Is there still a role for sorafenib in metastatic renal cell carcinoma? A systematic review and meta-analysis of the effectiveness of sorafenib over other targeted agents

Molecular targeting of renal cell carcinoma by an oral combination

The 5-year survival rate of patients with metastatic renal cell carcinoma (mRCC) is <12% due to treatment failure. Therapeutic strategies that overcome resistance to modestly effective drugs for mRCC, such as sorafenib (SF), could improve outcome in mRCC patients. SF is terminally biotransformed by UDP-glucuronosyltransferase-1A9 (A9) mediated glucuronidation, which inactivates SF. In a clinical-cohort and the TCGA-dataset, A9 transcript and/or protein levels were highly elevated in RCC specimens and predicted metastasis and overall-survival. This suggested that elevated A9 levels even in primary tumors of patients who eventually develop mRCC could be a mechanism for SF failure. 4-methylumbelliferone (MU), a choleretic and antispasmodic drug, downregulated A9 and inhibited SF-glucuronidation in RCC cells. Low-dose SF and MU combinations inhibited growth, motility, invasion and downregulated an invasive signature in RCC cells, patient-derived tumor explants and/or endothelial-RCC cell co-cultures; however, both agents individually were ineffective. A9 overexpression made RCC cells resistant to the combination, while its downregulation sensitized them to SF treatment alone. The combination inhibited kidney tumor growth, angiogenesis and distant metastasis, with no detectable toxicity; A9-overexpressing tumors were resistant to treatment. With effective primary tumor control and abrogation of metastasis in preclinical models, the low-dose SF and MU combinations could be an effective treatment option for mRCC patients. Broadly, our study highlights how targeting specific mechanisms that cause the failure of “old” modestly effective FDA-approved drugs could improve treatment response with minimal alteration in toxicity profile.

Comparative efficacy and safety of sunitinib vs sorafenib in renal cell carcinoma: A systematic review and meta-analysis

To evaluate the safety and efficiency of sunitinib and sorafenib in the treatment of renal cell carcinoma (RCC).Databases were searched up till February 28, 2018. Two reviewers independently assessed trials for eligibility, quality, and extracted relevant data. Results are expressed as risk ratio (RR) or hazard ratio (HR) with 95% confidence intervals (CI). Six studies including 3112 patients were accessed. Sorafenib group exhibited higher median progression-free survival (mPFS) compared to sunitinib group (MD, -1.30; 95% CI, -2.56 to -0.03), especially in the first-line treatment (MD, -1.33; 95% CI, -2.61 to -0.04). However, sunitinib significantly reduced the risk of progression-free survival (PFS) compared to sorafenib (HR, 0.71; 95% CI, 0.6-0.82). Sunitinib also significantly reduced risk of overall survival (OS) compared to sorafenib (HR, 0.79; 95% CI, 0.65-0.92), while median OS was similar in both groups (MD, -0.48; 95% CI, -3.40-2.43). With regards to safety, the risk of rash (RR, 0.31, 95% CI, 0.12-0.79) was greater in sunitinib than sorafenib group, while the risk of decreased appetite (RR 2.10, 95% CI: 1.33-3.30) and dehydration (RR 2.73, 95% CI: 1.14-6.56) was smaller in contrast.Based on risk of PFS and OS, sunitinib was a better treatment option for RCC treatment while patients faced with severe skin reaction. And for those Asian patients classified under MSKCC moderate risk, whether in first or second-line treatment, had difficulty in feeding, sorafenib is a better choice for prolong mPFS.

Sorafenib Versus Observation Following Radical Metastasectomy for Clear-cell Renal Cell Carcinoma: Results from the Phase 2 Randomized Open-label RESORT Study

BACKGROUND

In selected metastatic renal cell carcinoma (mRCC) patients, radical metastasectomy followed by observation is a potential strategy. It is still to be defined whether systemic therapy should be administered following metastasectomy.

OBJECTIVE

To assess the potential benefit of postoperative treatment with sorafenib compared with observation alone after radical metastasectomy in mRCC patients.

DESIGN, SETTING, AND PARTICIPANTS

The RESORT trial was a multicenter, randomized, open-label, phase 2 study conducted between November 2012 and November 2017 in Italy. Patients with clear-cell mRCC pretreated with nephrectomy and undergoing radical metastasectomy (three or fewer lesions) were eligible for the study. Patients were randomized (1:1) within 12 wk from metastasectomy to sorafenib (standard dose 400 mg twice daily) or observation for a maximum of 52 wk. Stratification factors were interval from nephrectomy, site, and number of lesions. Overall, 76 patients were screened and 69 were randomized: 33 were assigned to sorafenib and 36 to observation. The primary endpoint was recurrence-free survival (RFS). Secondary endpoints were overall survival and the safety profile.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

RFS curves were estimated with the Kaplan-Meier method, and the log-rank test was used to statistically compare the curves.

