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determined. Recently published long-term follow-up analyses of com
binations have shed light on this aspect.
In this study, we aimed to assess the effect of combination therapies
in mRCC patients with favorable IMDC risk.
Methods
This meta-analysis complied with Preferred Reporting Items for
Systematic Reviews and Meta-Analyses guidelines [5].
Study Cohort
We searched the MEDLINE database on August 01, 2023, using the
following keywords and boolean operators: ‘((‘renal cell carcinoma’ OR
‘kidney cancer’) AND (pembrolizumab OR nivolumab OR ipilimumab
OR atezolizumab OR avelumab))’. We also assessed the congress ab
stracts to reach the latest data. The Inclusion criteria to select the
studies: (a) patients: advanced clear-cell RCC patients with favorable
IMDC risk; (b) intervention: IO-based combination therapies; (c)
comparator: sunitinib; (d) outcome: progression-free survival (PFS),
overall survival (OS), and response rates; (e) study design: phase-III
clinical trials. Pre-clinical studies, reviews, case reports, and articles
not in English were excluded from the study.
Data Extraction
According to the inclusion and exclusion criteria, two reviewers
assessed full-text articles of studies independently (H.B., E.Y.). The
following data were extracted from the articles and congress abstracts:
author names, publishing journals, the year of publication, the total
number of patients in each study, the number of male patients, median
age, the number of patients in each cancer treatment subtype, hazard
ratios (HRs) for PFS and OS, number of patients with objective response
rate (ORR) and complete remission (CR).
Assessment Quality of Included Studies
The quality of included studies was assessed independently by two
reviewers (H.B. and E.Y.) using the RevMan 5.3 meta-analysis software
(The Nordic Cochrane Centre, Copenhagen, Denmark) and in accor
dance with the recommendations of the “Cochrane Handbook for Sys
tematic Reviews of Interventions”. Sequence generation, allocation
concealment, blinding of participants and personnel, blinding of
outcome assessment, incomplete outcome data, and selective reporting
Fig. 1. PRISMA Diagram.
H. Bolek et al.
3. Cancer
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Table 1
Baseline Characteristics of the Trials.
Trials Experimental
arm and control
arm
Number
of
patients
Median
age
(range)-
years
Male
sex
(%)
Number of
patients in
intermediate-
poor
risk (%)
Number of
patients in
favorable
risk
(%)
Previous
nephrectomy
(%)
Median
follow-up
time
(months)
Median
PFS for
favorable
risk
(months)
PFS for
favorable risk
HR (95 % CI)
Median OS
for
favorable
risk
(months)
OS for
favorable risk
HR (95 % CI)
ORR in
favorable
risk (%)
CR in
favorable
risk (%)
JADAD
Score
Keynote
426 5
Pembrolizumab +
Axitinib
432 62
(30–89)
308
(71.3)
294
(68.1)
138
(31.9)
357
(82.6)
67.2 20.7 0.76
(0.57–1.02)
60.3 1.10
(0.79–1.54)
66.8 13 2
Sunitinib 429 61
(26–90)
320
(74.6)
298
(69.5)
131
(30.5)
358
(83.4)
17.9 62.4 50.4 6.1
Javelin
Renal
101*6
Avelumab
+
Axitinib
442 62
(29–83)
316
(71.5)
343
(77.6)
94
(21.3)
352
(79.6)
34.1 20.7 0.71
(0.490–1.016)
NR 0.66
(0.356–1.223)
75.5 9.6 2
Sunitinib 444 61
(27–88)
344
(77.5)
347
(78.2)
96
(21.6)
355
(80.0)
33.6 13.8 NR 45.8 5.2
CheckMate
9ER 7
Nivolumab
+
Cabozantinib
323 62
(29–90)
249
(77.1)
249
(77.1)
74
(22.9)
222
(68.7)
44 21.4 0.75
(0.50–1.13)
NR 1.07
(0.63–1.79)
66.2 13.5 2
Sunitinib 328 61
(28–86)
232
(70.7)
256
(78.0)
72
(22.0)
233
(71.0)
13.9 47.6 44.4 11.1
Cleary 8
Pembrolizumab
+
Lenvatinib
355 64
(34–88)
255
(71.8)
243
(68.4)
110
(30.8)
262
(73.8)
49.8 28.6 0.50
(0.35–0.71)
NR
0.94
(0.52–1.58)
N/A N/A 2
Sunitinib 357 61
(29–82)
275
(77.0)
229
(64.1)
124
(34.7)
275
(77)
49.4 12.9 59.9 N/A N/A
CheckMate
214 1
Nivolumab
+
Ipilimumab
550 62
(26–85)
413
(75)
425
(77.3)
125
(22.7)
453
(82.4)
67.7 12.4 1.60
(1.13–2.26)
74.1 0.94
(0.65–1.37)
29.6 12.8 3
Sunitinib 546 62
(21–85)
395
(72)
422
(77.3)
124
(22.7)
437
(80)
28.9 68.4 51.6 6.5
H.
