlation between investigator and centrally determined PFS (p=0.0305), and high correlation between OS and PFS (p=.0001). CONCLUSION The clinically meaningful OS and PFS benefits observed with eflornithine in the molecularly defined 2021 WHO CNS grade 3 astrocytomas is further confirmed and expanded based on additional molecular classification and BICR of PFS.
P16.02.B DISPARITIES IN TRIAL ACCESS FOR GLIOMA PATIENTS: COMPARISON ACROSS SELECTED EUROPEAN COUNTRIES
Ser, Merve Hazal , Soffietti, Riccardo

Neuro-Oncology | October 3, 2025 | Volume: 27 | Issue: Supplement_3 | Pages: iii152-iii153

10.1093/neuonc/noaf193.514 Get It

Abstract BACKGROUND Gliomas are rare and aggressive CNS tumors with limited survival, making clinical trial (CT) participation indispensable, particularly in progressive cases. Cross-national disparities in glioma CT access remain underexplored. This study investigates temporal trends and socioeconomic correlates of glioma CT activity across eight European countries, using lung cancer trials as a benchmark. MATERIAL AND METHODS Glioma CTs registered after 2004 and conducted in France, Germany, Italy, Denmark, Poland, Hungary, Greece, or Turkey were extracted from ClinicalTrials.gov. A comparable lung cancer dataset was created. National-level data on population, gross national income (GNI) per capita, human development index (HDI), and cancer incidence were obtained from public sources. Trial access was defined as active CTs per estimated annual new cases. RESULTS Of 3,292 glioma CTs globally, 640 involved at least one target country. France (n=287), Germany (n=192), Italy (n=151), and Denmark (n=61) hosted the most; Turkey (n=5), Hungary (n=13), Greece (n=10), and Poland (n=26) contributed minimally. Over time, France, Germany and Italy showed significant upward trends in glioma CT activity (p < 0.05). Denmark, despite lower absolute numbers, showed strong growth relative to population. Turkey remained the least active participant, with no significant increase in glioma trial activity. When adjusted for estimated glioma cases, Denmark had the highest trial access, followed by France and Germany. Trial access positively correlated with GNI per capita (ρ = 0.76, p = 0.028) and moderately with HDI (ρ = 0.69, p = 0.058). In contrast, lung cancer trials were more abundant and equitably distributed (p = 0.0078), without significant correlation with national socioeconomic indicators (ρ =0.14, p=0.7 gor GNI per capita and ρ =0.19 p=0.7 for HDI). Despite having similar or lower GDP per capita compared to other countries in the analysis, Poland and Hungary showed substantially higher lung cancer trial access than glioma trial access, highlighting the underrepresentation of glioma research in resource-limited settings. Notably, Turkey exhibited the lowest glioma CT access (0.0010 per patient), despite a moderate volume of lung cancer trials. CONCLUSION Glioma CT access varies widely across Europe and is closely tied to GNI and HDI, unlike lung cancer trials, which are more equitably distributed. These disparities may relate to differences in the availability of trained neuro-oncology professionals and structured care systems, warranting further study. Targeted policy efforts are needed to improve access and inclusion in glioma research across all regions.
Preanalytical variables and analytes in liquid biopsy approach for brain tumors: A comprehensive review and recommendations from the RANO Group and the Brain Liquid Biopsy Consortium
Bettegowda, Chetan , Noushmehr, Houtan , Affinito, Alessandra , Ahluwalia, Manmeet S. , Ansorge, Olaf , Ayasoufi, Katayoun , Bagley, Stephen , Barnholtz‐Sloan, Jill S. , Brandsma, Dieta , Brodie, Chaya , Castro, Ana Valeria , Chang, Susan M. , Daher, Ahmad , Datta, Vineet , French, Pim J. , Golebiewska, Anna , Holdhoff, Matthias , LeBlang, Suzanne , Melin, Beatrice , Moulière, Florent , O’Leary, Claire , Robinson, Stephen , Sol, Nik , Vogelbaum, Michael A. , Walbert, Tobias , Watts, Colin , Wen, Patrick Y. , Wykes, Victoria , Yip, Stephen , Short, Susan , Barnholtz-Sloan, Jill S , Best, Myron , Brandsma, Dieta , Brüning-Richardson, Anke , Chang, Susan Marina , Condorelli, Gerolama , Daher, Ahmad , de Groot, John , French, Pim J , Galanis, Evanthia , Golebiewska, Anna , Hamerlik, Petra , Hanemann, C Oliver , Holdhoff, Matthias , Huse, Jason T. , Khasraw, Mustafa , LeBlang, Suzanne , Melin, Beatrice , Rominiyi, Ola , Roncaroli, F , Rudà, Roberta , Sol, Nik , van den Bent, Martin J , Walbert, Tobias , Watts, Colin , Weiss, Tobias , Weller, Michael , Wykes, Victoria , Yip, Stephen , Short, Susan C , Soffietti, Riccardo , Noushmehr, Houtan , Ayasoufi, Katayoun , Ahluwalia, Manmeet S , Bettegowda, Chetan , Groot, John de , Galanis, Evanthia , Hamerlik, Petra , Hanemann, C. Oliver , Khasraw, Mustafa , Rak, Janusz , Ray, Amitava, Roncaroli, Federico , Seoane, Joan , Bent, Martin J. van den , Wen, Patrick Yung , Soffietti, Riccardo