RESULTS AND LIMITATIONS

At a median follow-up of 38 mo, median RFS was 37 mo (95% confidence interval [CI] 20-not available [NA]) in the observation arm versus 21 mo (95% CI 11-NA) in the sorafenib arm (log-rank test p = 0.404), with 12-, 24-, and 36-mo RFS probability of 74% versus 63%, 59% versus 49%, and 50% versus 41%, respectively, in the observation versus the sorafenib arm. Any-grade adverse event (AE) rates were 84% in the sorafenib arm and 31% in the observation arm; grade ≥3 AE rates were 22% and 3% in the sorafenib and the observation arm, respectively, with a rate of treatment discontinuation for AEs of 19% in the sorafenib arm.

CONCLUSIONS

This prospective study showed that systemic treatment with sorafenib did not increase RFS as compared with observation in mRCC patients following radical metastasectomy.

PATIENT SUMMARY

This article reports the clinical outcome of patients with metastatic renal cell carcinoma treated with sorafenib or managed with an observation-alone strategy after the radical surgery of metastases. We found that sorafenib did not improve the patient outcome in terms of relapse-free survival in this selected population.

A meta-analysis of efficacy and safety of sorafenib versus other targeted agents for metastatic renal cell carcinoma

BACKGROUND

Molecular targeted therapies were found to be efficacious and safer in the treatment of metastatic renal cell carcinoma (mRCC). Sorafenib is the first target agent (TA) to report a benefit in this disease and has largely established a prominent role in progression-free survival (PFS). However, there have been conflicting results across the trials that evaluated the efficacy of sorafenib.

OBJECTIVE

The aim of the study was to perform a meta-analysis to compare the efficacy and safety of sorafenib in first-line treatments of mRCC.

METHODS

We searched online electronic databases: PubMed, Embase, and the Cochrane Library updated on September 2017. Trials on the efficacy of sorafenib in first-line treatments of advanced RCC were included, of which the primary outcomes were objective response rate (ORR), PFS, overall survival (OS), and grade 3/4 adverse events (AEs).

RESULTS

A total of 5 trials were included in this analysis. The group of AEs showed significantly improved PFS (odds ratio [OR] = 0.78, 95% confidence interval [CI] = 0.70-0.86, P < .001), as well with the ORR (OR = 1.89, 95%CI = 1.38-2.59, P < .0001) compared with sorafenib. However, there was no significant difference in OS (OR = 0.97, 95%CI = 0.78-1.22, P = .82).

CONCLUSION

Sorafenib did not achieve efficacy and safety benefit in patients with mRCC compared with those treated with TAs. The role of sorafenib in first-line treatments of mRCC may change in favor of newer drugs. More research is needed to confirm whether these new TAs could replace sorafenib as the gold standard in the future.

The Effectiveness of Sorafenib over Other Targeted Agents in the Second-Line Treatment of Metastatic Renal Cell Carcinoma: a Meta-Analysis

The aim of the study was to perform a meta-analysis to compare the therapeutic effects and adverse events (AEs) of sorafenib in second-line treatments of metastatic renal cell carcinoma (mRCC). We searched online electronic databases: Pubmed, Embase, Cochrane library updated on November 2017.Trials of the effectiveness of sorafenib in second-line treatments of advanced RCC were included, of which the main outcomes were objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and grade 3/4 AE. Other TAs significantly reduced the risk of PFS compared to sorafenib with respect to second-line treatment (HR = 0.74; 95% CI, 0.65-0.83; p < 0.00001). No significant differences were, however, found in patients in terms of the ORR (HR = 1.82; 95% CI, 0.98-3.35; p = 0.06). Frequencies of the most common toxicities were overall similar and adverse events differed only in sensitivity analysis in rash with exclusion of other TAs (HR = 0.16; 95% CI, 0.05-0.52; p = 0.002). Overall survival was not debated between groups. In patients with mRCC, second-line sorafenib is associated with similar ORR as other target agents. While, sorafenib did not demonstrate a PFS advantage compared with other target agents, suggests sorafenib may not benefit patients with mRCC. Tolerability due to toxicities is similar compared sorafenib with other target agents. Further characterization of the RCC oncogenic pathway, and the ongoing clinical trials should help optimize the treatment option for second-line therapy of advanced renal cell carcinoma.

