Cabozantinib Versus Standard-of-Care Comparators in the Treatment of Advanced/Metastatic Renal Cell Carcinoma in Treatment-naïve Patients: a Systematic Review and Network Meta-Analysis

A Living, Interactive Systematic Review and Network Meta-analysis of First-line Treatment of Metastatic Renal Cell Carcinoma

CONTEXT

Identifying the most effective first-line treatment for metastatic renal cell carcinoma (mRCC) is challenging as rapidly evolving data quickly outdate the existing body of evidence, and current approaches to presenting the evidence in user-friendly formats are fraught with limitations.

OBJECTIVE

To maintain living evidence for contemporary first-line treatment for previously untreated mRCC.

EVIDENCE ACQUISITION

We have created a living, interactive systematic review (LISR) and network meta-analysis for first-line treatment of mRCC using data from randomized controlled trials comparing contemporary treatment options with single-agent tyrosine kinase inhibitors. We applied an advanced programming and artificial intelligence-assisted framework for evidence synthesis to create a living search strategy, facilitate screening and data extraction using a graphical user interface, automate the frequentist network meta-analysis, and display results in an interactive manner.

EVIDENCE SYNTHESIS

As of October 22, 2020, the LISR includes data from 14 clinical trials. Baseline characteristics are summarized in an interactive table. The cabozantinib + nivolumab combination (CaboNivo) is ranked the highest for the overall response rate, progression-free survival, and overall survival, whereas ipilimumab + nivolumab (NivoIpi) is ranked the highest for achieving a complete response (CR). NivoIpi, and atezolizumab + bevacizumab (AteBev) were ranked highest (lowest toxicity) and CaboNivo ranked lowest for treatment-related adverse events (AEs). Network meta-analysis results are summarized as interactive tables and plots, GRADE summary-of-findings tables, and evidence maps.

CONCLUSIONS

This innovative living and interactive review provides the best current evidence on the comparative effectiveness of multiple treatment options for patients with untreated mRCC. Trial-level comparisons suggest that CaboNivo is likely to cause more AEs but is ranked best for all efficacy outcomes, except NivoIpi offers the best chance of CR. Pembrolizumab + axitinib and NivoIpi are acceptable alternatives, except NivoIpi may not be preferred for patients with favorable risk. Although network meta-analysis provides rankings with statistical adjustments, there are inherent biases in cross-trial comparisons with sparse direct evidence that does not replace randomized comparisons.

PATIENT SUMMARY

It is challenging to decide the best option among the several treatment combinations of immunotherapy and targeted treatments for newly diagnosed metastatic kidney cancer. We have created interactive evidence summaries of multiple treatment options that present the benefits and harms and evidence certainty for patient-important outcomes. This evidence is updated as soon as new studies are published.

Nivolumab plus Cabozantinib versus Sunitinib for Advanced Renal-Cell Carcinoma

BACKGROUND

The efficacy and safety of nivolumab plus cabozantinib as compared with those of sunitinib in the treatment of previously untreated advanced renal-cell carcinoma are not known.

METHODS

In this phase 3, randomized, open-label trial, we randomly assigned adults with previously untreated clear-cell, advanced renal-cell carcinoma to receive either nivolumab (240 mg every 2 weeks) plus cabozantinib (40 mg once daily) or sunitinib (50 mg once daily for 4 weeks of each 6-week cycle). The primary end point was progression-free survival, as determined by blinded independent central review. Secondary end points included overall survival, objective response as determined by independent review, and safety. Health-related quality of life was an exploratory end point.

RESULTS

Overall, 651 patients were assigned to receive nivolumab plus cabozantinib (323 patients) or sunitinib (328 patients). At a median follow-up of 18.1 months for overall survival, the median progression-free survival was 16.6 months (95% confidence interval [CI], 12.5 to 24.9) with nivolumab plus cabozantinib and 8.3 months (95% CI, 7.0 to 9.7) with sunitinib (hazard ratio for disease progression or death, 0.51; 95% CI, 0.41 to 0.64; P<0.001). The probability of overall survival at 12 months was 85.7% (95% CI, 81.3 to 89.1) with nivolumab plus cabozantinib and 75.6% (95% CI, 70.5 to 80.0) with sunitinib (hazard ratio for death, 0.60; 98.89% CI, 0.40 to 0.89; P = 0.001). An objective response occurred in 55.7% of the patients receiving nivolumab plus cabozantinib and in 27.1% of those receiving sunitinib (P<0.001). Efficacy benefits with nivolumab plus cabozantinib were consistent across subgroups. Adverse events of any cause of grade 3 or higher occurred in 75.3% of the 320 patients receiving nivolumab plus cabozantinib and in 70.6% of the 320 patients receiving sunitinib. Overall, 19.7% of the patients in the combination group discontinued at least one of the trial drugs owing to adverse events, and 5.6% discontinued both. Patients reported better health-related quality of life with nivolumab plus cabozantinib than with sunitinib.

