P07.13.B A RANDOMIZED STUDY OF LOW-INTENSITY FOCUSED ULTRASOUND FOR BLOOD-BRAIN BARRIER DISRUPTION FOR BRAIN METASTASIS FROM NON-SMALL CELL LUNG CANCER (LIMITLESS)
Bibliographic record
Abstract
Abstract BACKGROUND The blood-brain barrier (BBB) limits the efficacy of systemic therapies for brain metastases (BM), for which non-small cell lung cancer (NSCLC) is the most common etiology. BBB disruption (BBBD) has been demonstrated, in preclinical models, to improve systemic drug delivery for BM. Low-intensity focused ultrasound (LIFU) results in non-invasive BBBD synergistically with intravenously (IV) administered microbubble oscillators. This randomized controlled trial (RCT) aims to determine the safety and efficacy of LIFU-mediated BBBD for NSCLC BM with immunotherapy. 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 2:1 ratio. Included patients have age ≥18 years, normal organ function, Karnofsky Performance Status ≥70, EGFR- and ALK-negative primary tumor, and ≤3 BM with ≥1 BM meeting measurable disease criteria as per response assessment in neuro-oncology for BM (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). These patients undergo pre-treatment MRI brain, followed by IV administration of oscillating microbubbles for enhanced sonication. MR-guided BBBD is then performed using a 220 kHz LIFU device with real-time acoustic feedback for maintaining effective cavitation. Pembrolizumab is infused immediately thereafter, and a repeat MRI is done 24-48 hours later to confirm the closure of BBB each cycle. The primary study endpoint 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 subjects 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 subjects; 246 in the LIFU arm and 123 in the control arm. The secondary outcomes are the best objective response rate and median time-to-response per treatment arm. The 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. CONCLUSION Findings from this trial will be critical to liquid biopsy in brain metastases (Clinical trial information: 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 | 0.003 | 0.003 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.002 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.015 | 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".