First-line therapy for adults with advanced renal cell carcinoma: a systematic review and network meta-analysis

BACKGROUND

Since the approval of tyrosine kinase inhibitors, angiogenesis inhibitors and immune checkpoint inhibitors, the treatment landscape for advanced renal cell carcinoma (RCC) has changed fundamentally. Today, combined therapies from different drug categories have a firm place in a complex first-line therapy. Due to the large number of drugs available, it is necessary to identify the most effective therapies, whilst considering their side effects and impact on quality of life (QoL).

OBJECTIVES

To evaluate and compare the benefits and harms of first-line therapies for adults with advanced RCC, and to produce a clinically relevant ranking of therapies. Secondary objectives were to maintain the currency of the evidence by conducting continuous update searches, using a living systematic review approach, and to incorporate data from clinical study reports (CSRs).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, conference proceedings and relevant trial registries up until 9 February 2022. We searched several data platforms to identify CSRs.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating at least one targeted therapy or immunotherapy for first-line treatment of adults with advanced RCC. We excluded trials evaluating only interleukin-2 versus interferon-alpha as well as trials with an adjuvant treatment setting. We also excluded trials with adults who received prior systemic anticancer therapy if more than 10% of participants were previously treated, or if data for untreated participants were not separately extractable.

DATA COLLECTION AND ANALYSIS

All necessary review steps (i.e. screening and study selection, data extraction, risk of bias and certainty assessments) were conducted independently by at least two review authors. Our outcomes were overall survival (OS), QoL, serious adverse events (SAEs), progression-free survival (PFS), adverse events (AEs), the number of participants who discontinued study treatment due to an AE, and the time to initiation of first subsequent therapy. Where possible, analyses were conducted for the different risk groups (favourable, intermediate, poor) according to the International Metastatic Renal-Cell Carcinoma Database Consortium Score (IMDC) or the Memorial Sloan Kettering Cancer Center (MSKCC) criteria. Our main comparator was sunitinib (SUN). A hazard ratio (HR) or risk ratio (RR) lower than 1.0 is in favour of the experimental arm.

MAIN RESULTS

We included 36 RCTs and 15,177 participants (11,061 males and 4116 females). Risk of bias was predominantly judged as being 'high' or 'some concerns' across most trials and outcomes. This was mainly due to a lack of information about the randomisation process, the blinding of outcome assessors, and methods for outcome measurements and analyses. Additionally, study protocols and statistical analysis plans were rarely available. Here we present the results for our primary outcomes OS, QoL, and SAEs, and for all risk groups combined for contemporary treatments: pembrolizumab + axitinib (PEM+AXI), avelumab + axitinib (AVE+AXI), nivolumab + cabozantinib (NIV+CAB), lenvatinib + pembrolizumab (LEN+PEM), nivolumab + ipilimumab (NIV+IPI), CAB, and pazopanib (PAZ). Results per risk group and results for our secondary outcomes are reported in the summary of findings tables and in the full text of this review. The evidence on other treatments and comparisons can also be found in the full text. Overall survival (OS) Across risk groups, PEM+AXI (HR 0.73, 95% confidence interval (CI) 0.50 to 1.07, moderate certainty) and NIV+IPI (HR 0.69, 95% CI 0.69 to 1.00, moderate certainty) probably improve OS, compared to SUN, respectively. LEN+PEM may improve OS (HR 0.66, 95% CI 0.42 to 1.03, low certainty), compared to SUN. There is probably little or no difference in OS between PAZ and SUN (HR 0.91, 95% CI 0.64 to 1.32, moderate certainty), and we are uncertain whether CAB improves OS when compared to SUN (HR 0.84, 95% CI 0.43 to 1.64, very low certainty). The median survival is 28 months when treated with SUN. Survival may improve to 43 months with LEN+PEM, and probably improves to: 41 months with NIV+IPI, 39 months with PEM+AXI, and 31 months with PAZ. We are uncertain whether survival improves to 34 months with CAB. Comparison data were not available for AVE+AXI and NIV+CAB. Quality of life (QoL) One RCT measured QoL using FACIT-F (score range 0 to 52; higher scores mean better QoL) and reported that the mean post-score was 9.00 points higher (9.86 lower to 27.86 higher, very low certainty) with PAZ than with SUN. Comparison data were not available for PEM+AXI, AVE+AXI, NIV+CAB, LEN+PEM, NIV+IPI, and CAB. Serious adverse events (SAEs) Across risk groups, PEM+AXI probably increases slightly the risk for SAEs (RR 1.29, 95% CI 0.90 to 1.85, moderate certainty) compared to SUN. LEN+PEM (RR 1.52, 95% CI 1.06 to 2.19, moderate certainty) and NIV+IPI (RR 1.40, 95% CI 1.00 to 1.97, moderate certainty) probably increase the risk for SAEs, compared to SUN, respectively. There is probably little or no difference in the risk for SAEs between PAZ and SUN (RR 0.99, 95% CI 0.75 to 1.31, moderate certainty). We are uncertain whether CAB reduces or increases the risk for SAEs (RR 0.92, 95% CI 0.60 to 1.43, very low certainty) when compared to SUN. People have a mean risk of 40% for experiencing SAEs when treated with SUN. The risk increases probably to: 61% with LEN+PEM, 57% with NIV+IPI, and 52% with PEM+AXI. It probably remains at 40% with PAZ. We are uncertain whether the risk reduces to 37% with CAB. Comparison data were not available for AVE+AXI and NIV+CAB.

