Understanding the Impact of Belzutifan on Treatment Strategies for Patients with VHL.

Belzutifan was recently approved for the management of Von Hippel-Lindau disease (VHL). Given the morbidity of recurrent treatment, systemic therapy to reduce or eliminate the need for surgery has been long-awaited. Herein, we sought to gain insight about future utilization by surveying VHL kidney cancer experts in the United States. A survey developed by members of the VHL Alliance (VHLA) Clinical Advisory Council was distributed to kidney cancer providers at VHLA and National Comprehensive Cancer Network (NCCN) centers. Surveys were administered on a secure web-based platform. A total of 60 respondents from 29 institutions participated. Urologists (50%) and medical oncologists (43%) represented the majority of participants. The majority (98%) of respondents anticipated that belzutifan's approval would significantly change the current treatment landscape. Most reported that therapy should be continuous (76%). There was a difference in willingness to prescribe belzutifan by specialty (38% of urologists vs 91% of medical oncologists (P = 0.02)). In individuals with renal tumors <3 cm, 36% would still recommend surveillance, while 36% would initiate belzutifan to prevent growth. In those with multifocal renal lesions and growth of a solitary tumor on belzutifan, 50% would proceed with only treatment of that site. In conclusion, VHL kidney cancer specialists anticipate a paradigm shift with the approval of belzutifan. Provider roles may change with movement away from surgical management. Opinions on treatment indications, such as when to initiate therapy and how to best salvage, vary widely and therefore collaborative efforts among experts may assist in the development of new clinical guidelines.

Comparative effectiveness of everolimus and axitinib as second targeted therapies for metastatic renal cell carcinoma in the US: a retrospective chart review.

Background Second targeted therapies for metastatic renal cell carcinoma (mRCC) include mammalian target of rapamycin inhibitors (mTORis) and tyrosine kinase inhibitors (TKIs). This observational study compares overall survival (OS) and progression-free survival (PFS) of patients treated with everolimus (an mTORi) and axitinib (a TKI) following first TKI, and assesses the impact of type and duration of first TKI on the relative effectiveness of these second targeted therapies. Methods Retrospective reviews of medical records were conducted by medical oncologists or hematologists/oncologists recruited from a nationwide panel. Included patients with mRCC were required to have discontinued a first TKI (sunitinib, sorafenib, or pazopanib) for medical reasons, and to have initiated everolimus or axitinib as second targeted therapy between February 2012 and January 2013. OS and PFS were compared between patients treated with everolimus vs. axitinib using multivariable Cox proportional hazards regression models. Comparative results were also stratified by type and duration of first TKI. Results Included patients (n = 325 for everolimus and n = 127 for axitinib) had a mean age of 61 years and 31% were female. Sunitinib was the most commonly used first TKI (73%). After adjusting for patient characteristics, no statistically significant differences were observed in OS or PFS between everolimus and axitinib. When stratifying by type and duration of first TKI, there was no statistically significant difference in OS between everolimus and axitinib in all subgroups except for patients with <6 months on sunitinib or sorafenib as first TKI. No significant difference in PFS was observed in any subgroup. Limitations Important limitations include potential missing or inaccurate data in medical charts, and confounding due to unobserved factors. Conclusions In this retrospective chart review, no significant differences were detected in OS or PFS between axitinib and everolimus as second targeted therapy. Longer duration of first TKI was not associated with increased effectiveness of subsequent axitinib compared to everolimus.

Real-world dosing and drug costs with everolimus or axitinib as second targeted therapies for advanced renal cell carcinoma: a retrospective chart review in the US.