Neuro-Oncology | June 16, 2025 | Volume: 27 | Issue: 10 | Pages: 2496-2513

10.1093/neuonc/noaf140 Get It

Abstract This review explores the pivotal role of preanalytical variables in bringing liquid biopsy approaches into the clinic for brain tumors. Preanalytical variables encompass a range of critical issues, from blood sample collection and handling to the impact of tumor heterogeneity and patient-specific factors. These variables introduce challenges such as false positives, false negatives, and variability in the analysis of tumor signals, which can hinder the diagnostic and prognostic utility of liquid biopsies. Understanding the nuances of preanalytical variables is essential for the successful implementation of liquid biopsy in clinical settings. This paper delves into strategies aimed at mitigating the influence of preanalytical variables by emphasizing the importance of standardized sample collection protocols, optimized sample processing and storage, quality control measures, and the integration of multiple liquid biopsy modalities.
LTBK-01. PHASE 3 STELLAR STUDY SHOWS EFLORNITHINE IMPROVES OVERALL SURVIVAL (OS) AND PROGRESSION FREE SURVIVAL (PFS) IN PATIENTS WITH RECURRENT 2021 WHO ASTROCYTOMA, IDH-MUTANT GRADE 3
Colman, Howard , Walbert, Tobias , Lassman, Andrew B. , Kizilbash, Sani H. , Kamiya-Matsuoka, Carlos, Pitz, Marshall , Desjardins, Annick , Kumthekar, Priya , Mason, Warren, Butowski, Nicholas , Forsyth, Peter, Hamza, Mohamed A. , Lallana, Enrico C., Uhlmann, Erik J. , Welsh, Liam , Wen, Patrick Y. , Dietrich, Jörg , Levin, Victor A. , Kizilbash, Sani H , Colman, Howard , Lombardi, Giuseppe , Wong, Eric T. , Eoli, Marica , Peereboom, David M. , Strowd, Roy E. , Pellerino, Alessia , Soffietti, Riccardo , Hau, Peter , Nabors, Burt , Piccioni, David Eric , Wen, Patrick Yung

Neuro-Oncology | November 22, 2024 | Volume: 26 | Issue: Supplement_8 | Pages: viii1-viii1