Bolek
et
al.
4. Cancer Treatment Reviews 122 (2024) 102667
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were evaluated. The Jadad score was also computed for each study [6].
Statistical analysis
The meta-analysis was performed using the generic inverse-variance
method with a random-effects model to calculate PFS and OS risk. The
calculated effect size was the HR and its 95 % Confidence Interval (CI).
Additionally, the Mantel-Haenszel method with a random-effects model
was used to compare response rates. The calculated effect size was the
odds ratio (OR) and its 95 % CI. All analyses were done using the Review
Manager software, version 5.3 (The Nordic Cochrane Center, The
Cochrane Collaboration, Copenhagen, Denmark). The thresholds for
statistical significance for overall effect tests were 0.05, and that for the
heterogeneity tests was 0.10. The I2
coefficient was also used to quantify
the degree of heterogeneity between the studies.
Results
After doing a search based on the criteria described previously, a
total of 3092 articles were identified, and 1119 articles were evaluated
after the duplicates were removed. After excluding reviews, pre-clinical
studies, case reports, letter and commentaries, and phase I or II trials, we
assessed 10 full-text articles. Finally, 5 phase-III RCTs (CheckMate 214,
CheckMate 9 ER, CLEAR, Javelin Renal 101 and Keynote 426) were
included in the final analysis. The PRISMA diagram of search results is
shown in Fig. 1. The risk of bias of included studies is summarized by the
Jadad score and Cochrane Risk Bias Tool in Table 1 and in Fig. 2,
respectively.
Baseline Characteristics
A total of 1,088 patients (541 patients in experimental arms) with
IMDC favorable risk group were included in this meta-analysis [1,7–10].
The experimental arm of four studies were IO and TKI combinations,
while the experimental arm of one study was IO and IO combination.
All studies included in the final analysis used sunitinib in the control
arm. The baseline characteristics of the included trials are shown in
Table 1.
Survival Outcomes
Our meta-analysis showed that (Fig. 3) IO plus TKI was associated
with a 33 % risk reduction in disease progression compared to sunitinib
(HR = 0.67, 95 % CI:0.55–0.82; p < 0.001). Conversely, IO plus IO
combination had an increased risk for disease progression (HR = 1.60,
95 % CI:1.13–2.26; p = 0.008). But there was no OS benefit in the IO
plus TKI (HR = 0.99, 95 % CI:0.79–1.24; p = 0.92) and IO plus IO (HR =
0.94, 95 % CI: 0.64–1.37; p = 0.75) subgroups.
Response Rates
Data for response rates were available in four trials [1,7–9]. A clear
benefit in terms of ORR and CR was observed with the combination of
IO-TKI (Odds Ratio (OR) = 0.40, 95 % CI:0.28–0.57; p < 0.001 for ORR
and OR = 0.55, 95 % CI:0.31–0.98; p = 0.04 for CR). However, there was
no significant difference in CR when comparing IO-IO and sunitinib (OR
= 0.47, 95 % CI:0.19–1.14; p = 0.10) alone, and IO-IO was even asso
ciated with worse ORR (OR = 2.54, 95 % CI:1.51–4.27; p < 0.001).
(Fig. 4).
Discussion
The first-line treatment for mRCC underwent a major shift after the
advent of IO-based combination treatments. Combination therapies
becomes standard of care in these patients. Risk stratification has
become an integral component of the clinical and therapeutic decision-
making process in patients with mRCC. While the efficacy of IO plus IO
and IO plus TKI combinations has been clearly demonstrated in patients
with IMDC intermediate and poor risk, their effectiveness in patients
with IMDC favorable risk according to IMDC criteria remains uncertain.
The meta-analysis demonstrated that the PFS advantage observed in
patients with favorable risk was not reflected in OS [11–14]. Moreover,
the updated analysis of the studies evaluating the IO-based combina
tions did not demonstrate OS improvement in the favorable risk group.
We conducted a meta-analysis using updated data from phase III RCTs of
Food and Drug Administration-approved combinations to investigate
the efficacy of combination therapy in the IMDC favorable-risk group.
