Practice patterns and predictors of treatment intensification in patients with metastatic castration-sensitive prostate cancer.

INTRODUCTION: Treatment intensification beyond androgen deprivation therapy (ADT) has shown survival benefit in patients with metastatic castration-sensitive prostate cancer (mCSPC). There is a need to better understand how these novel treatments fit in real-world practice. METHODS: Using electronic medical records and administrative data, a population-based, retrospective cohort study of patients newly diagnosed with de novo mCSPC between 2010 and 2020 in Alberta, Canada, and initiated ADT was conducted. Treatment intensification was defined as the receipt of apalutamide, abiraterone acetate, enzalutamide, or chemotherapy (e.g., docetaxel) within 180 days of ADT initiation. RESULTS: A total of 2515 de novo mCSPC were identified, with 2098 (83%) patients initiating ADT post-diagnosis. Of those, 525 (25%) received intensification beyond ADT. The percentage of patients who were intensified was 3% in 2010-2013 and gradually increased to 67% in 2020. From 2014-2017, docetaxel was the most commonly used approach, although it was supplanted by abiraterone acetate, apalutamide and enzalutamide from 2018 onwards. In multivariable logistic regression analyses of patients diagnosed from 2014-2020, significant predictors of intensification were younger age at diagnosis, lower Charlson comorbidity index, greater number of metastatic sites, shorter time to ADT initiation, referral to a medical oncologist, transurethral resection of the prostate or radiation prior to ADT, and more recent year of diagnosis (all p<0.05). Intensification increased for patients living in rural areas and with higher disease burden in 2018+ compared to 2014-2017. CONCLUSIONS: There has been a considerable increase in the use of ADT intensification therapies that correspond with the timing of clinical trial data and approvals of novel agents.

177Lu-PSMA-617 in Metastatic Castration-Resistant Prostate Cancer: A Review of the Evidence and Implications for Canadian Clinical Practice.

Prostate-specific membrane antigen (PSMA) is highly expressed in prostate cancer and a therapeutic target. Lutetium-177 (177Lu)-PSMA-617 is the first radioligand therapy to be approved in Canada for use in patients with metastatic castration-resistant prostate cancer (mCRPC). As this treatment represents a new therapeutic class, guidance regarding how to integrate it into clinical practice is needed. This article aims to review the evidence from prospective phase 2 and 3 clinical trials and meta-analyses of observational studies on the use of 177Lu-PSMA-617 in prostate cancer and discuss how Canadian clinicians might best apply these data in practice. The selection of appropriate patients, the practicalities of treatment administration, including necessary facilities for treatment procedures, the assessment of treatment response, and the management of adverse events are considered. Survival benefits were observed in clinical trials of 177Lu-PSMA-617 in patients with progressive, PSMA-positive mCRPC who were pretreated with androgen receptor pathway inhibitors and taxanes, as well as in taxane-naïve patients. However, the results of ongoing trials are awaited to clarify questions regarding the optimal sequencing of 177Lu-PSMA-617 with other therapies, as well as the implications of predictive biomarkers, personalized dosimetry, and combinations with other therapies.

Addressing controversial areas in the management of advanced prostate cancer in Canada Areas of consensus and controversy from the third Canadian consensus forum.

INTRODUCTION: The management of prostate cancer (PCa) is rapidly evolving. Treatment and diagnostic options grow annually, however, high-level evidence for the use of new therapeutics and diagnostics is lacking. In November 2022, the Genitourinary Research Consortium held its 3rd Canadian Consensus Forum (CCF3) to provide guidance on key controversial areas for management of PCa. METHODS: A steering committee of eight multidisciplinary physicians identified topics for discussion and adapted questions from the Advanced Prostate Cancer Consensus Conference 2022 for CCF3. Questions focused on management of metastatic castration-sensitive prostate cancer (mCSPC); use of novel imaging, germline testing, and genomic profiling; and areas of non-consensus from CCF2. Fifty-eight questions were voted on during a live forum, with threshold for "consensus agreement" set at 75%. RESULTS: The voting panel consisted of 26 physicians: 13 urologists/uro-oncologists, nine medical oncologists, and four radiation oncologists. Consensus was reached for 32 of 58 questions (one ad-hoc). Consensus was seen in the use of local treatment, to not use metastasis-directed therapy for low-volume mCSPC, and to use triplet therapy for synchronous high-volume mCSPC (low prostate-specific antigen). Consensus was also reached on sufficiency of conventional imaging to manage disease, use of germline testing and genomic profiling for metastatic disease, and poly (ADP-ribose) polymerase (PARP) inhibitors for BRCA-positive prostate cancer. CONCLUSIONS: CCF3 identified consensus agreement and provides guidance on >30 practice scenarios related to management of PCa and nine areas of controversy, which represent opportunities for research and education to improve patient care. Consensus initiatives provide valuable guidance on areas of controversy as clinicians await high-level evidence.