10.1093/neuonc/noae165.1301 Get It

Abstract BACKGROUND Recurrent anaplastic astrocytoma (AA), a grade 3 brain cancer, remains an unmet medical need. STELLAR was a phase III randomized, open-label trial of eflornithine (ornithine decarboxylase inhibitor) with lomustine versus lomustine alone, originally for patients with recurrent AA. However, as the WHO definition of AA evolved during trial conduct (e.g., excluding IDH wild-type disease), we determined results in both the original ITT population and by revised molecularly defined WHO 2021 diagnoses in pre-planned analyses. METHOD Key eligibility: age ≥ 18, AA (2016 WHO criteria), first recurrence ≥ 6 months after radiation and temozolomide, KPS ≥ 70, no imaging findings consistent with grade 4 glioblastoma. Stratification: IDH, age, resection extent, and geography. Patients were randomized to Arm A: eflornithine (2.8 g/m2 TID Q 2/3 weeks) with lomustine (90 mg/m2 Q 6 weeks) or Arm B: lomustine (110 mg/m2 Q 6 weeks). Primary endpoint was OS. The pre-specified hazard ratio (HR) goal was 0.667 based on projected median OS (mOS) increase to 18 months from 12 months. RESULTS 343 pts (172/171 Arms A/B) were randomized (105 sites, 8 countries). ITT analysis found no difference between arms (mOS 23.4 vs. 20.3 months, HR = 0.94). However, a pre-specified subset analysis in IDH mutant, 2021 WHO-defined grade 3 astrocytoma (n=194), showed significant improvement with eflornithine (mOS 34.9 vs. 23.5 months, HR = 0.64, log rank p = 0.016) and PFS (15.8 vs. 7.2 months, HR = 0.58, log rank p = 0.015). No difference was observed in the IDH wild-type subset. AEs were consistent with historic data. CONCLUSION There was no difference in OS between arms in the ITT analysis. However, medically meaningful and statistically significant OS and PFS benefits were observed with eflornithine in the pre-planned analysis of patients with molecularly defined 2021 WHO CNS grade 3 astrocytoma.
Challenges, limitations, and pitfalls of PET and advanced MRI in patients with brain tumors: A report of the PET/RANO group
Vollmuth, Philipp, Lohmann, Philipp , Smits, Marion , Veronesi, Michael C. , Albert, Nathalie L. , Hutterer, Markus , Vogelbaum, Michael A. , Wen, Patrick Y. , Galldiks, Norbert , Lohmann, Philipp , Smits, Marion , Soffietti, Riccardo , Weller, Michael , Kaufmann, Timothy J. , Vollmuth, Philipp, Langen, Karl‐Josef , Rudà, Roberta , Hattingen, Elke , Law, Ian G. , Soffietti, Riccardo , Wen, Patrick Yung , Tonn, Joerg-Christian

