Outcome of Patients With Metastatic Chromophobe Renal Cell Carcinoma Treated With Sunitinib

BACKGROUND

Sunitinib is a standard treatment for metastatic clear cell renal cell carcinoma (mccRCC). Data on its activity in the rare variant of metastatic chromophobe renal cell carcinoma (mchRCC), are limited. We aimed to analyze the activity of sunitinib in a relatively large and homogenous international cohort of mchRCC patients in terms of outcome and comparison with mccRCC.

METHODS

Records from mchRCC patients treated with first-line sunitinib in 10 centers across 4 countries were retrospectively reviewed. Univariate and multivariate analyses of association between clinicopathologic factors and outcome were performed. Subsequently, mchRCC patients were individually matched to mccRCC patients. We compared the clinical benefit rate, progression-free survival (PFS), and overall survival (OS) between the groups.

RESULTS

Between 2004 and 2014, 36 patients (median age, 64 years; 47% male) with mchRCC were treated with first-line sunitinib. Seventy-eight percent achieved a clinical benefit (partial response + stable disease). Median PFS and OS were 10 and 26 months, respectively. Factors associated with PFS were the Heng risk (hazard ratio [HR], 3.3; p = .03) and pretreatment neutrophil-to-lymphocyte ratio (NLR) >3 (HR, 0.63; p = .02). Factors associated with OS were the Heng risk (HR, 4.1; p = .04), liver metastases (HR, 3.8; p = .03), and pretreatment NLR <3 (HR, 0.55; p = .03). Treatment outcome was not significantly different between mchRCC patients and individually matched mccRCC patients. In mccRCC patients (p value versus mchRCC), 72% achieved a clinical benefit (p = .4) and median PFS and OS were 9 (p = .6) and 25 (p = .7) months, respectively.

CONCLUSION

In metastatic chromophobe renal cell carcinoma, sunitinib therapy may be associated with similar outcome and toxicities as in metastatic clear cell renal cell carcinoma. The Heng risk and pretreatment NLR may be associated with PFS and OS.

IMPLICATIONS FOR PRACTICE

Data on the activity of sunitinib in metastatic chromophobe renal cell carcinoma (mchRCC) are limited. This study analyzed the activity of sunitinib in a cohort of mchRCC patients. Of 36 patients with mchRCC who were treated with first-line sunitinib, 78% achieved a clinical benefit. Median PFS and OS were 10 and 26 months, respectively. Treatment outcome was not significantly different between mchRCC patients and individually matched metastatic clear cell RCC patients.

Radium-223 (Ra-223) re-treatment (Re-tx): First experience from an international, multicenter, prospective study in patients (Pts) with castration-resistant prostate cancer and bone metastases (mCRPC)

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Background: Ra-223 tx for up to 6 injections (inj) is indicated for pts with symptomatic bone metastases. Ra-223 tx beyond 6 inj has not been previously reported. Herein we report the first safety and efficacy findings of Ra-223 re-tx from an international prospective trial in mCRPC pts. Methods: Pts with CRPC with ≥ 2 bone mets who completed 6 initial Ra-223 inj with no disease progression in bone and progressed after initial tx were potentially eligible for Ra-223 re-tx, provided that hematologic (heme) parameters were adequate. No concomitant cytotoxic agents were allowed; other agents were allowed at investigator discretion. Primary objective was safety. Exploratory objectives were time to radiographic bone progression, time to ALP progression, and radiographic progression-free survival (rPFS) based on MRI/CT and bone scans performed q 3 mo. Results: 44 pts had Ra-223 re-tx, 29 (66%) completed tx with all 6 inj; median (med) number inj = 6. Med time from initial Ra-223 tx = 6 mo. Besides prior Ra-223, all pts had ≥ 2 hormonal regimens; 45% had ≥ 1 chemotherapy regimen. 32 (73%) failed novel hormonal agents, eg, abiraterone and enzalutamide. Baseline characteristics were comparable to ALSYMPCA (Table). No new safety concerns were noted; incidence of tx-emergent adverse events (TEAEs) in re-tx pts was comparable to or lower than ALSYMPCA (Table). Only 2 re-tx pts had grade 3 heme TEAEs. Only 1 pt had radiographic bone progression; med time to ALP progression was not reached. Med rPFS = 9.9 mo. Conclusions: Ra-223 re-tx was well tolerated in this highly selected population, with minimal heme toxicity, and provided continued control of disease progression in bone. Clinical trial information: NCT01934790. [Table: see text] [Table: see text]

Comparison of abiraterone acetate (Abi) versus ketoconazole (Keto) in chemotherapy-naive patients (CN-pts) with metastatic castration resistant prostate cancer (mCRPC)

