Targeted therapy for metastatic renal cell carcinoma

BACKGROUND

Several comparative randomised controlled trials (RCTs) have been performed including combinations of tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors since the publication of a Cochrane Review on targeted therapy for metastatic renal cell carcinoma (mRCC) in 2008. This review represents an update of that original review.

OBJECTIVES

To assess the effects of targeted therapies for clear cell mRCC in patients naïve to systemic therapy.

SEARCH METHODS

We performed a comprehensive search with no restrictions on language or publication status. The date of the latest search was 18 June 2020.

SELECTION CRITERIA

We included randomised controlled trials, recruiting patients with clear cell mRCC naïve to previous systemic treatment. The index intervention was any TKI-based targeted therapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the included studies and extracted data for the primary outcomes: progression-free survival (PFS), overall survival (OS) and serious adverse events (SAEs); and the secondary outcomes: health-related quality of life (QoL), response rate and minor adverse events (AEs). We performed statistical analyses using a random-effects model and rated the certainty of evidence according to the GRADE approach.

MAIN RESULTS

We included 18 RCTs reporting on 11,590 participants randomised across 18 comparisons. This abstract focuses on the primary outcomes of select comparisons. 1. Pazopanib versus sunitinib Pazopanib may result in little to no difference in PFS as compared to sunitinib (hazard ratio (HR) 1.05, 95% confidence interval (CI) 0.90 to 1.23; 1 study, 1110 participants; low-certainty evidence). Based on the control event risk of 420 per 1000 in this trial at 12 months, this corresponds to 18 fewer participants experiencing PFS (95% CI 76 fewer to 38 more) per 1000 participants. Pazopanib may result in little to no difference in OS compared to sunitinib (HR 0.92, 95% CI 0.80 to 1.06; 1 study, 1110 participants; low-certainty evidence). Based on the control event risk of 550 per 1000 in this trial at 12 months, this corresponds to 27 more OSs (95% CI 19 fewer to 70 more) per 1000 participants. Pazopanib may result in little to no difference in SAEs as compared to sunitinib (risk ratio (RR) 1.01, 95% CI 0.94 to 1.09; 1 study, 1102 participants; low-certainty evidence). Based on the control event risk of 734 per 1000 in this trial, this corresponds to 7 more participants experiencing SAEs (95% CI 44 fewer to 66 more) per 1000 participants. 2. Sunitinib versus avelumab and axitinib Sunitinib probably reduces PFS as compared to avelumab plus axitinib (HR 1.45, 95% CI 1.17 to 1.80; 1 study, 886 participants; moderate-certainty evidence). Based on the control event risk of 550 per 1000 in this trial at 12 months, this corresponds to 130 fewer participants experiencing PFS (95% CI 209 fewer to 53 fewer) per 1000 participants. Sunitinib may result in little to no difference in OS (HR 1.28, 95% CI 0.92 to 1.79; 1 study, 886 participants; low-certainty evidence). Based on the control event risk of 890 per 1000 in this trial at 12 months, this would result in 29 fewer OSs (95% CI 78 fewer to 8 more) per 1000 participants. Sunitinib may result in little to no difference in SAEs (RR 1.01, 95% CI 0.93 to 1.10; 1 study, 873 participants; low-certainty evidence). Based on the control event risk of 705 per 1000 in this trial, this corresponds to 7 more SAEs (95% CI 49 fewer to 71 more) per 1000 participants.  3. Sunitinib versus pembrolizumab and axitinib Sunitinib probably reduces PFS as compared to pembrolizumab plus axitinib (HR 1.45, 95% CI 1.19 to 1.76; 1 study, 861 participants; moderate-certainty evidence). Based on the control event risk of 590 per 1000 in this trial at 12 months, this corresponds to 125 fewer participants experiencing PFS (95% CI 195 fewer to 56 fewer) per 1000 participants. Sunitinib probably reduces OS (HR 1.90, 95% CI 1.36 to 2.65; 1 study, 861 participants; moderate-certainty evidence). Based on the control event risk of 880 per 1000 in this trial at 12 months, this would result in 96 fewer OSs (95% CI 167 fewer to 40 fewer) per 1000 participants. Sunitinib may reduce SAEs as compared to pembrolizumab plus axitinib (RR 0.90, 95% CI 0.81 to 1.02; 1 study, 854 participants; low-certainty evidence) although the CI includes the possibility of no effect. Based on the control event risk of 604 per 1000 in this trial, this corresponds to 60 fewer SAEs (95% CI 115 fewer to 12 more) per 1000 participants.  4. Sunitinib versus nivolumab and ipilimumab Sunitinib may reduce PFS as compared to nivolumab plus ipilimumab (HR 1.30, 95% CI 1.11 to 1.52; 1 study, 847 participants; low-certainty evidence). Based on the control event risk of 280 per 1000 in this trial at 30 months' follow-up, this corresponds to 89 fewer PFSs (95% CI 136 fewer to 37 fewer) per 1000 participants. Sunitinib reduces OS (HR 1.52, 95% CI 1.23 to 1.89; 1 study, 847 participants; high-certainty evidence). Based on the control event risk 600 per 1000 in this trial at 30 months, this would result in 140 fewer OSs (95% CI 219 fewer to 67 fewer) per 1000 participants. Sunitinib probably increases SAEs (RR 1.37, 95% CI 1.22 to 1.53; 1 study, 1082 participants; moderate-certainty evidence). Based on the control event risk of 457 per 1000 in this trial, this corresponds to 169 more SAEs (95% CI 101 more to 242 more) per 1000 participants.