CONCLUSIONS

Nivolumab plus cabozantinib had significant benefits over sunitinib with respect to progression-free survival, overall survival, and likelihood of response in patients with previously untreated advanced renal-cell carcinoma. (Funded by Bristol Myers Squibb and others; CheckMate 9ER ClinicalTrials.gov number, NCT03141177.).

Comparative Efficacy of Cabozantinib and Regorafenib for Advanced Hepatocellular Carcinoma

Background

No trials have compared cabozantinib and regorafenib for the second-line treatment of advanced hepatocellular carcinoma (HCC).

Objectives

Conduct a matching-adjusted indirect comparison (MAIC) of the efficacy and safety of second-line cabozantinib and regorafenib in patients with advanced HCC and disease progression after prior sorafenib.

Methods

The CELESTIAL and RESORCE trials were used for indirect comparison of second-line cabozantinib and regorafenib in advanced HCC. Population-level data were available for RESORCE, individual patient data (IPD) for CELESTIAL. To align with RESORCE, the CELESTIAL population was limited to patients who received first-line sorafenib only. To minimize potential effect-modifying population differences, the CELESTIAL IPD were weighted to balance the distribution of clinically relevant baseline characteristics with those of RESORCE. Overall survival (OS) and progression-free survival (PFS) were evaluated for the matching-adjusted second-line CELESTIAL population and compared with those for RESORCE using weighted Kaplan-Meier curves and parametric modeling. Rates of grade 3/4 treatment-emergent adverse events (TEAEs) affecting > 5% of patients in any study arm were compared.

Results

In the matching-adjusted second-line populations (CELESTIAL, effective sample size = 266; RESORCE, n = 573), median (95% confidence interval) OS was similar for cabozantinib and regorafenib (11.4 [8.9–17.0] versus 10.6 [9.1–12.1] months; p = 0.3474, log-rank test). Median PFS was longer for cabozantinib than regorafenib (5.6 [4.9–7.3] versus 3.1 [2.8–4.2] months; p = 0.0005, log-rank test). There was a trend for lower rates of some grade 3/4 TEAEs with regorafenib than with cabozantinib, which may reflect the exclusion of sorafenib-intolerant patients from RESORCE but not from CELESTIAL, a difference that the MAIC methods could not remove. Only diarrhea rates were statistically significantly lower for regorafenib (p  ≤ 0.001).

Conclusions

Cabozantinib may achieve similar OS and prolonged PFS compared with regorafenib in patients with progressive advanced HCC after prior sorafenib.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-020-01378-y) contains supplementary material, which is available to authorized users.

Cabozantinib and regorafenib are treatments approved for some patients with advanced hepatocellular carcinoma (HCC), a type of liver cancer, after disease progression despite prior sorafenib treatment. Cabozantinib, regorafenib and sorafenib are tyrosine kinase inhibitors (TKIs), meaning that they slow cancer progression by targeting specific ways that tumors grow. Cabozantinib and regorafenib offer benefits to patients compared with placebo (i.e., no treatment) for those who have progressed despite sorafenib treatment. No clinical studies have compared cabozantinib and regorafenib directly. This study compared the efficacy and safety of cabozantinib and regorafenib using data from trials of each drug versus placebo: CELESTIAL for cabozantinib and RESORCE for regorafenib. These two trials were similar—both involved patients with progressive advanced HCC who had received previous cancer treatment. There were some important differences, but these were minimized using statistical methods (matching and adjustments/“weighting”) allowing outcomes to be meaningfully compared. One difference that could not be removed by the statistical methods was that patients who were intolerant to prior sorafenib were excluded from RESORCE but were eligible for the CELESTIAL trial. In the otherwise matched populations, treatment with cabozantinib was associated with similar overall survival and significantly longer progression-free survival than regorafenib. Rates of diarrhea were significantly lower for regorafenib than cabozantinib, suggesting that regorafenib may be better tolerated, but this may reflect the exclusion of sorafenib-intolerant patients from RESORCE. These findings cannot replace a head-to-head study, but may help in guiding decision-making between cabozantinib and regorafenib in patients with progressive advanced HCC after soraftenib treatment.