Combinations of IO plus TKIs showed a higher ORR in the favorable
risk group than sunitinib in Keynote 426 (66.8 % vs. 50.4 %), Javelin
Renal 101 (75.5 % vs. 45.8 %), and Checkmate 9 ER (66.2 % vs. 44.4 %)
trials. This meta-analysis also demonstrated a clear benefit of IO plus TKI
combination therapy in terms of ORR and CR. IO plus TKI combinations
have been associated with a 33 % risk reduction in disease progression.
Therefore, combining IO and TKI may be a reliable choice in patients
with a high tumor burden and disease-related symptoms requiring early
disease control. Considering the side effects and financial toxicity, TKI
monotherapy may be an option for first-line therapy in patients without
disease-related symptoms, low disease burden, or a long interval be
tween nephrectomy and metastasis. Furthermore, a recent analysis from
the IMDC re-defined favorable risk into two groups as very favorable and
favorable risk [15,16]. Patients with very-favorable risk mRCC have a
longer duration of initiating systemic treatment for metastatic disease
Fig. 2. Risk of Bias Assessment.
H. Bolek et al.
5. Cancer Treatment Reviews 122 (2024) 102667
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after diagnosis, do not have liver, bone, and brain metastasis, and have a
better Karnofsky performance status than those with favorable risk
[15,16]. Patients with IMDC favorable risk are heterogeneous in terms
of biological and clinical behavior; because of this reason, a patient-
based approach is essential.
VEGF plays a crucial role in tumor progression by promoting the
formation of new blood vessels and creating an immune-suppressive
environment. Inhibition of the VEGF pathway and reversal of the
immune-suppressive environment through the combined use of anti-
VEGF-TKIs and immune checkpoint inhibitors have been shown to
prolong the survival of patients with mRCC. However, the efficacy of
this dual blockade strategy in patients with favorable risk mRCC needs
further investigation. Patients with favorable risk mRCC have been
found to exhibit higher expression levels of angiogenic genes and spe
cific targets for TKIs [17]. In IMmotion 150 study, higher angiogenesis
gene signature was associated with a better response to sunitinib mon
otherapy (ORR was 46 % in AngioHigh
versus 9 % in AngioLow
) [18]. This
data further supported by biomarker analysis of Immotion 151 and
Javelin Renal 101, high angiogenic score associated with longer PFS in
sunitinib monotherapy arm [19]. As a result, the effectiveness of anti-
angiogenic therapy in these patients may be more pronounced
compared to other risk groups. Establishing the therapeutic benefit of
anti-angiogenic therapy in patients with favorable risk mRCC would
provide valuable insights for personalized treatment approaches in this
specific patient population. The findings from the Checkmate 214 study
revealed that patients with favorable risk mRCC who were treated with
sunitinib exhibited a higher ORR and longer PFS compared to those
treated with IO-IO combination. These results highlight the significant
role of anti-angiogenic therapy, such as sunitinib, in the management of
mRCC within the favorable risk group. These findings support the notion
that targeting angiogenesis plays an essential role in achieving favorable
treatment outcomes in patients with favorable risk mRCC. Under
standing the impact of anti-angiogenic therapy in this context provides
valuable insights into the optimal treatment strategies for this specific
patient population. Further investigation and validation of these results
would help establish the clinical significance of anti-angiogenic therapy
in the management of favorable risk mRCC.
In summary, the combination of IO and TKI demonstrates improved
progression-free survival (PFS) but not overall survival (OS) in the first-
line treatment of patients with IMDC favorable-risk mRCC. It is impor
tant to note that the IMDC prognostic risk model used in clinical practice
is based solely on clinical and laboratory variables, which may not fully
capture the molecular and biological heterogeneity within patients
classified in the same risk group. Although the IMDC risk score remains a
reliable tool for risk stratification in mRCC, further genomic and mo
lecular investigations are necessary to identify specific patient sub
groups that would benefit the most from combination therapies or
potentially require less intensive treatment approaches. The integration
of genomic and molecular information into risk stratification algorithms
could enhance our ability to personalize treatment decisions.
Fig. 3. Forest plot estimating progression free survival (A) and overall survival (B) in comparison of TKI combined treatment versus sunitinib in the favorable-
risk group.