Nivolumab in Squamous Cell Carcinomas of the Head and Neck (SCCHN): A Real-world Outcome Study in Ontario, Canada.

The CheckMate-141 trial led to the approval of nivolumab in platinum-resistant metastatic/advanced squamous cell carcinomas of the head and neck (SCCHN). We evaluated the outcomes of SCCHN patients in Ontario, Canada, treated with nivolumab through retrospective review of the provincial treatment registry. Kaplan-Meier method was used to estimate overall survival (OS) and Cox regression to evaluate the prognostic effect of selected factors. Nivolumab was used as second-line therapy after disease relapse for curative-intent platinum chemotherapy (PC) (indication 1-I1), as second-line therapy post-PC in noncurative intent (indication 2-I2), and as first-line therapy in noncurative intent due to contraindication for PC (indication 3-I3). The median OS for patients treated with nivolumab was 5.8 months (95% CI: 4.5-7.3), and the 1-year OS was 28.4% (CI: 2.10-36.1). When patients with I3 were excluded to match inclusion criteria for CheckMate-141, median OS was 4.8 months (CI: 3.6-6.7) with 1-year OS of 21.8% (14.4-30.1). Patients with lower body surface area (BSA) (<1.81) had a median OS of 3.9 months (CI: 3.1-6.7) versus 9.0 months (CI: 6.5-14.8) in those with higher BSA, hazard ratio (HR)=0.12 (CI: 0.04-0.39, P <0.001). Patients receiving nivolumab for I1 had a median OS of 7.2 months (CI 3.8-9.8) versus 11.9 months (CI: 6.2-not reached) for I3, HR=1.73 (CI: 0.94-3.16). Patients receiving nivolumab for I2 had a median OS of 3.9 months (CI: 2.9-5.4) as compared with I3, HR=3.27 (CI: 1.80-5.94). Real-world analysis of patients with advanced/metastatic SCCHN in Ontario, Canada, treated with nivolumab demonstrates poorer median OS compared with CheckMate-141 trial. Lower BSA was a predictor of poorer median OS.

Phase I Dose-Escalation Study of the Safety and Pharmacokinetics of AGS15E Monotherapy in Patients with Metastatic Urothelial Carcinoma.

PURPOSE: Effective treatment of locally advanced or metastatic urothelial carcinoma (mUC) remains an unmet need. Antibody-drug conjugates (ADC) providing targeted drug delivery have shown antitumor activity in this setting. AGS15E is an investigational ADC that delivers the cytotoxic drug monomethyl auristatin E to cells expressing SLITRK6, a UC-associated antigen. PATIENTS AND METHODS: This was a multicenter, single-arm, phase I dose-escalation and expansion trial of AGS15E in patients with mUC (NCT01963052). During dose escalation, AGS15E was administered intravenously at six levels (0.10, 0.25, 0.50, 0.75, 1.00, 1.25 mg/kg), employing a continual reassessment method to determine dose-limiting toxicities (DLT) and the recommended phase II dose (RP2D) for the dose-expansion cohort. The primary objective was to evaluate the safety and pharmacokinetics of AGS15E in patients with and without prior chemotherapy and with prior checkpoint inhibitor (CPI) therapy. Best overall response was also examined. RESULTS: Ninety-three patients were recruited, including 33 patients previously treated with CPI. The most common treatment-emergent adverse events were fatigue (54.8%), nausea (37.6%), and decreased appetite (35.5%). Peripheral neuropathy and ocular toxicities occurred at doses of ≥0.75 mg/kg. AGS15E increased in a dose-proportional manner after single- and multiple-dose administration; accumulation was low. Five DLT occurred from 0.50 to 1.25 mg/kg. The RP2D was assessed at 1.00 mg/kg; the objective response rate (ORR) was 35.7% at this dose level. The ORR in the total population and CPI-exposed subgroup were 18.3% and 27.3%, respectively. CONCLUSIONS: DLT with AGS15E were observed at 0.75, 1.00, and 1.25 mg/kg, with an RP2D of 1.00 mg/kg being determined.