OBJECTIVE: To describe dosing patterns and to compare the drug costs per month spent in progression-free survival (PFS) among patients with advanced renal cell carcinoma (aRCC) treated with everolimus or axitinib following a first tyrosine kinase inhibitor (TKI). METHODS: A medical record retrospective review was conducted among medical oncologists and hematologists/oncologists in the US. Patient eligibility criteria included: (1) age ≥18 years; (2) discontinuation of first TKI (sunitinib, sorafenib, or pazopanib) for medical reasons; (3) initiation of axitinib or everolimus as a second targeted therapy during February 2012-January 2013. Real-world dosing patterns were summarized. Dose-specific drug costs (as of October 2014) were based on wholesale acquisition costs from RED BOOK Online. PFS was compared between everolimus and axitinib using a multivariable Cox proportion hazards model. Everolimus and axitinib drug costs per month of PFS were compared using multivariable gamma regression models. RESULTS: A total of 325 patients received everolimus and 127 patients received axitinib as second targeted therapy. Higher proportions of patients treated with axitinib vs everolimus started on a higher than label-recommended starting dose (14% vs 2%) or experienced dose escalation (11% vs 1%) on second targeted therapy. The PFS did not differ significantly between patients receiving everolimus or axitinib (adjusted hazard ratio (HR) = 1.16; 95% confidence interval [CI] = 0.73-1.82). After baseline characteristics adjustment, axitinib was associated with 17% ($1830) higher drug costs per month of PFS compared to everolimus ($12,467 vs $10,637; p < 0.001). LIMITATIONS: Retrospective observational study design and only drug acquisition costs considered in drug costs estimates. CONCLUSIONS: Patients with aRCC receiving axitinib as second targeted therapy were more likely to initiate at a higher than label-recommended dose and were more likely to dose escalate than patients receiving everolimus. With similar observed durations of PFS, drug costs were significantly higher-by 17% per month of PFS-with axitinib than with everolimus.

The impact of FGFR1 and FRS2α expression on sorafenib treatment in metastatic renal cell carcinoma.

BACKGROUND: Angiogenesis plays a role in tumor growth and is partly mediated by factors in both the fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) pathways. Durable clinical responses with VEGF tyrosine kinase inhibitors (TKIs) may be limited by intrinsic tumor resistance. We hypothesized that FGF signaling may impact clinical responses to sorafenib. METHODS: Nephrectomy material was available from 40 patients with metastatic renal cell carcinoma (RCC) enrolled in a phase II clinical trial of sorafenib ± interferon (ClinicalTrials.gov Identifier NCT00126594). Fibroblast growth factor receptor 1 (FGFR1) and fibroblast growth factor receptor substrate 2 alpha (FRS2α) expression was assessed by in situ hybridization and immunofluorescence, respectively. The relationship between fibroblast growth factor pathway marker levels and progression-free survival (PFS) was analyzed using Kaplan-Meier and Cox proportional hazards regression methods. RESULTS: Univariate analysis indicated that more intense FGFR1 staining was associated with shorter PFS (log-rank P = 0.0452), but FRS2α staining was not significantly associated with PFS (log-rank P = 0.2610). Multivariate Cox proportional hazards regression models were constructed for FGFR1 and FRS2α individually, adjusting for baseline Eastern Cooperative Oncology Group performance status, treatment arm and anemia status. When adjusted for each of these variables, the highest intensity level of FGFR1 (level 3 or 4) had increased progression risk relative to the lowest intensity level of FGFR1 (level 1) (P = 0.0115). The highest intensity level of FRS2α (level 3 or 4) had increased progression risk relative to the lowest intensity level of FRS2α (level 1) (P = 0.0126). CONCLUSIONS: Increased expression of FGFR1 and FRS2α was associated with decreased PFS among patients with metastatic RCC treated with sorafenib. The results suggest that FGF pathway activation may impact intrinsic resistance to VEGF receptor inhibition.

Outcomes of patients with metastatic renal cell carcinoma and end-stage renal disease receiving dialysis and targeted therapies: a single institution experience.

INTRODUCTION: Limited data are available regarding patients with renal cell carcinoma and ESRD treated with TTs. The objective of this study was to explore the tolerability and safety of TT in patients with mRCC and ESRD. PATIENTS AND METHODS: We retrospectively identified patients with mRCC and ESRD treated at the University of Texas M.D. Anderson Cancer Center from 2002 to 2012. Patient characteristics including demographic, histology, treatment, and adverse events are reported. Duration of treatment (TOT) was determined from date of drug initiation to discontinuation. Overall survival (OS) was determined from initiation of TT to death. Statistics are descriptive. RESULTS: Fourteen patients were identified. Ten patients had clear-cell histology and 4 had papillary histology. The median number of TTs per patient was 3 (range, 1-4) with median TOT of 28 months for all TTs. Eighty-eight percent of all toxicities were Grade 1 to 2; no Grade 4 toxicities were noted. Treatment discontinuations included 3 patients treated with sorafenib due to hand-foot syndrome, intolerable fatigue, and squamous cell skin cancer development; 2 patients treated with pazopanib due to intolerable fatigue and increased transaminase levels; and 1 patient treated with everolimus due to pneumonitis. Eight patients died from progressive disease. Median OS from initiation of TT was 28.5 months and 35 months from time of diagnosis. CONCLUSION: Toxicities were mild to moderate and consistent with those reported in previous studies. TTs appear to be safe, well tolerated and produce antitumor response in patients with mRCC and ESRD receiving dialysis.

