Afatinib alone or afatinib plus vinorelbine versus investigator's choice of treatment for HER2-positive breast cancer with progressive brain metastases after trastuzumab, lapatinib, or both (LUX-Breast 3): a randomised, open-label, multicentre, phase 2 trial.

BACKGROUND: Patients with advanced HER2-positive breast cancer frequently develop CNS metastases. The metastases that progress after brain radiotherapy and HER2-targeted systemic therapy are a difficult therapeutic challenge. We aimed to assess the efficacy and safety of afatinib, an irreversible blocker of the ErbB protein family, alone or combined with vinorelbine, compared with treatment of the investigator's choice in women with HER2-positive breast cancer with progressive brain metastases during or after treatment with trastuzumab, lapatinib, or both. METHODS: We did this randomised, open-label, multicentre, phase 2 trial in 40 hospitals in Canada, Finland, France, Germany, Italy, Spain, South Korea, and the USA. Women older than 18 years with histologically confirmed HER2-overexpressing breast cancer and CNS recurrence or progression as determined by Response Evaluation Criteria in Solid Tumors (RECIST version 1.1) during or after treatment with trastuzumab, lapatinib, or both, were eligible. We randomly assigned patients (1:1:1) centrally to afatinib 40 mg orally once per day, afatinib 40 mg per day plus intravenous vinorelbine 25 mg/m(2) once per week, or investigator's choice of treatment in cycles of 3 weeks until disease progression, patient withdrawal, or unacceptable toxicity. Treatment assignment was not masked for clinicians or patients, but the trial team was masked until database lock to reduce bias. The primary endpoint, assessed in the intention-to-treat population, was patient benefit at 12 weeks, defined by an absence of CNS or extra-CNS disease progression, no tumour-related worsening of neurological signs or symptoms, and no increase in corticosteroid dose. Safety was assessed in all patients who received at least one dose of a study drug. This completed trial is registered with ClinicalTrials.gov, number NCT01441596. FINDINGS: Between Dec 22, 2011, and Feb 12, 2013, we screened 132 patients, of whom 121 were eligible and randomly assigned to treatment: 40 to afatinib alone, 38 to afatinib plus vinorelbine, and 43 to investigator's choice. All patients discontinued study treatment before the data collection cutoff on Oct 16, 2014. Patient benefit was achieved in 12 (30·0%; 95% CI 16·6-46·5) patients given afatinib alone (difference vs investigator's choice: -11·9% [95% CI -32·9 to 9·7], p=0·37), 13 (34·2%; 19·6-51·4) given afatinib plus vinorelbine (difference vs investigator's choice: -7·6% [-28·9 to 14·2], p=0·63), and 18 (41·9%; 27·0-57·9) given investigator's choice. The most common treatment-related grade 3 or 4 adverse events were diarrhoea (seven [18%] of 40 patients in the afatinib only group vs nine [24%] of 37 patients in the afatinib plus vinorelbine group vs two [5%] of 42 patients in the investigator's choice group) and neutropenia (none vs 14 [38%] vs four [10%]). INTERPRETATION: Patient benefit with afatinib-containing treatments was not different from that in patients given investigator's choice of treatments; however, adverse events were frequent and afatinib-containing treatments seemed to be less well tolerated. No further development of afatinib for HER2-positive breast cancer is currently planned. FUNDING: Boehringer Ingelheim.

Phase Ib/II single-arm trial evaluating the combination of everolimus, lapatinib and capecitabine for the treatment of HER2-positive breast cancer with brain metastases (TRIO-US B-09).

BACKGROUND: Improving outcomes for patients with human epidermal growth factor 2-positive (HER2+) central nervous system (CNS) metastases remains an unmet clinical need. This trial evaluated a novel combination of everolimus, lapatinib and capecitabine for this disease. METHODS: Patients with trastuzumab-pretreated, HER2+ breast cancer brain metastasis without prior therapy with a mammalian target of rapamycin (mTOR) inhibitor were eligible. Patients received lapatinib and everolimus daily (continuously) and capecitabine twice daily (d1-14) in 21-d cycles. The primary endpoint was the 12-week CNS objective response rate (ORR). Secondary endpoints included safety, progression-free survival (PFS), overall survival (OS), best CNS ORR and extra-CNS ORR. RESULTS: A total of 19 participants were enrolled and treated with ⩾1 dose of the study drug. The median age was 58.5 years, the median number of therapies for metastatic breast cancer was 2.5 (0-11). Pretrial, 74% of participants had received prior lapatinib, capecitabine or both. A total of 63% had received previous CNS radiation or surgical resection and CNS radiation. The maximum tolerated doses were lapatinib at 1000 mg, everolimus at 10 mg, and capecitabine at 1000 mg/m2. Phase II proceeded with capecitabine at 750 mg/m2 due to better tolerability. The most common grade 3/4 adverse events were mucositis (16%), diarrhea, fatigue, and hypokalemia (11% each). Of 11 participants evaluable for 12-week CNS ORR, 3 (27%) had partial response and 7 (64%) had stable disease. The best CNS ORR in eligible participants was 28% (5/18). The median PFS and OS were 6.2 and 24.2 months, respectively. CONCLUSIONS: This novel triplet combination of lapatinib, everolimus, and capecitabine is well tolerated and yielded a 27% response rate in the CNS at 12 weeks in heavily pretreated participants. Larger studies are warranted to further evaluate this regimen. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01783756. Registered 05 February 2013, https://clinicaltrials.gov/ct2/show/NCT01783756.