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Background: Abi is a standard treatment (tx) in CN-pts with mCRPC. It is a potent and selective CYP 17 inhibitor. However, in many countries where abi has not been approved yet, keto is used as an alternative CYP 17 inhibitor. Preclinical data suggests that keto is a less specific and potent inhibitor of CYP 17. Clinical data (Peer et al, Prostate 2014) suggests that in docetaxel (D) refractory mCRPC, the outcome of abi tx may be superior to keto. However, there are limited clinical data comparing both agents in CN-pts with mCRPC. We aimed to compare the clinical effectiveness of abi vs keto in CN-pts with mCRPC, who were treated after the year 2004 (approval of D for the tx of mCRPC). Methods: Records from 72 CN-pts with mCRPC treated with abi in 5 Israeli centers were reviewed retrospectively, and matched by pre-tx risk category (favorable, intermediate, poor; Keizman, Oncologist 2012) to pts treated with keto 200 - 400 mg 3x day (international database, n = 156, from 4 centers across the US and Israel). We compared the PSA response (decrease ≥ 50% from baseline), biochemical and radiological progression free survival (PFS), and overall survival (OS) between the groups. PFS and OS were determined by Cox regression. Results: The groups were matched by pre-tx risk category (favorable, intermediate, poor; Keizman, Oncologist 2012), based on pretreatment NLR and PSA doubling time, and the prior response to a gonadotropin-releasing hormone agonist. The groups were balanced regarding age (72 abi vs 70 keto), time from primary tx to disease relapse, gleason score, pre-tx disease extent (limited-axial skeleton and/or nodal vs extensive- appendicular skeleton and/or visceral), and ECOG PS. In the groups of abi vs keto, PSA response was 75% vs 47% (OR 3.8, p = 0.04), median biochemical PFS 12 vs 6 months (HR 0.62, p = 0.03), median radiological PFS 16 vs 8 months (HR 0.54, p = 0.01), median OS not reached after a median follow-up time of 18 months vs 26 months, and tx interruption d/t adverse events 10% vs 22% (0R 0.65, p = 0.05). Conclusions: In CN-pts with mCRPC, the outcome of pts treated with abi may be superior to keto.

Imaging response during therapy (tx) with radium-223 (Ra-223) for castrate resistant prostate cancer (CRPC) with bone metastases (BM)

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Background: Ra-223 is an alpha emitter that selectively targets BM. It was shown to improve the survival of patients (pts) with CRPC and BM, and thus is approved as a standard tx for these pts. However, the imaging response during Ra-223 tx is poorly defined. We aimed to describe the imaging response in pts with CRPC and BM treated with Ra-223. Methods: We evaluated the CT and bone scans response among pts with CRPC and BM, who were treated with Ra-223. Tx consisted of an injection administered q 4 weeks up to 6 injections. Scans were done at baseline, after 3 injections, and upon completion of 6 injections. Logistic regression model was used to analyze clinicopathologic factors associated with scans response. Results: 51 pts were included (median age 72). 59% (n = 30) were treated post docetaxel chemotherapy. 47% (n = 24) were treated concomitantly with a systemic standard therapy (e.g enzalutamide or abiraterone). 76% (n = 39) completed the planned 6 injections. A clinical benefit (improvement of skeletal pain and performace status) was noted in 67% (n = 34). 53% (n = 27) had a decrease of alkaline phosphatase. The response of bone metastatic disease (number of lesions) at 3 months was improvement in 22% (n = 11), stable in 53% (n = 27), and progression in 25% (n = 13). 1/13 (8%) pts evaluated at 6 months, had a progression of BM versus the 3 months status. Progression (RECIST ) of extraskeletal sites (lymph nodes, lungs, liver, adrenal) at 3 months was noted in 35% (n = 18). Concurrent systemic standard therapy (e.g enzalutamide or abiraterone) (OR 3.3, p = 0.04), Pre-tx PSADT ≥ 3 months (OR 2.62, p = 0.02) and on treatment stable/decreasing LDH (OR 2.9, p = 0.05) were associated with on treatment stable extraskeletal metastatic disease. Conclusions: Progression of BM during Ra-223 was uncommon. A bone flare may be noted during the first 3 months, and should not be confused with BM progression. Clinician should consider repeating a CT scan at 3 months in pts with short pre-tx PSADT, and LDH increase during tx, to exclude extraskeletal metastatic disease progression.

Comparison of sunitinib (su) versus temsirolimus (tem) in patients (pts) with poor-risk metastatic renal cell carcinoma (prmRCC)