AUTHORS' CONCLUSIONS

Based on the low to high certainty of evidence, several combinations of immune checkpoint inhibitors appear to be superior to single-agent targeted therapy in terms of PFS and OS, and with a favourable AE profile. Some single-agent targeted therapies demonstrated a similar or improved oncological outcome compared to others; minor differences were observed for AE within this group. The certainty of evidence was variable ranging from high to very low and all comparisons were based on single trials.

Targeted therapy for advanced renal cell carcinoma

BACKGROUND

Advanced renal cell carcinoma has been resistant to drug therapy of different types and new types of drug therapy are needed. Targeted agents inhibit known molecular pathways involved in cellular proliferation and neoangiogenesis, the induction by the tumour of host microvascular networks. Angiogenesis is of special interest in the clear cell histologic subtype of renal cancer because of its vascularity and constitutively activated hypoxia-inducible path in the majority of tumours.

OBJECTIVES

1) To provide a systematic review of studies testing targeted agents.2) To identify the type and degree of clinical benefit, if any, of targeted agents over the prior standard of care, particularly any impact on overall survival.

SEARCH STRATEGY

1) Electronic search of CENTRAL, MEDLINE and EMBASE databases.2) Hand search of international cancer meeting abstract and other sources specified in the protocol.

SELECTION CRITERIA

Randomized controlled studies of targeted agents in patients with advanced renal cell cancer reporting major remission rate or overall survival by allocation. Progression-free survival (PFS) was adopted as an additional outcome because PFS was a commonly chosen primary outcome, and because several pivotal studies allowed crossover from the control to the investigational arm after closure to accrual thereby making overall survival a problematic endpoint.

DATA COLLECTION AND ANALYSIS

Nineteen fully eligible studies tested ten different targeted agents (Table 04). One additional study was excluded because no outcome data by allocation have been reported (Hutson 2007). For purposes of comparison, the studies were divided into three groups: Group 1 studies compared different doses of the same agents; Group 2 studies examined the impact of targeted agents in patients who had received prior cytokine or other systemic therapy; and Group 3 studies tested targeted agents in systemically naive patients, either against standard interferon-alfa or against another control therapy. Meta-analysis was not utilized because there were very few situations where the same agents had been tested in the same group in more than one study.

