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Rash is a common side effect of lapatinib treatment. Since human leukocyte antigen ( HLA) alleles have been implicated in multiple drug-induced cutaneous reactions, this study investigated the association of HLA alleles with lapatinib-induced rash. 1191 participants from a large lapatinib monotherapy trial underwent HLA genotyping, and allele carriage frequencies between rash cases and controls were compared. This analysis had adequate power to detect an association of common HLA alleles with rash, similar to those reported previously. No HLA alleles were significantly associated with lapatinib-induced rash, including the previously identified lapatinib hepatotoxicity biomarker HLA-DRB1*07:01 (p = 0.87). The present study is consistent with the view that lapatinib-induced rash is not the consequence of HLA-restricted, immune-mediated mechanisms. [ABSTRACT FROM AUTHOR]

In resource-constrained environments many patients with human epidermal growth factor receptor 2 (HER2)+ early breast cancer are currently not offered adjuvant anti-HER2 therapy. For patients who might be able to receive the tyrosine kinase inhibitor (TKI) lapatinib (e.g. after patent expiration), it is important to identify subgroups of patients for whom anti-HER2 TKI therapy could be beneficial. To do this, we used data from 2489 patients with centrally confirmed HER2+ disease enrolled in the adjuvant Tykerb Evaluation After Chemotherapy (TEACH) trial, investigating the effect of lapatinib in patients with HER2+ early breast cancer not treated with trastuzumab. We performed subgroup analyses and number-needed-to-treat (NNT) calculations using patient and tumour associated predictors. Hormone receptor negative (HR−) patients on lapatinib had a significantly prolonged disease-free survival (DFS) compared to HR− patients on placebo (hazard ratio 0.64, P = 0.003). For patients with HR– disease, starting treatment with lapatinib ≤1 year from diagnosis improved DFS by 12.1% [2.1–22.1] at 2 years and 15.7% [4.1–27.2] at 5 years. Depending on lymph node status and time since diagnosis the NNT for recurrence (at 5 years) was between 5.9 (node positive patients <1 year from diagnosis) and 15.9. These numbers are in range with numbers reported for up-front adjuvant trastuzumab for HR unselected patients (e.g. 15.6 for DFS at 4 years in HERA). In a subgroup analysis of the adjuvant TEACH trial, we show that anti-HER2 monotherapy with a TKI is beneficial as adjuvant therapy in a subgroup of patients. NNT in HER2+ HR– patients are in range with those reported from up-front adjuvant trastuzumab trials. [ABSTRACT FROM AUTHOR]

Summary Background To evaluate health related quality of life (HRQOL) in TEACH, a phase III randomized placebo controlled trial of 12 months of adjuvant lapatinib in HER2 positive (HER2+) early breast cancer which demonstrated marginal benefit in disease-free survival. Methods Women on TEACH completed the Short Form 36-item health survey (version2; SF-36v2) at the baseline, six and 12 months after therapy initiation and six monthly thereafter. Mean changes were compared between treatment groups for two summary measures (Physical and Mental Component Summary scores; PCS and MCS) and eight domain measures (physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional and mental health), and in patients discontinuing therapy. A five-point change was deemed a Minimally Clinically Important Difference (MCID). Response analysis compared the proportion of patients demonstrating a MCID in HRQOL, and a regression analysis identified predictors of worsening HRQOL. Findings 3074 (97%) subjects completed baseline SF-36v2. During the initial 12 months, summary SF-36v2 scores decreased in both arms but did not reach Minimally Clinically Important Difference (MCID) despite significant incidences of diarrhoea and rash in lapatinib treated patients. At six months, women receiving lapatinib had more significant reductions ( p < 0.01 versus placebo) in social functioning. Early treatment discontinuations were more frequent on lapatinib (32% versus 18%), and were associated with more substantial decrements of HRQOL in both arms. For those discontinuing primarily due to adverse events, decrements in HRQOL reached MCID in Mental Summary scores (MCS) only. Lower baseline HRQOL was a significant predictor of worsening HRQOL ( p < 0.05). Interpretation Despite frequent but usually mild toxicities, adjuvant lapatinib is not associated with clinically significant decreases in overall HRQOL. These placebo-controlled results may also help to inform physicians and patients using lapatinib in metastatic HER2 positive breast cancer. Funding GlaxoSmithKline. The AVON Foundation NY supported PEG, DF and BM and The Friends of the Mater Foundation supported FB. [ABSTRACT FROM AUTHOR]

Summary: Background: Worldwide, many patients with HER2-positive early stage breast cancer do not receive trastuzumab—the standard adjuvant treatment. We investigated the efficacy and safety of adjuvant lapatinib for patients with trastuzumab-naive HER2-positive early-stage breast cancer, started at any time after diagnosis. Methods: This study was a placebo-controlled, multicentre, randomised phase 3 trial. Women outpatients from 33 centres with HER2-positive early-breast cancer who had previously received adjuvant chemotherapy but not trastuzumab were randomly assigned (1:1) to receive daily lapatinib (1500 mg) or daily placebo for 12 months. Randomisation was done with a computer-generated sequence, stratified by time since diagnosis, lymph node involvement at diagnosis, and tumour hormone-receptor status. Investigators, site staff, and patients were masked to treatment assignment. The primary endpoint was disease-free survival in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT00374322. Findings: Between August, 2006, and May, 2008, 3161 women were enrolled and 3147 were assigned to lapatinib (n=1571) or placebo (n=1576). After a median follow-up of 47·4 months (range 0·4–60·0) in the lapatinib group and 48·3 (0·7–61·3) in the placebo group, 210 (13%) disease-free survival events had occurred in the lapatinib group versus 264 (17%) in the placebo group (hazard ratio [HR] 0·83, 95% CI 0·70–1·00; p=0·053). Central review of HER2 status showed that only 2490 (79%) of the randomised women were HER2-positive. 157 (13%) of 1230 confirmed HER2-positive patients in the lapatinib group and in 208 (17%) of 1260 in the placebo group had a disease-free survival event (HR 0·82, 95% 0·67–1·00; p=0·04). Serious adverse events occurred in 99 (6%) of 1573 patients taking lapatinib and 77 (5%) of 1574 patients taking placebo, with higher incidences of grade 3–4 diarrhoea (97 [6%] vs nine [<1%]), rash (72 [5%] vs three [<1%]), and hepatobiliary disorders (36 [2%] vs one [<1%]). Interpretation: Our data show that there was no significant difference in disease-free survival between groups when analysed in the intention-to-treat population. However, exploratory analyses restricted to patients who had HER2-positive disease confirmed by central fluorescence in-situ hybridisation review suggested marginal benefit with lapatinib in terms of disease-free survival. Thus lapatinib might be an option for women with HER2-positive breast cancer who do not or cannot receive adjuvant trastuzumab. Funding: GlaxoSmithKline. [Copyright &y& Elsevier]