Adjuvant phase III trial to compare intense dose-dense adjuvant treatment with EnPC to dose dense, tailored therapy with dtEC-dtD for patients with high-risk early breast cancer (GAIN-2).

Abstract

TPS1137 Background: Intense dose-dense (idd) chemotherapy (CT) significantly improves overall survival in breast cancer patients. Two preceding trials explored iddETC vs a dd combination of EC-TX (GAIN) and dtEC-dtD vs conventional dosed FEC-D (Panther). Nab-paclitaxel (nP) provides a better toxicity profile and higher efficacy compared to solvent based taxanes and might be preferred in an idd regimen. Methods: This is a multicenter, prospective, randomized, open-label phase III trial comparing iddEnPC or dtEC-dtD as adjuvant CT. Pts with uni- or bilateral primary high risk node-positive (N+) breast cancer (BC) and centrally confirmed ER/PR/HER2 and Ki-67 status can be included. Luminal A pts are only recruited with N+ ≥4. Randomization to iddEnPC or dtEC-dtD will be stratified by biological subtype defined by hormone receptor, HER2 and Ki-67. The iddEnPC arm will receive epirubicin (150mg/m2) q2w x3 followed by nP (260-330mg/m2, dose to be determined in run-in phase) q2w x3, followed by cyclophosphamide (2g/m2) q2w x3. The dtEC-dtD arm will receive EC (38-120/450-1200 mg/m2) q2w x4 followed after 1 wk rest by docetaxel (60-100mg/m2) q2w x4. GAIN-2 will compare toxicity and efficacy of an idd regimen (EnPC) vs a dd regimen with modification of single doses depending on individual hematological and non-hematological toxicities. Primary objective is invasive disease-free survival (IDFS). Secondary objectives are survival by other definitions, compliance, safety, side effects of taxanes and subgroup analyses (by 0-3, 4-9 or 10+ involved nodes and Ki-67). Efficacy analyses are planned 60 mths after end of accrual, safety interim analyses after 200 and 900 pts have completed CT. It was assumed that dtEC-dtD will achieve a 5-yr IDFS of 75% and ddEnPC will improve IDFS to 79% (HR 0.819) with a power of 80% (α=0.05, ß= 0.2).GAIN-2 is registered under NCT01690702 Results: 75pts were recruited since 1stOct 2012. Recruitment (in total 2886 pts) is planned for 36 mths in 80-100 sites in Germany. Run-in safety data to be presented. Conclusion: GAIN-2 will compare the efficacy of adjuvant iddEnPC and dtEC-dtD in pts with early N+ BC. Clinical trial information: NCT01690702.