Neuro-Oncology | March 11, 2024 | Volume: 26 | Issue: 7 | Pages: 1181-1194

10.1093/neuonc/noae049 Get It

Abstract Brain tumor diagnostics have significantly evolved with the use of positron emission tomography (PET) and advanced magnetic resonance imaging (MRI) techniques. In addition to anatomical MRI, these modalities may provide valuable information for several clinical applications such as differential diagnosis, delineation of tumor extent, prognostication, differentiation between tumor relapse and treatment-related changes, and the evaluation of response to anticancer therapy. In particular, joint recommendations of the Response Assessment in Neuro-Oncology (RANO) Group, the European Association of Neuro-oncology, and major European and American Nuclear Medicine societies highlighted that the additional clinical value of radiolabeled amino acids compared to anatomical MRI alone is outstanding and that its widespread clinical use should be supported. For advanced MRI and its steadily increasing use in clinical practice, the Standardization Subcommittee of the Jumpstarting Brain Tumor Drug Development Coalition provided more recently an updated acquisition protocol for the widely used dynamic susceptibility contrast perfusion MRI. Besides amino acid PET and perfusion MRI, other PET tracers and advanced MRI techniques (e.g. MR spectroscopy) are of considerable clinical interest and are increasingly integrated into everyday clinical practice. Nevertheless, these modalities have shortcomings which should be considered in clinical routine. This comprehensive review provides an overview of potential challenges, limitations, and pitfalls associated with PET imaging and advanced MRI techniques in patients with gliomas or brain metastases. Despite these issues, PET imaging and advanced MRI techniques continue to play an indispensable role in brain tumor management. Acknowledging and mitigating these challenges through interdisciplinary collaboration, standardized protocols, and continuous innovation will further enhance the utility of these modalities in guiding optimal patient care.
The Neurologic Assessment in Neuro-Oncology (NANO) Scale: A Tool to Assess Neurologic Function for Integration in the Radiologic Assessment in Neuro-Oncology (RANO) Criteria (S22.005)
Nayak, Lakshmi , Wen, Patrick Y. , Chamberlain, Marc C. , MacDonald, David , Perry, James , Jaeckle, Kurt A. , Reardon, David A. , DeAngelis, Lisa M. , Wen, Patrick Yung , Brandes, Alba Ariela , Soffietti, Riccardo , Lin, Nancy U. , Peereboom, David M. , Galanis, Evanthia , Mehta, Minesh P. , Stupp, Roger , Bent, Martin J. van den

Neurology | December 7, 2023 | Volume: 82 | Issue: 10_supplement | Pages: No page available

10.1212/wnl.82.10_supplement.s22.005 Get It

Brain metastases: A Society for Neuro-Oncology (SNO) consensus review on current management and future directions
Aizer, Ayal A. , Lamba, Nayan , Ahluwalia, Manmeet S. , Aldape, Kenneth , Boire, Adrienne , Brown, Paul D. , Camidge, D. Ross , Chiang, Veronica , Davies, Michael A. , Hu, Leland , Huang, Raymond Y. , Kumthekar, Priya , Lam, Keng , Lee, Eudocia Q. , Parsons, Michael , Reardon, David A. , Sheehan, Jason P. , Tawbi, Hussein A. , Weller, Michael , Wen, Patrick Y. , Kaufmann, Timothy, Kumthekar, Priya , Parsons, Michael W , Soffietti, Riccardo , Tawbi, Hussein , Weller, Michael , Ahluwalia, Manmeet S , Huang, Raymond , Brastianos, Priscilla K. , Kaufmann, Timothy J. , Lin, Nancy U. , Mehta, Minesh P. , Soffietti, Riccardo , Wen, Patrick Yung

Neuro-Oncology | May 3, 2022 | Volume: 24 | Issue: 10 | Pages: 1613-1646

10.1093/neuonc/noac118 Get It

Abstract Brain metastases occur commonly in patients with advanced solid malignancies. Yet, less is known about brain metastases than cancer-related entities of similar incidence. Advances in oncologic care have heightened the importance of intracranial management. Here, in this consensus review supported by the Society for Neuro-Oncology (SNO), we review the landscape of brain metastases with particular attention to management approaches and ongoing efforts with potential to shape future paradigms of care. Each coauthor carried an area of expertise within the field of brain metastases and initially composed, edited, or reviewed their specific subsection of interest. After each subsection was accordingly written, multiple drafts of the manuscript were circulated to the entire list of authors for group discussion and feedback. The hope is that the these consensus guidelines will accelerate progress in the understanding and management of patients with brain metastases, and highlight key areas in need of further exploration that will lead to dedicated trials and other research investigations designed to advance the field.
Liquid biopsy in gliomas: A RANO review and proposals for clinical applications
Mellinghoff, Ingo K. , Warren, Katherine E. , Ahluwalia, Manmeet S. , Galanis, Evanthia , Jaeckle, Kurt A. , Seoane, Joan , Thon, Niklas , Umemura, Yoshie , Weller, Michael , Bent, Martin J. van den , Vogelbaum, Michael A. , Chang, Susan M. , Wen, Patrick Y. , Soffietti, Riccardo , Galanis, Evanthia , Weller, Michael , van den Bent, Martin J , Umemura, Yoshie , Ahluwalia, Manmeet S , Mellinghoff, Ingo K , Soffietti, Riccardo , Bettegowda, Chetan , Groot, John de , Gilbert, Mark R. , Rhun, Émilie Le , Rudà, Roberta , Chang, Susan Marina , Wen, Patrick Yung