H. Bolek et al.
6. Cancer Treatment Reviews 122 (2024) 102667
6
However, it is important to acknowledge certain limitations in our
study, primarily the absence of individual-level patient data. This limi
tation prevents us from conducting more detailed subgroup analyses and
personalized treatment recommendations based on specific patient
characteristics. The lack of reliable biomarkers in our current dataset
also hampers our ability to confidently differentiate between patients
who would derive substantial benefit from combination therapy and
those who might be better suited for less intensive treatment options. As
such, while our findings shed light on the efficacy of IO and TKI com
binations in IMDC favorable-risk mRCC, the absence of individual-level
data and comprehensive biomarker insights restricts the depth of our
conclusions. Further research efforts should aim to incorporate indi
vidual patient-level data and explore robust molecular biomarkers that
can enhance our ability to tailor treatment strategies and optimize
outcomes for this specific subgroup of patients.
Certainly, it would not be incorrect to say that some patients in the
favorable risk group also derive additional benefit from combination
therapy. However, it is important to acknowledge that for certain pa
tients, combination therapy may be overtreatment, and single-agent
sunitinib or even active surveillance could be sufficient. Personalized
decision-making is crucial, taking into consideration individual patient
factors such as tumor burden, comorbidities, and treatment tolerability.
Identifying reliable biomarkers that can accurately predict treatment
response and guide therapy selection remains an unmet need in this
context. Moving forward, further research efforts are warranted to
explore the molecular landscape of mRCC and identify predictive bio
markers that can help distinguish those patients who would benefit most
from combination therapy versus those who may be better suited for less
intensive treatment options.
In conclusion, while some patients in the favorable risk group may
derive additional benefits from combination therapy, the decision to
pursue such treatment should be made on an individual basis, consid
ering both clinical and molecular factors. The absence of reliable bio
markers currently hampers our ability to make this selection in a more
informed manner. Future studies focusing on the identification of robust
biomarkers are necessary to guide treatment decisions and optimize
outcomes for patients in this subgroup.
Declaration of conflicting interest
Yüksel Ürün declared research funding (Institutional and personal)
from Turkish Oncology Group. Yüksel Ürün has served on the advisory
board for Abdi-İbrahim, Astellas, AstraZeneca, Bristol Myers-Squibb,
Eczacıbası, Gilead, Janssen, Merck, Novartis, Pfizer, Roche. Yüksel
Ürün received honoraria or has served as a consultant for Abdi-İbrahim,
Astellas, Bristol Myers-Squibb, Eczacıbasi, Janssen, Merck, Novartis,
Fig. 4. Forest plot estimating objective response rate (A) and complete remission rate (B) in comparison of TKI combined treatment versus sunitinib in the favorable-
risk group.
H. Bolek et al.
7. Cancer Treatment Reviews 122 (2024) 102667
7
Pfizer, Roche.
CRediT authorship contribution statement
Hatice Bolek: Investigation, Writing – original draft, Visualization.
Emre Yekedüz: Methodology, Formal analysis, Writing – review &
editing. Yüksel Ürün: Conceptualization, Methodology, Writing – re
view & editing, Supervision.
Declaration of competing interest
The authors declare that they have no known competing financial
interests or personal relationships that could have appeared to influence
the work reported in this paper.
References
[1] Motzer RJ, McDermott DF, Escudier B, Burotto M, Choueiri TK, Hammers HJ, et al.
Conditional survival and long-term efficacy with nivolumab plus ipilimumab
versus sunitinib in patients with advanced renal cell carcinoma. Cancer 2022;128
(11):2085–97.
[2] Heng DY, Xie W, Regan MM, Warren MA, Golshayan AR, Sahi C, et al. Prognostic
factors for overall survival in patients with metastatic renal cell carcinoma treated
with vascular endothelial growth factor–targeted agents: results from a large,
multicenter study. J Clin Oncol 2009;27(34):5794–9.
[3] Heng DY, Xie W, Regan MM, Harshman LC, Bjarnason GA, Vaishampayan UN, et al.
External validation and comparison with other models of the International
Metastatic Renal-Cell Carcinoma Database Consortium prognostic model: a
population-based study. Lancet Oncol 2013;14(2):141–8.
[4] Yip SM, Wells C, Moreira R, Wong A, Srinivas S, Beuselinck B, et al. Checkpoint
inhibitors in patients with metastatic renal cell carcinoma: results from the
international metastatic renal cell carcinoma database consortium. Cancer 2018;
124(18):3677–83.
[5] Moher D, Liberati A, Tetzlaff J, Altman DG, Group* P. Preferred reporting items for
systematic reviews and meta-analyses: the PRISMA statement. Ann Internal Med.
2009;151(4):264–9.
[6] Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJM, Gavaghan DJ, et al.