Clinical outcomes for patients with metastatic renal cell carcinoma treated with alternative sunitinib schedules.

PURPOSE: We identified sunitinib alternative schedules that maintained dose intensity while decreasing adverse events in patients with metastatic renal cell cancer. We also determined the impact of alternative schedules on clinical outcomes. MATERIALS AND METHODS: We retrospectively reviewed the records of patients 18 years old or older with clear cell metastatic renal cell cancer who received first line sunitinib between January 26, 2006 and March 1, 2011 at our major comprehensive cancer center. A subset of patients was switched at the first intolerable adverse event from the traditional schedule of 28 days on and 14 days off to a schedule of 14 days on and 7 days off or other alternative schedules. A control group underwent standard dose reduction. We estimated progression-free and overall survival by the Kaplan-Meier method. Predictors of progression-free and overall survival were analyzed using Cox regression. RESULTS: A total of 187 patients were included in analysis, of whom 87% were on the traditional schedule at baseline. During treatment 53% of patients continued on the traditional schedule and 47% began or were transitioned to alternative schedules. Baseline characteristics were similar. Adverse events prompting schedule modification included fatigue in 64% of cases, hand-foot syndrome in 38% and diarrhea in 32%. Median time to alternative schedules was 5.6 months. Median overall survival was 17.7 months (95% CI 10.8-22.2) on the traditional schedule compared to 33.0 months (95% CI 29.3-not estimable) on alternative schedules (p <0.0001). On multivariable analysis poor Eastern Cooperative Oncology Group (ECOG) performance status, increased lactate dehydrogenase, decreased albumin, unfavorable Heng criteria and the traditional schedule were associated with decreased overall survival (p <0.05). CONCLUSIONS: Sunitinib administered on alternative schedules may mitigate adverse events while achieving outcomes comparable to those of the traditional schedule in patients with metastatic renal cell cancer. Prospective investigations of alternate dosing schemas are warranted.

Molecular markers to predict response to therapy.

Currently approved treatments for metastatic renal cell carcinoma (RCC) include vascular endothelial growth factor (VEGF)-blocking agents, mammalian target of rapamycin (mTOR) inhibitors, and cytokine therapy. In the near future, we are likely to add immune checkpoint blocking agents to this list. As we develop treatment platforms around each therapeutic class, determining which drug is best for a particular patient becomes increasingly important. At this point, we do not have validated predictive biomarkers for patients with RCC. Here, we discuss the logistical challenges surrounding biomarker development, summarize the current crop of biomarker candidates, and explore potential avenues for the development of more effective predictive tools for patients with advanced RCC.

Upfront, randomized, phase 2 trial of sorafenib versus sorafenib and low-dose interferon alfa in patients with advanced renal cell carcinoma: clinical and biomarker analysis.

BACKGROUND: The objective of this study was to independently evaluate the objective response rate of sorafenib and sorafenib plus low-dose interferon-alfa 2b (IFN) as frontline therapy in patients with metastatic renal cell carcinoma (mRCC). METHODS: Untreated patients with clear cell mRCC were randomized to receive sorafenib 400 mg orally twice daily or sorafenib 400 mg orally twice daily plus subcutaneous IFN 0.5 million U (MU) twice daily. Primary endpoints included the objective response rate (ORR) and safety. Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Exploratory endpoints included the predictive value of tumor tissue biomarkers. RESULTS: Eighty patients were enrolled. The median follow-up was 19.7 months (range, 0-34.2 months). The ORR was 30% (95% confidence interval [CI], 16.6%-46.5%) in the sorafenib arm and 25% (95% CI, 12.7%-41.2%) in the combination arm. The median PFS was 7.39 months in the sorafenib-alone arm (95% CI, 5.52-9.20 months) and 7.56 months in the sorafenib plus IFN arm (95% CI, 5.19-11.07 months). The median OS was 27.04 months in the combination arm (95% CI, from 22.31 to not attained) and was not reached in the sorafenib arm. Toxicities were comparable in both arms. In a multivariate model, increased phosphorylated protein kinase B (pAKT) levels were associated with poorer PFS (hazard ratio, 1.04; 95% CI, 1.00-1.08; P = .0411) and OS (hazard ratio, 1.15; 95% CI, 1.02-1.29; P = .0173). CONCLUSIONS: The addition of low-dose IFN to sorafenib resulted in efficacy outcomes that were comparable to those achieved with sorafenib monotherapy. The current results indicated that pAKT levels may predict for clinical outcome, but further mechanistic study is required.