Discrete-Choice Experiment to Understand the Preferences of Patients with Hormone-Sensitive Prostate Cancer in the USA, Canada, and the UK.

BACKGROUND: Treatment options for patients with metastatic hormone-sensitive prostate cancer (mHSPC) have broadened, and treatment decisions can have a long-lasting impact on patients' quality of life. Data on patient preferences can improve therapeutic decision-making by helping physicians suggest treatments that align with patients' values and needs. OBJECTIVE: This study aims to quantify patient preferences for attributes of chemohormonal therapies among patients with mHSPC in the USA, Canada, and the UK. METHODS: A discrete-choice experiment survey instrument was developed and administered to patients with high- and very-high-risk localized prostate cancer and mHSPC. Patients chose between baseline androgen-deprivation therapy (ADT) alone and experimentally designed, hypothetical treatment alternatives representing chemohormonal therapies. Choices were analyzed using logit models to derive the relative importance of attributes for each country and to evaluate differences and similarities among patients across countries. RESULTS: A total of 550 respondents completed the survey (USA, 200; Canada, 200; UK, 150); the mean age of respondents was 64.3 years. Treatment choices revealed that patients were most concerned with treatment efficacy. However, treatment-related convenience factors, such as route of drug administration and frequency of monitoring visits, were as important as some treatment-related side effects, such as skin rash, nausea, and fatigue. Patient preferences across countries were similar, although patients in Canada appeared to be more affected by concomitant steroid use. CONCLUSION: Patients with mHSPC believe the use of ADT alone is insufficient when more effective treatments are available. Efficacy is the most significant driver of patient choices. Treatment-related convenience factors can be as important as safety concerns for patients.

The Use of Salvage Chemotherapy for Patients with Relapsed Testicular Germ Cell Tumor (GCT) in Canada: A National Survey.

BACKGROUND: Although metastatic germ cell tumor (GCT) is highly curable with initial cisplatin-based chemotherapy (CT), 20-30% of patients relapse. Salvage CT options include conventional (CDCT) and high dose chemotherapy (HDCT), however definitive comparative data remain lacking. We aimed to characterize the contemporary practice patterns of salvage CT across Canada. METHODS: We conducted a 30-question online survey for Canadian medical and hematological oncologists with experience in treating GCT, assessing treatment availability, patient selection, and management strategies used for relapsed GCT patients. RESULTS: There were 30 respondents from 18 cancer centers across eight provinces. The most common CDCT regimens used were TIP (64%) and VIP (25%). HDCT was available in 13 centers (70%). The HDCT regimen used included carboplatin and etoposide for two cycles (76% in 7 centers), three cycles (6% in 2 centers), and the TICE protocol (11%, in 2 centers). "Bridging" CDCT was used by 65% of respondents. Post-HDCT treatments considered include surgical resection for residual disease (87.5%), maintenance etoposide (6.3%), and surveillance only (6.3%). CONCLUSIONS: HDCT is the most commonly used GCT salvage strategy in Canada. Significant differences exist in the treatment availability, selection, and delivery of HDCT, highlighting the need for standardization of care for patients with relapsed testicular GCT.

Genetic testing practices among specialist physicians who treat prostate cancer A Canadian, cross-sectional survey.

INTRODUCTION: In patients with prostate cancer (PCa), the identification of an alteration in genes associated with homologous recombination repair (HRR) has implications for prognostication, optimization of therapy, and familial risk mitigation. The aim of this study was to assess the genomic testing landscape of PCa in Canada and to recommend an approach to offering germline and tumor testing for HRR-associated genes. METHODS: The Canadian Genitourinary Research Consortium (GURC) administered a cross-sectional survey to a largely academic, multidisciplinary group of investigators across 22 GURC sites between January and June 2022. RESULTS: Thirty-eight investigators from all 22 sites responded to the survey. Germline genetic testing was initiated by 34%, while 45% required a referral to a genetic specialist. Most investigators (82%) reported that both germline and tumor testing were needed, with 92% currently offering germline and 72% offering tissue testing to patients with advanced PCa. The most cited reasons for not offering testing were an access gap (50%), uncertainties around who to test and which genes to test, (33%) and interpreting results (17%). A majority reported that patients with advanced PCa (74-80%) should be tested, with few investigators testing patients with localized disease except when there is a family history of PCa (45-55%). CONCLUSIONS: Canadian physicians with academic subspecialist backgrounds in genitourinary malignancies recognize the benefits of both germline and somatic testing in PCa; however, there are challenges in accessing testing across practices and specialties. An algorithm to reduce uncertainty for providers when ordering genetic testing for patients with PCa is proposed.