AUTHORS' CONCLUSIONS

Findings concerning the main treatments of interest comes from direct evidence of one trial only, thus results should be interpreted with caution. More trials are needed where these interventions and combinations are compared head-to-head, rather than just to SUN. Moreover, assessing the effect of immunotherapies and targeted therapies on different subgroups is essential and studies should focus on assessing and reporting relevant subgroup data. The evidence in this review mostly applies to advanced clear cell RCC.

Cardiotoxicity of Selected Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitors in Patients with Renal Cell Carcinoma

Renal cell carcinoma (RCC) is one of the most frequent malignant neoplasms of the kidney. The therapeutic options available for the treatment of advanced or metastatic RCC include vascular endothelial growth factor receptor (VEGFR)-targeted molecules, for example, tyrosine kinase inhibitors (TKI). Various VEGFR-TKIs proved to be effective in the treatment of patients with solid tumours. The combination of two drugs may prove most beneficial in the treatment of metastatic RCC; however, it also enhances the risk of toxicity compared to monotherapy. Specific VEGFR-TKIs (e.g., sunitinib, sorafenib or pazopanib) may increase the rate of cardiotoxicity in metastatic settings. VEGF inhibitors modulate multiple signalling pathways; thus, the identification of the mechanism underlying cardiotoxicity appears challenging. VEGF signalling is vital for the maintenance of cardiomyocyte homeostasis and cardiac function; therefore, its inhibition can be responsible for the reported adverse effects. Disturbed growth factor signalling pathways may be associated with endothelial dysfunction, impaired revascularization, the development of dilated cardiomyopathy, cardiac hypertrophies and altered peripheral vascular load. Patients at high cardiovascular risk at baseline could benefit from clinical follow-up in the first 2-4 weeks after the introduction of targeted molecular therapy; however, there is no consensus concerning the surveillance strategy.