A Vascular Endothelial Growth Factor-Dependent Sprouting Angiogenesis Assay Based on an In Vitro Human Blood Vessel Model for the Study of Anti-Angiogenic Drugs

Angiogenesis is the formation of new capillaries from pre-existing blood vessels and participates in proper vasculature development. In pathological conditions such as cancer, abnormal angiogenesis takes place. Angiogenesis is primarily carried out by endothelial cells, the innermost layer of blood vessels. The vascular endothelial growth factor-A (VEGF-A) and its receptor-2 (VEGFR-2) trigger most of the mechanisms activating and regulating angiogenesis, and have been the targets for the development of drugs. However, most experimental assays assessing angiogenesis rely on animal models. We report an in vitro model using a microvessel-on-a-chip. It mimics an effective endothelial sprouting angiogenesis event triggered from an initial microvessel using a single angiogenic factor, VEGF-A. The angiogenic sprouting in this model is depends on the Notch signaling, as observed in vivo. This model enables the study of anti-angiogenic drugs which target a specific factor/receptor pathway, as demonstrated by the use of the clinically approved sorafenib and sunitinib for targeting the VEGF-A/VEGFR-2 pathway. Furthermore, this model allows testing simultaneously angiogenesis and permeability. It demonstrates that sorafenib impairs the endothelial barrier function, while sunitinib does not. Such in vitro human model provides a significant complimentary approach to animal models for the development of effective therapies.

Effects and Side Effects of Using Sorafenib and Sunitinib in the Treatment of Metastatic Renal Cell Carcinoma

In recent years, targeted therapies have proven beneficial in terms of progression-free survival (PFS) and overall survival (OS) in the treatment of metastatic renal cell carcinoma (mRCC). The tyrosine kinase inhibitors (TKIs) sorafenib and sunitinib are included in international clinical guidelines as first-line and second-line therapy in mRCC. Hypertension is an adverse effect of these drugs and the degree of hypertension associates with the anti-tumour effect. Studies have compared newer targeted drugs to sorafenib and sunitinib in terms of PFS, OS, quality of life and safety profiles. Phase III studies presented promising response rates and acceptable safety profiles of axitinib and tivozanib compared to sorafenib, and a phase II study reported greater efficacy using a combination of bevacizumab and IFN-α compared to sunitinib. Treatment with nintedanib exhibited a notably low prevalence of hypertension compared to sunitinib. The use of sorafenib and sunitinib are challenged by new drugs, but do not appear likely to be substituted in the near future. To clarify whether newer targeted drugs should replace sorafenib and sunitinib, more research is needed. This manuscript reviews the current utility and adverse effects of sorafenib and sunitinib and newer targeted therapies in the treatment of mRCC.

Primary Tumor Characteristics Are Important Prognostic Factors for Sorafenib-Treated Patients with Metastatic Renal Cell Carcinoma: A Retrospective Multicenter Study

We aimed to identify prognostic factors associated with progression-free survival (PFS) and overall survival (OS) in metastatic renal cell carcinoma (mRCC) patients treated with sorafenib. We investigated 177 patients, including 116 who received sorafenib as first-line therapy, using the Cox regression model. During a median follow-up period of 19.2 months, the PFS and OS were 6.4 and 32.6 months among all patients and 7.4 months and undetermined for first-line sorafenib-treated patients, respectively. Clinical T3-4 stage (hazard ratio [HR] 2.56) and a primary tumor size >7 cm (HR 0.34) were significant prognostic factors for PFS among all patients, as were tumor size >7 cm (HR 0.12), collecting system invasion (HR 5.67), and tumor necrosis (HR 4.11) for OS (p < 0.05). In first-line sorafenib-treated patients, ≥4 metastatic lesions (HR 28.57), clinical T3-4 stage (HR 4.34), collecting system invasion (univariate analysis HR 2.11; multivariate analysis HR 0.07), lymphovascular invasion (HR 13.35), and tumor necrosis (HR 6.69) were significant prognosticators of PFS, as were bone metastasis (HR 5.49) and clinical T3-4 stages (HR 4.1) for OS (p < 0.05). Our study thus identified a number of primary tumor-related characteristics as important prognostic factors in sorafenib-treated mRCC patients.