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Background: Based on a single phase 3 study, the mTOR inhibitor tem was approved as 1st line therapy for prmRCC. However, in daily practice, prmRCC pts are often treated with the VEGFR and PDGFR inhibitor su. We aimed to compare the clinical effectiveness of su vs tem in prmRCC pts. Methods: We performed an international multicenter retrospective study of pts with prmRCC (HENG criteria), who were treated in 8 centers across 2 different countries. 31 pts were treated with 1st line tem. Each tem treated pt was individually matched with a 1st line su treated pt, by clinicopathologic factors. The effect of tx type (tem vs su) on clinical benefit, progression free survival (PFS) and overall survival (OS), was tested using a chi-square test and partial likelihood test from cox model. Furthermore, univariate and multivariate analyses of association between clinicopathologic factors and tx type (tem vs su), and outcome were performed using the entire pt cohort (n=62). Results: The groups were matched by age (median 65), gender (male 68%), prior nephrectomy (58%), renal cell carcinoma histology (clear cell 81%), smoking status (active in 35%), use of angiotensin system inhibitors (42%), and pre-tx neutrophil to lymphocyte ratio >3 (58%). In tem vs su treated pts, clinical benefit (partial response + stable disease) was 61% (n=19) (partial response 6%, n=2) vs 71% (n=22) (partial response 29%, n=9) (p=0.62). Median PFS was 5 vs 8 mos (p=0.08), and median OS 9 vs 17 mos (p=0.03). In multivariate analyses of the entire pt cohort (n=62), su tx was independently associated with OS (HR 0.6, p=0.001). Conclusions: In prmRCC patient, the VEGFR inhibitor su may be associated with an improved outcome vs the mTOR inhibitor tem.

Outcome of octogenarian versus (vs) young patients (pts) with metastatic renal cell carcinoma (mRCC), treated with sunitinib (su)

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Background: Su is a standard treatment (tx) for mRCC. Octogenarian pts (aged ≥ 80) are often considered to be unfit for su tx, and recommendations for their tx is limited by the paucity of clinical trials data in this population. We aimed to study baseline characteristics and outcome of octogenarian vs young (aged ≤45) pts with mRCC treated with su. Methods: We performed an international multicenter retrospective study of pts with mRCC, who were treated with su in 8 centers across 2 different countries. We compared baseline characteristics and outcome of octogenarian versus young pts. The effect of very old age on response rate (RR), progression free survival (PFS) and overall survival (OS), was tested with adjustment of other known confounding risk factors using a chi-square test and partial likelihood test from cox model. Furthermore, univariate and multivariate analyses of association between clinicopathologic factors and age, and outcome were performed using the entire pt cohort. Results: Between 2004-2013, 36 octogenarian (group 1; median age 83) and 37 young (group 2; median age 42) mRCC were treated with su. The groups were balanced regarding the following baseline clinicopathologic characteristics: gender, HENG risk, past nephrectomy, mRCC histology, ≥ 2 metastatic sites, lung/liver/bone metastasis, prior targeted tx, smoking status, use of angiotensin system inhibitors (ASIs), pre-tx neutrophil to lymphocyte ratio (NLR) >3, and sunitinib induced hypertension (HTN). In group 1 vs 2, 53% vs 27% (p=0.006) had dose reduction/treatment interruption d/t side effects. Clinical benefit (partial response + stable disease) in group 1 vs 2 was 76% vs 84%, while 24% vs 16% had disease progression within the first 3 months of tx (p=0.09). Median PFS was 11 vs 8 months (p=0.1). Median OS was 22 vs 20 months (p=0.7). In multivariate analyses of the entire pt cohort (n=73), age was not significantly associated with PFS or OS. Conclusions: Su is active in octogenarian mRCC pts. Vs young pts, a significantly higher proportion of octogenarian pts had dose reduction/treatment interruption d/t side effects.

Is there a "Trial Effect" on Outcome of Patients with Metastatic Renal Cell Carcinoma Treated with Sunitinib?

Purpose

Studies suggested the existence of a ‘trial effect', in which for a given treatment, participation in a clinical trial is associated with a better outcome. Sunitinib is a standard treatment for metastatic renal cell carcinoma (mRCC). We aimed to study the effect of clinical trial participation on the outcome of mRCC patients treated with sunitinib, which at present, is poorly defined.

Materials and Methods

The records of mRCC patients treated with sunitinib between 2004-2013 in 7 centers across 2 countries were reviewed. We compared the response rate (RR), progression free survival (PFS), and overall survival (OS), between clinical trial participants (n=49) and a matched cohort of non-participants (n=49) who received standard therapy. Each clinical trial participant was individually matched with a non-participant by clinicopathologic factors. PFS and OS were determined by Cox regression.

Results

The groups were matched by age (median 64), gender (male 67%), Heng risk (favorable 25%, intermediate 59%, poor 16%), prior nephrectomy (92%), RCC histology (clear cell 86%), pre-treatment NLR (>3 in 55%, n=27), sunitinib induced hypertension (45%), and sunitinib dose reduction/treatment interruption (41%). In clinical trial participants versus non-participants, RR was partial response/stable disease 80% (n=39) versus 74% (n=36), and progressive disease 20% (n=10) versus 26% (n=13) (p=0.63, OR 1.2). The median PFS was 10 versus 11 months (HR=0.96, p=0.84), and the median OS 23 versus 24 months (HR=0.97, p=0.89).

Conclusions

In mRCC patients treated with sunitinib, the outcome of clinical trial participants was similar to that of non-participants who received standard therapy.