Clinical use of vascular endothelial growth factor receptor inhibitors for the treatment of renal cell carcinoma

In recent years, there have been increased incidences of metastatic renal cell carcinoma (RCC), which is refractory to conventional chemotherapy. Owing to the insensitivity to traditional therapy, targeted therapy becomes a possible alternative strategy. Over the past decade, the development of targeted treatments for metastatic RCC has advanced considerably. Several studies have shown that the vascular endothelial growth factor pathway is an important mediator for the occurrence and development of RCC, and tyrosine kinase inhibitors (TKIs) that target vascular endothelial growth factor receptors (VEGFRs) have been considered optimal therapeutic options for RCC. Six small molecules that inhibit VEGFR1/2/3, namely, sunitinib, sorafenib, axitinib, pazopanib, cabozantinib, and lenvatinib, have been approved by the Food and Drug Administration (FDA) for the treatment of RCC. Additionally, clinical trials assessing seven TKIs that target VEGFRs are currently in progress. To some extent, these drugs improve quality of life and prolong the survival of patients. This paper presents a review of the systemic targeted therapies against VEGFRs that have been approved so far or are undergoing trials as treatments for RCC.

Targeting the Tumor Microenvironment with Immunotherapy for Genitourinary Malignancies

OPINION STATEMENT

Bacillus Calmette-Guérin in urothelial carcinoma, high-dose interleukin-2 in renal cell carcinoma, and sipuleucel-T in prostate cancer serve as enduring examples that the host immune response can be harnessed to promote effective anti-tumor immunity in genitourinary malignancies. Recently, cancer immunotherapy with immune checkpoint inhibitors has transformed the prognostic landscape leading to durable responses in a subset of urothelial carcinoma and renal cell carcinoma patients with traditionally poor prognosis. Despite this success, many patients fail to respond to immune checkpoint inhibitors and progression/relapse remains common. Furthermore, modest clinical activity has been observed with ICIs as a monotherapy in advanced PCa. As such, novel treatment approaches are warranted and improved biomarkers for patient selection and treatment response are desperately needed. Future efforts should focus on exploring synergistic and rational combinations that safely and effectively boost response rates and survival in genitourinary malignancies. Specific areas of interest include (1) evaluating the optimal sequencing, disease burden, and timing of immuno-oncology agents with other anti-cancer therapeutics and (2) validating novel biomarkers of response to immunotherapy to optimize patient selection and to identify individuals most likely to benefit from immunotherapy across the heterogenous spectrum of genitourinary malignancies.

Overview of Current and Future First-Line Systemic Therapy for Metastatic Clear Cell Renal Cell Carcinoma

OPINION STATEMENT

Treatment of metastatic clear cell renal cancer (mccRCC) has seen substantial progress over the last 20 years, with many regulatory approvals since 2006 culminating in a substantial increase to overall survival (OS). Six therapies are currently available for first-line use, with additional treatments currently being tested in this setting, some of which are expected to be approved soon based on new data from the CABOSUN and CheckMate-214 trials. Based on the available evidence, we strongly believe that vascular endothelial growth factor tyrosine kinase inhibitor (VEGF-TKI) therapy over mechanistic target or rapamycin (mTOR; formerly known as mammalian target of rapamycin) inhibitor therapy is the most effective first-line option regardless of risk category assignment. High-dose interleukin-2 (HDIL-2) therapy remains a reasonable treatment option in patients with Eastern Cooperative Oncology Group (ECOG) performance status 0-1 and have minimal comorbid conditions. In the near future, these agents are likely to be surpassed by cabozantinib and by combination immune checkpoint inhibitor therapy with nivolumab and ipilimumab. Independent review has recently confirmed superiority of first-line cabozantinib over sunitinib in a phase 2 trial of 157 patients with intermediate or poor risk mccRCC (progression-free survival [PFS] 8.6 vs 5.3 months, hazard ratio [HR] 0.48, p = 0.0008). In a separate study of 1096 patients treated with either upfront sunitinib or the combination of nivolumab and ipilimumab, those with intermediate and poor risk had significant improvement in both PFS (11.6 vs 8.4 months, HR 0.82, p = 0.0331) and OS (not reached vs 26 months, p < 0.0001). Responses were greater in patients with positive programmed death receptor ligand-1 (PD-L1) tumor staining, and pending regulatory approval may become standard of care in untreated patients with intermediate to poor risk disease with positive PD-L1 status. This likely represents the beginning of additional novel immunotherapy combinations for the first-line treatment of mccRCC.