Neuro-Oncology | January 5, 2022 | Volume: 24 | Issue: 6 | Pages: 855-871

10.1093/neuonc/noac004 Get It

Abstract Background There is an extensive literature highlighting the utility of blood-based liquid biopsies in several extracranial tumors for diagnosis and monitoring. Methods The RANO (Response Assessment in Neuro-Oncology) group developed a multidisciplinary international Task Force to review the English literature on liquid biopsy in gliomas focusing on the most frequently used techniques, that is circulating tumor DNA, circulating tumor cells, and extracellular vesicles in blood and CSF. Results ctDNA has a higher sensitivity and capacity to represent the spatial and temporal heterogeneity in comparison to circulating tumor cells. Exosomes have the advantages to cross an intact blood-brain barrier and carry also RNA, miRNA, and proteins. Several clinical applications of liquid biopsies are suggested: to establish a diagnosis when tissue is not available, monitor the residual disease after surgery, distinguish progression from pseudoprogression, and predict the outcome. Conclusions There is a need for standardization of biofluid collection, choice of an analyte, and detection strategies along with rigorous testing in future clinical trials to validate findings and enable entry into clinical practice.
Phase 0 and window of opportunity clinical trial design in neuro-oncology: a RANO review
Vogelbaum, Michael A. , Krivosheya, Daria, Borghei‐Razavi, Hamid , Sanai, Nader , Weller, Michael , Wick, Wolfgang , Reardon, David A. , Wen, Patrick Y. , Bent, Martin J. van den , Chang, Susan M. , Weller, Michael , van den Bent, Martin J , Wick, Wolfgang , Borghei-Razavi, Hamid , Soffietti, Riccardo , Aghi, Manish Kumar , Galanis, Evanthia , Wen, Patrick Yung

Neuro-Oncology | June 19, 2020 | Volume: 22 | Issue: 11 | Pages: 1568-1579

10.1093/neuonc/noaa149 Get It

Abstract Glioblastoma is a devastating disease with poor prognosis. Few effective chemotherapeutics are currently available, and much effort has been expended to identify new drugs capable of slowing tumor progression. The phase 0 trial design was developed to facilitate early identification of promising agents for cancer that should undergo accelerated approval. This design features an early in-human study that enrolls a small number of patients who receive subtherapeutic doses of medication with the goals of describing pharmacokinetics through drug blood level measurements and determining intratumoral concentrations of the investigational compound as well as pharmacodynamics by studying the biochemical and physiological effects of drugs. In neuro-oncology, however, the presence of the blood–brain barrier and difficulty in obtaining brain tumor tissue warrant a separate set of considerations. In this paper, we critically reviewed the protocols used in all brain tumor related in-human phase 0 and phase 0–like (“window of opportunity”) studies between 1993 and 2018, as well as ongoing clinical trials, and identified major challenges in trial design as applied to central nervous system tumors that include surgical specimen collection and storage, brain tumor drug level analysis, and confirmation of drug action. We therefore propose that phase 0 trials in neuro-oncology should include (i) only patients in whom a resection of the tumor is planned, (ii) use of clinical doses of an investigational agent, (iii) tissue sampling from enhancing and non-enhancing portions of the tumor, and (iv) assessment of drug-specific target effects. Standardization of clinical protocols for phase 0/window of opportunity studies can help accelerate the development of effective treatments for glioblastoma.