KEY TAKEAWAYS
- A phase 2 randomized clinical trial (ATTAIN) compared etirinotecan pegol to chemotherapy for metastatic breast cancer and stable, pretreatment BM.
- OS was the primary goal.
- Secondary outcomes included progression-free survival, objective response rate, duration of response, and clinical benefit rate.
- ATTAIN trial shows no significant difference between etirinotecan pegol and chemotherapy for BM patients with breast cancer. This study, one of the largest in this population, can guide future research.
Patients with breast cancer who have brain metastases (BM) have a high clinical demand for novel treatments yet a dismal prognosis, yet they have often been left out of studies in the past. Although the primary endpoint of the BEACON study was not reached, the prespecified patient subgroup with preexisting, pretreated, and nonprogressive BM showed a significant improvement in overall survival (OS) when treated with etirinotecan pegol versus chemotherapy of the physician’s choice for patients with advanced breast cancer.
This confirmatory trial evaluated the efficacy of etirinotecan pegol versus chemotherapy of the treating physician’s choosing in patients with BM. Patients with metastatic breast cancer with a history of stable pretreatment BM who suffered disease progression while undergoing chemotherapy in the metastatic setting were enrolled in the ATTAIN project, a phase 3, open-label, randomized clinical trial. Patients were enrolled from March 7, 2017, to November 6, 2019, at 47 sites in 10 countries. Participants were randomly assigned to receive chemotherapy or etirinotecan pegol (145 mg/m2) every 21 days (eribulin, ixabepilone, vinorelbine, gemcitabine, paclitaxel, docetaxel, or nab-paclitaxel).
OS was the primary metric of success. The rate of clinical benefit, the length of response, the rate of objective response, and the rate of progression-free survival were all secondary end objectives. There were a total of 178 female patients randomized to receive either etirinotecan pegol (92 [51.7%]; median [range] age, 53 [27-79] years) or chemotherapy (86 [48.3%]; median [range] age, 52 [24-77] years). There were 9 [5.1%] Asian patients, 8 [4.5%] Black or African American patients, and 123 [69.1] White patients. The median overall survival for those treated with etirinotecan pegol and those treated with chemotherapy was 7.8 months and 7.5 months, respectively (hazard ratio [HR], 0.90; 95% CI, 0.61-1.33; P =.60).
According to a blinded independent central review, the median progression-free survival for patients with non-central nervous system metastases treated with etirinotecan pegol compared to chemotherapy was 2.8 months (HR, 0.72; 95% CI, 0.45-1.16; P =.18) and 3.9 months (HR, 0.59; 95% CI, 0.33-1.05; P =.07). The risk profiles of the two groups were very similar. According to the ATTAIN randomized clinical trial results, there was no statistically significant difference in outcomes between etirinotecan pegol and chemotherapy in patients with BM. Nonetheless, as one of the most extensive published trials for breast cancer and BM patients, this study can potentially guide future investigations.
Source:https://pubmed.ncbi.nlm.nih.gov/35552364/
Clinical Trial: https://clinicaltrials.gov/ct2/show/NCT02915744
Tripathy D, Tolaney SM, Seidman AD, Anders CK, Ibrahim N, Rugo HS, Twelves C, Diéras V, Müller V, Du Y, Currie SL, Hoch U, Tagliaferri M, Hannah AL, Cortés J; ATTAIN Investigators. Treatment With Etirinotecan Pegol for Patients With Metastatic Breast Cancer and Brain Metastases: Final Results From the Phase 3 ATTAIN Randomized Clinical Trial. JAMA Oncol. 2022 Jul 1;8(7):1047-1052. doi: 10.1001/jamaoncol.2022.0514. PMID: 35552364; PMCID: PMC9100460.
