P14.02.B A MULTICENTER, RANDOMIZED, CONTROLLED TRIAL OF FOCUSED-ULTRASOUND-MEDIATED BLOOD-BRAIN BARRIER DISRUPTION PLUS SYSTEMIC PEMBROLIZUMAB FOR PATIENTS WITH NSCLC BRAIN METASTASES (LIMITLESS)
Bibliographic record
Abstract
Abstract BACKGROUND The efficacy of systemic therapies for brain metastases (BM) is hindered by the blood-brain barrier (BBB), whose disruption is associated with improved systemic drug delivery. Low-intensity focused ultrasound (LIFU), combined with IV microbubble oscillators, leads to non-invasive disruption of BBB. This can potentially enhance intracranial drug delivery of systemically administered immune checkpoint inhibitors like pembrolizumab. Given that non-small lung cancer (NSCLC) remains the most common etiology behind BM, this randomized controlled trial (RCT) aims to evaluate the safety and efficacy of LIFU-mediated BBB disruption combined with systemic pembrolizumab for NSCLC BM. MATERIAL AND METHODS LIMITLESS is an ongoing, prospective, multicenter, parallel-arm, open-label RCT that randomizes patients with NSCLC BM on pembrolizumab monotherapy prescribed as per standard-of-care to LIFU plus pembrolizumab (arm 1) or pembrolizumab alone (arm 2) in a 2:1 ratio. Included patients have age ≥18 years, normal organ function, KPS ≥70, EGFR- and ALK-negative primary tumor, and ≤3 BM with ≥1 BM meeting measurable disease criteria as per RANO-BM. Patients on both arms receive standard-of-care therapy, while those on arm 1 also undergo LIFU before each dose of pembrolizumab (200 mg IV every 3 weeks). Patients undergo pre-treatment brain MRI, followed by IV administration of microbubbles for enhanced sonication effects. MR-guided BBB disruption is then performed using a transcranial 220 kHz LIFU device with real-time acoustic feedback-based power control for maintaining effective microbubble activation. Pembrolizumab is infused immediately after the sonication, and a repeat MRI is done 24-48 hours later to assessment to treatment effects. The primary study outcome is the overall objective response rate (ORR) at 6 months as assessed using RANO-BM criteria. Using a Bayesian design for power analysis, a superior ORR of 60% is assumed for the LIFU arm versus 30% in the control arm for a total sample size of N = 96, 64 participants in LIFU and 32 in the control arm, for 80% power using a two-sided chi-square test with an alpha of 0.05. For the upper-bound estimate, ORR of 45% in the LIFU arm and 30% in the control arm, the study needs N = 369 participants: 246 in LIFU arm and 123 in control arm. The secondary outcomes are best objective response rate and median time-to-response per treatment arm. Exploratory outcomes are median progression-free survival (PFS), overall survival (OS), median intracranial PFS, median extracranial PFS, and quality of life. RESULTS Patient enrollment commenced in 2022 and is ongoing. CONCLUSION Findings from this trial will be critical to overcoming the historic challenges presented by the BBB to efficacious CNS drug delivery (ClinicalTrials.Gov Registration: NCT05317858).
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.002 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.013 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".