MAIN RESULTS

In systemically untreated patients in studies using subcutaneous interferon-alfa as control therapy, the major findings were: 1) An improvement in overall survival has been demonstrated only with the use of weekly intravenous temsirolimus in patients with unselected renal cancer histology and adverse prognostic features (median survival 10.9 months versus 7.3 months for temsirolimus or interferon-alfa respectively, HR 0.73, P = 0.008 log rank, Hudes 2007). However, the chance of major remission was low and not improved with temsirolimus. 2) In patients with mostly good or intermediate prognostic risk with clear cell renal cancer, oral sunitinib improves the chance of major remission, the probability of symptomatic improvement, and freedom from disease progression (Motzer 2007); in a similar setting, the addition of biweekly intravenous bevacizumab to interferon-alfa also improved the chance of major remission and prolonged progression-free survival (Escudier 2007b); overall survival had not changed at the time of interim reporting of either study. In patients with clear cell renal cancers who had failed prior cytokine therapy, oral sorafenib gives a better quality of life than placebo as well as improved chance of being free of disease progression; overall survival may have improved but is hard to evaluate because of crossover of placebo-assigned patients after the study closed to accrual (Escudier 2007a).

AUTHORS' CONCLUSIONS

Based on less than a decade of experience, some targeted agents with specified molecular targets have demonstrated clinically useful benefits over the previous standard of care for patients with advanced renal cancer. Much more research is required to fully establish the role of targeted agents in this condition.

Phase II trial of interferon and thalidomide in metastatic renal cell carcinoma

OBJECTIVES

To evaluate the toxicity and efficacy of interferon and thalidomide combination in a phase II clinical trial.

PATIENTS AND METHODS

Eligibility included metastatic renal cancer with a maximum of two prior regimens, performance status of 0-2 and adequate renal, hepatic and bone marrow function.

RESULTS

Twenty patients were enrolled on this phase II trial. Median age was 60.5 years (Range: 39-75 years). 17 patients had visceral metastases (lung/liver/both) and 3 patients had lymph node only metastases. A total of 26 cycles of 4 weeks each were administered; median of 1 cycle and range from 0-9 cycles. The therapy was poorly tolerated with grade 3 adverse events noted in 12 (60%) of the 20 patients. No objective responses were noted. Of the 14 response evaluable patients, one had an unconfirmed response (38% decrease in size) and one had prolonged disease stabilization for 10 months. The median time to progression was 1.0 month and median survival was 2.8 months. Pre and post therapy PET scans were performed nine weeks apart on one patient. The mean standardized uptake values (SUV) declined from 1.45 (SUV min-max 0.89-1.76) to 1.12 (SUV min-max 0.55-1.47), denoting anti vascular effect. The patient did not have an objective response but had a disease stabilization sustained for 10 months.

CONCLUSION

The combination of interferon and thalidomide has minimal efficacy and considerable toxicity which makes this combination unworthy of future investigation in metastatic renal cancer.

Randomized Phase II Study Comparing Thalidomide With Medroxyprogesterone Acetate in Patients With Metastatic Renal Cell Carcinoma

Purpose

To investigate escalating doses of thalidomide compared with medroxyprogesterone in patients with metastatic renal cell carcinoma (RCC), who had either progressed after first-line immunotherapy or who were not suitable for immunotherapy.

Patients and Methods

Thalidomide was started at 100 mg/d orally (PO) and escalated by 100 mg/d every 2 weeks to the maximum dose of 400 mg/d. Medroxyprogesterone was given at a fixed dose of 300 mg PO daily.

