Skin toxicity and efficacy of sunitinib and sorafenib in metastatic renal cell carcinoma: a national registry-based study

BACKGROUND

A retrospective, registry-based analysis to assess the outcomes of metastatic renal cell cancer (mRCC) patients treated with sunitinib and sorafenib who developed dermatologic adverse events was performed.

PATIENTS AND METHODS

Data on mRCC patients treated with sunitinib or sorafenib were obtained from the Czech Clinical Registry of Renal Cell Cancer Patients. Outcomes of patients who developed hand-foot syndrome (HFS) of any grade and/or grade 3/4 rash during the treatment were compared with patients without HFS and no, mild, or moderate rash.

RESULTS

The cohort included 705 patients treated with sunitinib and 365 patients treated with sorafenib. For sunitinib, the median overall survival (OS) was 43.0 months versus 31.0 months (P = 0.027) and median progression-free survival (PFS) 20.8 months versus 11.1 months (P = 0.007) for patients with versus without dermatologic toxicity, respectively. For sorafenib, the median OS and PFS were 27.9 and 24.6 months (P = 0.244), and 12.2 and 8.8 months (P = 0.050), respectively. In multivariable Cox regression, the skin toxicity was significantly associated with longer OS in the sunitinib cohort.

CONCLUSION

The presence of skin toxicity is associated with improved OS and PFS in patients with mRCC treated with sunitinib.

[BRAF mutation: a novel approach in targeted melanoma therapy]

The incidence of malignant melanoma is increasing worldwide, despite our best efforts in prevention and early detection. The locally advanced disease may be treated surgically with good results, however, metastatic melanoma is considered to be one of the most therapeutically challenging malignancies. The increasing knowledge of molecular changes in melanoma may change this picture. Malignant melanoma is not a singular, homogeneous disease but rather a mixture of subtypes characterized by specific mutations. Tumors with C-KIT mutation respond to therapy with C-KIT kinase inhibitor imatinib and the ones characterized by BRAF mutations respond to BRAF kinase inhibitor vemurafenib. Vemurafenib was approved by US FDA in 2011 and EMA in 2012 for therapy of patients with advanced melanoma, harboring mutation in BRAFV600E gene. Ipilimumab, an antibody to cytotoxic T-lymphocyte antigen 4 (CTLA-4), was registered in 2011 by both US FDA and European Medicines Agency for treatment of metastatic melanoma. This therapy promotes the anti-tumor T-cell activity by blocking a CTLA-4 antigen, a key negative regulator of immune response.

Hand–foot syndrome (HFS) as a potential biomarker of efficacy in patients (pts) with metastatic renal cell carcinoma (mRCC) treated with sunitinib (SU)

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Background: HFS and related skin toxicities are common side effects of tyrosine kinase inhibitors such as SU, a multitargeted inhibitor of VEGF and PDGF receptors plus other receptor tyrosine kinases. In a randomized phase III trial of treatment-naïve mRCC pts, SU showed superior progression-free survival (PFS) and objective response rate (ORR) over interferon-alfa, with a median PFS of 11 mo and median overall survival (OS) of 26.4 mo, establishing SU as a reference standard of care (Motzer et al, 2009). In this retrospective analysis, correlations between SU-associated HFS and efficacy endpoints were investigated in mRCC pts from 5 clinical trials in the first- and second-line treatment settings.

Methods: Analyses included pooled data from 770 pts who received single-agent SU as 50 mg/d on a 4-week-on/2-week-off schedule (n=544; 71%) or 37.5 mg continuous once-daily dosing (n=226; 29%). Median PFS and OS were estimated by Kaplan–Meier methods and compared between pts with vs without HFS using a log-rank test. ORR was compared by Pearson's chi-square test. Tumor response was assessed by investigators and adverse events were recorded regularly. Multivariate and time-dependent covariate analyses were performed.

Results: Of 770 pts, 179 (23%) developed any-grade HFS, compared with 591 (77%) who did not. Most instances of HFS (63%) initially occurred during the first 3 treatment cycles. Pts who developed HFS had significantly better ORR (55.6% vs. 32.7%), PFS (14.3 vs. 8.3 mo), and OS (38.3 vs. 18.9 mo) than pts who did not develop HFS (p<0.0001). In a multivariate analysis, SU-associated HFS remained a significant independent predictor of both PFS and OS (and of OS by time-dependent covariate analysis).

Conclusions: In mRCC pts, SU-associated HFS was significantly and independently associated with improved clinical outcomes. Overall, pts who did not develop HFS still had substantial benefit from SU. However, the presence of HFS identified a subset of pts that manifested highly favorable efficacy results with SU. These findings suggest that development of HFS may serve as a predictive biomarker of SU efficacy, although prospective validation is warranted.

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