Systemic therapy in metastatic renal cell carcinoma: Emerging challenges in therapeutic choice

The treatment landscape for metastatic renal cell carcinoma (mRCC) has undergone a substantial evolution in the past decade, with a dramatic increase in the number of available systemic therapies. Although this offers promise for improved patient outcomes, this rapid pace in development has led to new challenges in therapeutic choice. For instance, the absence of direct comparative evidence across all therapeutic options has led to a critical gap in evidence to clearly define preferred systemic therapy choice. Additionally, the rising cost of systemic therapies being evaluated for mRCC necessitates demonstration of cost-effectiveness prior to widespread adoption. This review provides an overview of the current treatment landscape in mRCC to highlight the emerging challenges faced by clinicians and health policy-makers. In addition, this review summarizes the currently available evidence that aims to address the above challenges.

Anti-angiogenesis and Immunotherapy: Novel Paradigms to Envision Tailored Approaches in Renal Cell-Carcinoma

Although decision making strategy based on clinico-histopathological criteria is well established, renal cell carcinoma (RCC) represents a spectrum of biological ecosystems characterized by distinct genetic and molecular alterations, diverse clinical courses and potential specific therapeutic vulnerabilities. Given the plethora of drugs available, the subtype-tailored treatment to RCC subtype holds the potential to improve patient outcome, shrinking treatment-related morbidity and cost. The emerging knowledge of the molecular taxonomy of RCC is evolving, whilst the antiangiogenic and immunotherapy landscape maintains and reinforces their potential. Although several prognostic factors of survival in patients with RCC have been described, no reliable predictive biomarkers of treatment individual sensitivity or resistance have been identified. In this review, we summarize the available evidence able to prompt more precise and individualized patient selection in well-designed clinical trials, covering the unmet need of medical choices in the era of next-generation anti-angiogenesis and immunotherapy.

Spotlight on cabozantinib for previously untreated advanced renal cell carcinoma: evidence to date

Background

In the past few years, new drugs made their appearance in the first-line setting of treatment for metastatic renal cell carcinoma (mRCC), and cabozantinib is one among them. The present systematic review aims to point out any evidence published to date about first-line treatment with cabozantinib for mRCC patients, describing their outcome in all end points explored by the literature.

Methods

PRISMA guidelines were followed. A systematic assessment of literature and peer- reviewed presentations was performed by searching PubMed and major oncology meeting resources, from the database inception until June 25, 2018. The following keywords were used: "cabozantinib or cabozantinib-s-malate or XL184" and "renal cell carcinoma or kidney cancer or clear cell renal carcinoma or renal cancer" and "first-line or untreated or treatment-naïve or primary treatment". All types of original clinical studies were included, evaluating either cabozantinib monotherapy or any systemic drug combination containing cabozantinib for previously untreated patients with mRCC.

Results

From potential 75 titles and abstracts, seven publications were selected. One was the main report of a randomized clinical trial (the CABOSUN study); four papers reported updated results, secondary or subgroup analyses from the same study population; and further two reports consisted of network meta-analyses. From the additional search for ongoing clinical trials, six studies currently in progress were reported.

Conclusion

According to the reported evidence, cabozantinib may be a viable first-line option in mRCC patients with intermediate or poor risk according to International Metastatic Renal Cell Carcinoma Database Consortium model. It offers an undoubtful advantage in terms of progression-free survival, despite quite high rates of G3-4 toxicity, modest objective response rate, and no survival advantage. Nevertheless, given the availability of an immunotherapy combination that significantly improved overall survival for the same population in a Phase III trial and the indisputable efficacy of cabozantinib as second-line treatment, this drug may be devoted as a rescue option in patients progressive to primary therapy.

Cabozantinib as first-line treatment in advanced renal cell carcinoma: a profile of its use

Oral cabozantinib tablets (Cabometyx^®) are an important option for the treatment of advanced renal cell carcinoma (RCC). Cabozantinib is an anti-angiogenic agent and potently inhibits multiple tyrosine kinases, including those implicated in the development of RCC. The previously approved indication of cabozantinib tablets (i.e. treatment of advanced RCC following prior VEGF-targeted therapy) has been extended to include the first-line treatment of advanced RCC in treatment-naïve adults with intermediate or poor risk (EU) and all patients with advanced RCC (USA). These label extensions are based on the results of a randomized, open-label phase 2 trial, in which adults with metastatic RCC of poor or intermediate risk received targeted first-line treatment with cabozantinib or standard-of-care sunitinib. Relative to sunitinib, cabozantinib significantly prolonged median progression-free survival (primary endpoint; investigator and independent assessments), and increased the objective response rate (investigator assessment). The tolerability profile of cabozantinib is comparable to those of other tyrosine kinase inhibitors, with adverse events being manageable with medical intervention, dosage reductions, treatment interruption and/or permanent discontinuation.