Results

Sixty patients were entered (thalidomide:medroxyprogesterone = 29:31; median age, 59 [thalidomide], 60 [medroxyprogesterone]; No. of patients assessable for response, 22 [thalidomide], 26 [medroxyprogesterone]). In the thalidomide arm, there was no objective response seen. The best response was SD in three patients lasting 5+, 6+, and 12 months, respectively. All patients in the medroxyprogesterone arm progressed. There was no difference in overall survival between the two arms; median survival in the thalidomide arm was 8.2 months compared with 4.8 months in the medroxyprogesterone arm (P = .62). Hazard ratio was 0.88 (95% CI, 0.67 to 1.94). Median duration of treatment was 73 days (range, 14 to 364 days) in the thalidomide arm, and 84 days (range, 7 to 175 days) in the medroxyprogesterone arm. The high incidence of toxicity in the thalidomide arm, mainly somnolence, constipation, fatigue and paraesthesia, meant that only 30.8% of patients were able to tolerate the maximum dose of 400 mg/d of treatment.

Conclusion

Thalidomide is not superior to medroxyprogesterone acetate in patients with metastatic RCC. Its risk/benefit ratio does not favor its use in this patient population.

Chemotherapies and immunotherapies for metastatic kidney cancer

Most patients who develop kidney cancer are effectively treated with a radical nephrectomy; however, for those patients who present with or develop metastatic disease, the therapeutic options are limited. Interferon and interleukin-2 remain the standard therapies. Several studies have identified the optimal doses and schedules of these cytokines and groups of patients most likely to benefit from immunotherapy. Although cytotoxic chemotherapy continues to have a minor role in patients with clear cell renal carcinoma, it may become the treatment of choice for some patients with variant renal cancers. Novel agents targeting the vascular endothelial growth factor, its receptor, and other hypoxia-induced proteins are showing great promise and soon may expand the therapeutic options for patients with advanced kidney cancer.

Biology and clinical development of vascular endothelial growth factor-targeted therapy in renal cell carcinoma

PURPOSE

To review the biology of renal cell carcinoma (RCC) leading to vascular endothelial growth factor (VEGF) overexpression and the clinical results of VEGF blockade in metastatic RCC.

METHODS

A review of relevant published literature regarding VEGF, von Hippel-Lindau (VHL) gene inactivation and VEGF overexpression in RCC was performed. Further, a review of the mechanism, toxicity, and clinical development of VEGF-targeted therapy in metastatic RCC was undertaken.

RESULTS

VEGF is the major proangiogenic protein that exerts a biologic effect through interaction with cellular receptors. The majority of sporadic clear-cell RCC tumors are characterized by VHL tumor suppressor gene inactivation. The resulting VHL gene silencing leads to VEGF overexpression. An antibody to VEGF (bevacizumab) has demonstrated a significant prolongation of time to disease progression compared with placebo in patients with metastatic RCC. Small molecules with inhibitory effects against the VEGF receptor have undergone initial clinical testing in metastatic RCC with substantial objective response rates.

CONCLUSION

Therapeutic targeting of VEGF in RCC has strong biologic rationale and preliminary clinical efficacy. Further investigation will determine the optimal timing, sequence, and utility of these agents in RCC.

Novel Antiangiogenic Therapies for Renal Cell Cancer

Renal cell cancer remains a disease for which highly effective therapy for the majority of patients with metastatic disease is lacking. The biology of clear cell carcinomas and their association with mutations of the von Hippel-Lindau gene and its resultant increased expression of vascular endothelial growth factor (VEGF) make angiogenesis a potentially pathophysiologic mechanism for tumor development. As a result, the use of antiangiogenic therapy is an intriguing concept for the treatment of renal cell cancer. Various agents, aside from the inhibitors of VEGF, have been studied, including thalidomide, low-dose interferon, and novel antiangiogenic agents such as the thrombospondin-1 mimetics. Use of these agents has been associated with some degree of objective response or prolonged stabilization of disease, and their true value needs to be assessed in ongoing prospective studies. Combinations of antiangiogenic agents either with other similarly acting drugs or as a component of a "cocktail" with other noncytotoxic therapies should be explored in this patient population.