Abstract | Importance: Objective: Design, Setting, and Participants: This phase 1 prospective dose-escalation trial ( Olaparib and Radiation Therapy for TNBC [RadioPARP] trial) using a time-to-event continual reassessment method was performed from September 2017 to November 2019, with follow-up until November 2021. Participants had an incomplete pathologic response after neoadjuvant chemotherapy or unresectable TNBC despite previous neoadjuvant chemotherapy, an Eastern Cooperative Oncology Group Performance Status score of 0 or 1, and adequate organ functions. Interventions:
Olaparib was administered orally in the form of tablets and given at increasing doses (50 mg, 100 mg, 150 mg, or 200 mg twice daily). Olaparib therapy was started 1 week before radiotherapy and was continued concomitantly with radiotherapy. After breast-conserving surgery, a total dose of 50.4 Gy was delivered to the whole breast, with a 63-Gy simultaneously integrated boost to the tumor bed for patients younger than 60 years. After radical mastectomy or for unresectable tumors despite neoadjuvant chemotherapy, a total dose of 50.0 Gy was delivered to the chest wall (after mastectomy) or to the whole breast (for unresectable tumors). Regional lymph node stations could be treated with a total dose of 50.0 Gy to 50.4 Gy in cases of node-positive disease. Main Outcomes and Measures: Main outcomes were the safety and tolerability of PARP inhibition with radiotherapy for early-stage, high-risk TNBC. Secondary outcomes included overall survival (OS) and event-free survival (EFS). Results: Among the 24 patients included in the trial (100% female; median age, 46 years [range, 25-74 years]), no dose-limiting toxic effects were observed, and olaparib was escalated to 200 mg twice daily without reaching the maximum tolerated dose. No late treatment-related grade 3 or greater toxic effect was observed, and the maximum observed treatment-related toxic effects at the 2-year follow-up were grade 2 breast pain, fibrosis, and deformity in 1 patient (4.2%). Three-year OS and EFS were 83% (95% CI, 70%-100%) and 65% (95% CI, 48%-88%), respectively. Homologous recombination status was not associated with OS or EFS. Conclusions and Relevance: The findings of this phase 1 dose-escalation trial suggest that PARP inhibition with olaparib concurrently with radiotherapy for early-stage, high-risk TNBC is well tolerated and should continue to be evaluated in further clinical trials. Trial Registration: ClinicalTrials.gov Identifier: NCT03109080.
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Authors | Pierre Loap, Delphine Loirat, Frederique Berger, Manuel Rodrigues, Louis Bazire, Jean-Yves Pierga, Anne Vincent-Salomon, Fatima Laki, Latifa Boudali, Laurence Raizonville, Veronique Mosseri, Anne Jochem, Alexandre Eeckhoutte, Mamadou Diallo, Marc-Henri Stern, Alain Fourquet, Youlia Kirova |
Journal | JAMA oncology
(JAMA Oncol)
Vol. 8
Issue 12
Pg. 1802-1808
(12 01 2022)
ISSN: 2374-2445 [Electronic] United States |
PMID | 36301572
(Publication Type: Clinical Trial, Phase I, Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- olaparib
- Poly(ADP-ribose) Polymerase Inhibitors
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Topics |
- Humans
- Female
- Middle Aged
- Male
- Triple Negative Breast Neoplasms
(drug therapy, radiotherapy)
- Poly(ADP-ribose) Polymerase Inhibitors
(adverse effects)
- Prospective Studies
- Antineoplastic Combined Chemotherapy Protocols
(therapeutic use)
- Mastectomy
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