Phase IB study of tovorafenib for children with relapsed/recurrent low-grade gliomas and other MAPK pathway activated tumors.
Bibliographic record
Abstract
10001 Background: LGGs present a therapeutic challenge often occurring in areas of brain and spine not amenable to resection and carrying high morbidity with currently available therapies. The majority harbor alterations in the MAPK pathway. Our study (NCT03429803) aimed to establish the recommended phase 2 dose (RP2D) and assess the safety, tolerability and preliminary efficacy of type II RAF-inhibitor tovorafenib in such tumors. Methods: Eligible patients were > 1 year and < 25 years old with radiographically recurrent/progressive MAPK pathway-altered tumors. We applied a novel 2S-Sub-TITE design to determine a RP2D with posterior probability of toxicity closest to the 20% target for patients with BSA ≤1.5 and > 1.5 m2 based on preliminary exposure-efficacy data. Toxicities were graded according to CTCAE version 5. Patients with complete response (CR), partial response (PR) or stable disease (SD) were designated responders. Results: We treated 35 eligible patients, including 20 KIAA1549:BRAF-, 9 BRAF V600E- and 1 FGFR1-altered tumors; 5 possessed novel RAF fusions. Histologically, there were 27 grade 1 gliomas, 3 anaplastic pleomorphic xanthoastrocytomas, 3 pilomyxoid astrocytomas, 1 high-grade glioma and 1 soft tissue sarcoma. There were 6 grade 3 DLTs (2 fatigue, 3 rash, 1 menorrhagia) in 30 evaluable patients: 3 in each BSA subgroup, all at 530 mg/m2/dose. Using AAP guidelines for minimum pubertal peak growth velocities (GV) in males (7 cm/year) and females (6 cm/year), decreased GV (median 0.09 cm/year; range 0.02-0.3) was an unexpected, related AE observed in all 13 of 13 pre-pubertal females < 14 or males < 16 years of age receiving >6 months of protocol 1B therapy. Three of 13 patients with decreased GV were treated at 420 mg/m2. Three of the remaining 10 patients with decreased GV originally treated at 530 mg/m2 were dose reduced for other toxicities and hence, 6 of 13 patients with decreased GV were treated at the RP2D. For patients with follow-up data available, GV appears to show recovery off drug. The 2S-Sub-TITE model recommended 530 mg/m2 for BSA ≤1.5m2 and 420 mg/m2 for BSA > 1.5m2. Dose modifications were required in 8/22 versus 1/13 patients treated at 530 and 420 mg/m2, respectively. Twenty-seven of 35 patients were evaluable for objective response performed by an independent single reader. Overall, 25 patients had SD, PR or CR with median duration of response of 11.3 months (range 0.03-35.4) at data cutoff. Conclusions: Oral weekly tovorafenib is well tolerated and shows preliminary efficacy. Decreased GV was observed in pre-pubertal patients on drug and warrants further investigation to understand the mechanism of action. Based on the number of dose modifications required for toxicity, the chosen RP2D for weekly oral dosing of tovorafenib was 420 mg/m2. Clinical trial information: NCT03429803 .
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 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".