Prospective assessment of systemic therapy followed by surgical removal of metastases in selected patients with renal cell carcinoma.

OBJECTIVE: To prospectively establish objective selection criteria for metastasectomy in patients with metastatic renal cell carcinoma (mRCC). PATIENTS AND METHODS: Between 1991 and 1999, 38 patients with mRCC with responsive or stable disease after initial systemic therapy, and with potentially resectable disease, were enrolled. Patients had a metastasectomy with curative intent and received consolidative adjuvant systemic therapy. RESULTS: Of the patients enrolled, 79% had stable disease after initial systemic therapy and 21% had a partial or complete response. Most (84%) had metastasectomy of one organ site. There was surgically no evidence of disease (sNED) in 76%. Operative morbidity and mortality were acceptable and 90% of the patients received adjuvant systemic therapy. The median (95% confidence interval) survival was 4.7 (3.0-7.8) years, and the median time to progression was 1.8 (0.8-3.1) years. Eight of 38 patients (21%) remained free of disease by the end of the study. Significant predictors of outcome were lack of sNED after metastasectomy, and the presence of pulmonary metastases. The median overall survival for those who had sNED was 5.6 years, vs 1.4 years for those who did not (P < 0.001). CONCLUSIONS: Metastasectomy in patients with mRCC not progressing after systemic therapy is feasible, with acceptable morbidity. Predictive factors for long-term outcome include pulmonary metastases and sNED. Future work evaluating treatments that can convert patients into surgical candidates will increase the cure rate of patients with mRCC.

Surgical morbidity associated with administration of targeted molecular therapies before cytoreductive nephrectomy or resection of locally recurrent renal cell carcinoma.

PURPOSE: Targeted molecular therapies such as bevacizumab, sunitinib and sorafenib before surgical resection hold promise as rational treatment paradigms for patients with metastatic or locally recurrent renal cell carcinoma. To analyze the safety of this approach we evaluated surgical parameters and perioperative complications in patients treated with targeted molecular therapies before cytoreductive nephrectomy or resection of retroperitoneal renal cell carcinoma recurrence, and compared them to a matched patient cohort who underwent up-front surgical resection. MATERIALS AND METHODS: We evaluated surgical parameters and perioperative complications in 44 patients treated with targeted molecular therapies before cytoreductive nephrectomy or resection of local renal cell carcinoma recurrence, and in a matched cohort of 58 patients who underwent up-front surgery. RESULTS: Cohorts of patients treated with preoperative targeted molecular therapy and initial surgical resection were matched in terms of clinical characteristics, burden of metastatic disease and number of adverse prognostic factors. A total of 39 complications occurred in 17 (39%) patients treated with preoperative targeted molecular therapy and in 16 (28%) who underwent up-front resection (p = 0.287). There were no statistically significant differences in surgical parameters, incidence of perioperative mortality, re-exploration, readmission, thromboembolic, cardiovascular, pulmonary, gastrointestinal, infectious or incision related complications between patients treated with preoperative targeted molecular therapy and those who underwent up-front surgery. Duration, type and interval from targeted molecular therapy to surgical intervention were not associated with the risk of perioperative morbidity. CONCLUSIONS: Preoperative administration of targeted molecular therapies is safe, and does not increase surgical morbidity or perioperative complications in patients treated with cytoreductive nephrectomy or resection of recurrent retroperitoneal renal cell carcinoma.