Abstract OT1-06-01: A randomised trial comparing continuation or de-escalation of bone modifying agents (BMA) in patients treated for over 2 years for bone metastases from either breast or castration-resistant prostate cancer (REaCT-HOLD BMA)
Bibliographic record
Abstract
Abstract Background: Current guidelines recommend bone modifying agents (BMAs), such as bisphosphonates and denosumab, every 4 to 12 weeks to reduce the incidence of and delay the onset of symptomatic skeletal events (SSEs) in patients with bone metastases from breast cancer and castration-resistant prostate cancer (CRPC). Given the absence of level one evidence, the optimal frequency and duration of BMAs after 2 years of treatment is unknown. This is an important clinical question as the risk of SSEs decreases with time, while the risk of treatment-related toxicities increases. Methods: Patients with bone metastases from breast cancer or CRPC who have received ≥ two years of BMA treatment will be approached for this pragmatic, multicenter, open-label RCT. Using the Rethinking Clinical Trials (REaCT) methodology that incorporates the integrated oral consent model, eligible and consented patients will be randomized to either continue standard schedule BMA (every 4 or 12 weeks) or de-escalated BMA (every 24 weeks). This is a non-inferiority study. The co-primary endpoints are the physical functioning subscale of EORTC-QLQ-C30 and functional interference subscale of EORTC-QLQ-BM22. Secondary endpoints include number of patients with ≥ 1 SSE, time to development of SSE, SSE-free survival, skeletal morbidity rate, EORTC-QLQ-C30 and BM22 scores, BMA-related toxicity, and treatment adherence. To achieve 80% power for both co-primary endpoints and assuming a 10% non-compliance and 20% death rate, the planned sample size is 240 patients (120 per arm). Randomization (1:1 ratio) will be stratified by cancer type (breast vs prostate) and treatment schedule prior to randomization (Q4weeks vs. Q12weeks). A subgroup analysis comparing patients with 2-3 years vs. > 3 years of prior BMA treatment will be conducted. Results: The study has been open for enrollment since Oct 2020. As of July 5, 2021, the study has opened at 2 sites, 48 patients have been randomized and 8 are in screening. The study needs 60 patients randomized by September 2021 to continue to receive funding. There is a plan to open the study at two other academic centers in Ontario, Canada. Conclusion: This will be the first RCT providing level one evidence regarding the optimal frequency of BMA treatment that accounts for health-related quality of life after ≥ two years of prior BMA in this patient population. Citation Format: Terry L. Ng, Gregory R. Pond, Marta Sienkiewicz, Kednapa Thavorn, Mark Clemons. A randomised trial comparing continuation or de-escalation of bone modifying agents (BMA) in patients treated for over 2 years for bone metastases from either breast or castration-resistant prostate cancer (REaCT-HOLD BMA) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT1-06-01.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.005 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.004 | 0.004 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.003 | 0.005 |
| Insufficient payload (model declined to judge) | 0.020 | 0.003 |
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".