Assessing the quality of reports of randomized clinical trials: is blinding necessary?
Control Clin Trials 1996;17(1):1–12.
[7] Rini BI, Plimack ER, Stus V, Gafanov R, Waddell T, Nosov D, et al. Pembrolizumab
plus axitinib versus sunitinib as first-line therapy for advanced clear cell renal cell
carcinoma: 5-year analysis of KEYNOTE-426. American Society of. Clin Oncol
2023.
[8] Haanen J, Larkin J, Choueiri T, Albiges L, Rini B, Atkins M, et al. Extended follow-
up from JAVELIN Renal 101: subgroup analysis of avelumab plus axitinib versus
sunitinib by the International Metastatic Renal Cell Carcinoma Database
Consortium risk group in patients with advanced renal cell carcinoma. ESMO open
2023;8(3):101210.
[9] Burotto M, Powles T, Escudier B, Apolo AB, Bourlon MT, Shah AY, et al. Nivolumab
plus cabozantinib vs sunitinib for first-line treatment of advanced renal cell
carcinoma (aRCC): 3-year follow-up from the phase 3 CheckMate 9ER trial.
American Society of. Clin Oncol 2023.
[10] Motzer RJ, Porta C, Eto M, Powles T, Grünwald V, Hutson TE, et al. Final
prespecified overall survival (OS) analysis of CLEAR: 4-year follow-up of lenvatinib
plus pembrolizumab (L+ P) vs sunitinib (S) in patients (pts) with advanced renal
cell carcinoma (aRCC). American Society of. Clin Oncol 2023.
[11] Manneh R, Lema M, Carril-Ajuria L, Ibatá L, Martínez S, Castellano D, et al.
Immune checkpoint inhibitor combination therapy versus sunitinib as first-line
treatment for favorable-IMDC-risk advanced renal cell carcinoma patients: a meta-
analysis of randomized clinical trials. Biomedicines 2022;10(3):577.
[12] Ciccarese C, Iacovelli R. Uncertainty Persists Regarding the Role of Immunotherapy
for Treatment of Metastatic Renal Cell Carcinoma with Favourable Prognosis. Eur
Urol 2022;S0302–2838(22):02782.
[13] Ciccarese C, Iacovelli R, Porta C, Procopio G, Bria E, Astore S, et al. Efficacy of
VEGFR-TKIs plus immune checkpoint inhibitors in metastatic renal cell carcinoma
patients with favorable IMDC prognosis. Cancer Treat Rev 2021;100:102295.
[14] Kartolo A, Holstead RG, Duran I, Robinson AG, Vera-Badillo FE. A Systematic
Review and Meta-analysis of Dual Therapy in Patients With Advanced Renal Cell
Carcinoma of Favourable Risk. Urology 2021;157:8–14.
[15] Schmidt AL, Xie W, Gan CL, Wells C, Dudani S, Donskov F, et al. The very favorable
metastatic renal cell carcinoma (mRCC) risk group: Data from the International
Metastatic RCC Database Consortium (IMDC). American Society of. Clin Oncol
2021.
[16] Yekedüz E, Karakaya S, Ertürk İ, Tural D, Uçar G, Öztaş NŞ, et al. External
Validation of a Novel Risk Model in Patients With Favorable Risk Renal Cell
Carcinoma Defined by International Metastatic Renal Cell Carcinoma Database
Consortium (IMDC): Results From the Turkish Oncology Group Kidney Cancer
Consortium (TKCC) Database. Clin Genitourin Cancer 2023;21(1):175–82.
[17] Verbiest A, Renders I, Caruso S, Couchy G, Job S, Laenen A, et al. Clear-cell renal
cell carcinoma: molecular characterization of IMDC risk groups and sarcomatoid
tumors. Clin Genitourin Cancer 2019;17(5):e981–94.
[18] McDermott DF, Huseni MA, Atkins MB, Motzer RJ, Rini BI, Escudier B, et al.
Clinical activity and molecular correlates of response to atezolizumab alone or in
combination with bevacizumab versus sunitinib in renal cell carcinoma. Nat Med
2018;24(6):749–57.
[19] Motzer RJ, Powles T, Atkins MB, Escudier B, McDermott DF, Alekseev BY, et al.
Final overall survival and molecular analysis in IMmotion151, a phase 3 trial
comparing atezolizumab plus bevacizumab vs sunitinib in patients with previously
untreated metastatic renal cell carcinoma. JAMA Oncol 2022;8(2):275–80.
H. Bolek et al.