Maintenance Lapatinib Fails to Improve PFS in HER1/2+ Bladder Cancer
Maintenance therapy with lapatinib did not significantly improve PFS or OS in HER1/HER2-positive metastatic urothelial bladder cancer.
Maintenance therapy with lapatinib did not significantly improve progression-free survival or overall survival compared with standard care among patients with HER1/HER2-positive metastatic urothelial bladder cancer, according to a study published in the Journal of Clinical Oncology.1
To evaluate whether maintenance lapatinib after frontline chemotherapy is beneficial in HER1/HER2-positive bladder cancer, researchers enrolled 446 patients with metastatic urothelial carcinoma and centrally screened them for HER1/HER2 overexpression.
A total of 232 patients who tested positive for HER1/HER2 and did not have disease progression following 4 to 8 cycles of chemotherapy were randomly assigned to receive lapatinib or placebo after completion of first-line chemotherapy for metastatic disease.
There was no significant difference in progression-free survival or overall survival between the 2 treatment arms. Median progression-free survival was 4.5 months (95% CI, 2.8-5.4) with lapatinib compared with 5.1 months (95% CI, 3.0-5.8) with placebo (hazard ratio [HR], 1.07; 95% CI, 0.81-1.43; P = .63).
The median overall survival for lapatinib and placebo was 12.6 months (95% CI, 9.0-16.2) and 12.0 months (95% CI, 10.5-14.9), respectively (HR, 0.96; 95% CI, 0.70-1.31; P = .80).
A significant proportion of patients who received placebo had continued response, suggesting that chemotherapy was conferring ongoing activity beyond the last dose administered.
Subgroup analyses demonstrated that patients who tested strongly positive for HER1/HER2 on immunohistochemistry, patients positive only for HER1, and patients positive only for HER2 did not gain any significant benefit with lapatinib with respect to progression-free or overall survival (P > .05).
There was no significant difference in the rate of grade 3 to 4 adverse events between the 2 groups (P = .82) and discontinuation due to adverse events was similar in both arms.
- Powles T, Huddart RA, Elliot T, et al. Phase III, Double-blind, randomized trial that compared maintenance lapatinib versus placebo after first-line chemotherapy in patients with human epidermal growth factor receptor 1/2–positive metastatic bladder cancer. J Clin Oncol. 2016 Oct 28. doi: 10.1200/JCO.2015.66.3468 [Epub ahead of print]