Optimizing further treatment choices in short- and long-term responders to first-line therapy for patients with advanced renal cell carcinoma

Time to progression after first-line tyrosine kinase inhibitor predicts survival in patients with metastatic renal cell carcinoma receiving second-line molecular-targeted therapy

OBJECTIVES

The effect of response to first-line tyrosine kinase inhibitor (TKI) therapy on second-line survival in patients with metastatic renal cell carcinoma who receive second-line molecular-targeted therapy (mTT) after first-line failure remains unclear.

MATERIALS AND METHODS

Sixty patients who developed disease progression after first-line TKI, without prior cytokine therapy, were enrolled. According to the median first-line time to progression (1L-TTP), patients were divided into 2 groups (i.e., short vs. long). Second-line progression-free survival (2L-PFS) and second-line overall survival (2L-OS) were defined as the time from second-line mTT initiation. Survival was calculated with the Kaplan-Meier method and compared using the log-rank test between patients with short and long 1L-PFS. Predictors for survivals were identified using Cox proportional hazards regression models.

RESULTS

The median 1L-TTP was 8.84 months. Thirty patients (50.0%) with short 1L-TTP (<8.84mo) had significantly shorter 2L-PFS and 2L-OS compared to patients with long 1L-TTP (2L-PFS: 4.96 vs. 10.2mo, P = 0.0002; 2L-OS: 9.6 vs. 28.0mo, P = 0.0036). Multivariable analyses for 2L-PFS and 2L-OS showed that 1L-TTP was an independent predictor both as a categorical classification (cutoff: 8.84mo) and as a continuous variable (both P<0.05). The median follow-up duration was 13.1 months (interquartile range: 6.56-24.7).

CONCLUSIONS

Patients who achieve a long-term response after first-line TKI therapy could have a favorable prognosis with second-line mTT.

Evaluation of second-line and subsequent targeted therapies in metastatic renal cell cancer (mRCC) patients treated with first-line cediranib

INTRODUCTION

Pivotal phase III trials have positioned angiogenesis inhibitors as first-line therapy for the management of most advanced or metastatic renal cell carcinomas (mRCC). Approaches to second-line therapy, however, remain more controversial with respect to drug selection and drug sequencing.

METHODS

In this study we evaluated mRCC patients who were initially treated on the first-line National Cancer Institute (NCI) trial with the highly potent vascular endothelial growth factor receptor tyrosine kinase inhibitor (TKI), cediranib, to determine the efficacy and tolerability of subsequent therapies.

RESULTS

Twenty-eight (65.1%) of the 43 patients enrolled on the first-line cediranib trial were known to receive second-line therapy, most commonly sunitinib (n = 21), with 4 (14%), 2 (7%) and 1 (3%) patients receiving temsirolimus, sorafenib, and interleukin, respectively. Of these, 14 (50%) went on to have 3 or more lines of therapy. The progression-free survival (PFS) proportion (PFS) at 1 year from starting second line was 30% (14.5%-47.9%). Longer duration of first-line cediranib treatment was modestly associated with longer duration of second-line treatment (Spearman rho 0.26). Patients who discontinued cediranib for toxicity were less likely to receive second-line sunitinib.

CONCLUSION

In this real world evaluation, sequential use of TKIs for the management of mRCC was common. PFS with sequential TKIs was similar to observed and published results for any second-line therapy. Prior toxicity affected treatment patterns and the frequent use of at least 3 lines of therapy underscores the need for prospective sequencing trials in this disease.

Using cumulative toxicity to identify the optimal second-line targeted therapy in patients with metastatic renal cell carcinoma: what's new?

The life expectancy in metastatic renal cell carcinoma patients treated with targeted therapies can be influenced by the time spent on treatment, and the current focus of clinical research in this field appears to be on extending the time on treatment while limiting toxicities. It has been proposed that a strategy based on the sequential administration of two tyrosine kinase inhibitors could result in unacceptable cumulative toxicity for many metastatic renal cell carcinoma patients, while switching to a mTOR inhibitor does not. However, a definite consensus on this issue has not been reached. As very little information from head-to-head studies is available, clinicians have to base their treatment decisions on existing evidence, with an obvious preference for high-quality studies. Some recent studies have provided new insights into the issue of cumulative toxicity of second-line targeted therapies in metastatic renal cell carcinoma patients. In this article, we discuss the evidence emerging from the randomized AXIS and RECORD-3 trials.