Use of Systemic Therapies for Treatment of Psoriasis in Patients with a History of Treated Solid Tumours: Inference-Based Guidance from a Multidisciplinary Expert Panel.

BACKGROUND: Patients with treated solid tumours (TSTs) are a highly heterogeneous population at an increased risk for malignancy compared with the general population. When treating psoriasis in patients with a history of TSTs, clinicians are concerned about the immunosuppressive nature of psoriasis therapies, the possibility of augmenting cancer recurrence/progression, and infectious complications. No direct, high-level evidence exists to address these concerns. OBJECTIVES: We aim to provide a structured framework supporting healthcare professional and patient discussions on the risks and benefits of systemic psoriasis therapy in patients with previously TSTs. Our goal was to address the clinically important question, "In patients with TSTs, does therapy with systemic agents used for psoriasis increase the risk of malignancy or malignancy recurrence?" METHODS: We implemented an inference-based approach relying on indirect evidence when direct clinical trial and real-world data were absent. We reviewed indirect evidence supporting inferences on the status of immune function in patients with TSTs. Recommendations on systemic psoriasis therapies in patients with TSTs were derived using an inferential heuristic. RESULTS: We identified five indirect indicators of iatrogenic immunosuppression informed by largely independent bodies of evidence: (1) overall survival, (2) rate of malignancies with psoriasis and systemic psoriasis therapies, (3) rate of infections with psoriasis and systemic psoriasis therapies, (4) common disease biochemical pathways for solid tumours and systemic psoriasis therapies, and (5) solid organ transplant outcomes. On the basis of review of the totality of this data, we provided inference-based conclusions and ascribed level of support for each statement. CONCLUSIONS: Prior to considering new therapies for psoriasis, an understanding of cancer prognosis should be addressed. Patients with TSTs and a good cancer prognosis will have similar outcomes to non-TST patients when treated with systemic psoriasis therapies. For patients with TSTs and a poor cancer prognosis, the quality-of-life benefits of treating psoriasis may outweigh the theoretical risks.

Patients with previously treated cancer have a higher chance of cancer recurrence compared with the general population. With cancer incidence rising worldwide, doctors across medical specialities will need to treat other medical conditions, including inflammatory diseases such as psoriasis, in these patients. Effective systemic therapies for psoriasis reduce immune cell activity. Accordingly, there are concerns that treatments for psoriasis could worsen cancer recurrence/progression and infectious complications. There is not enough quality evidence to make broad recommendations for treating other inflammatory conditions in patients with a history of cancer. To guide patient and doctor discussions, we asked: what are effective and safe treatments when patients with treated solid tumours need systemic therapy (pills or injections) for their psoriasis? We focused on patients with solid tumours and excluded blood and skin cancers. Our panel of experts, including 12 dermatologists and 3 medical oncologists, reviewed direct and indirect evidence to answer this question. Considering the totality of evidence reviewed, the expert panel drafted and rated their level of support for opinion statements on important considerations in treating patients with psoriasis who have a history of solid tumours. By making inferences on systemic psoriasis therapies in this heterogeneous population, we take the onus off individual physicians to review the indirect data. This process may help answer questions in other disease populations where direct evidence is scarce or absent. To support treatment decisions, doctors should have a guided conversation with the patient and their family on a case-by-case basis about the risks and benefits of treatment.

Real-world utilization and outcomes of docetaxel among older men with metastatic prostate cancer: a retrospective population-based cohort study in Canada.

BACKGROUND: The adoption of docetaxel for systemic treatment of metastatic prostate cancer (PCa), in both castration-sensitive (mCSPC) and castration-resistant (mCRPC) settings, is poorly understood. This study examined the real-world utilization of docetaxel in these patients and their outcomes. METHODS: A retrospective population-based study used administrative data from Ontario, Canada, to identify men aged ≥66 years who were diagnosed with de novo mCSPC or mCRPC between 2014 and 2019 and received docetaxel. The study assessed treatment tolerability and toxicity, and survival in both cohorts. Descriptive and comparative statistical analysis were conducted. RESULTS: The study identified 11.2% (399/3556) and 13.2% (203/1534) patients diagnosed with de novo mCSPC and with mCRPC who received docetaxel respectively. The median age in both cohorts was 72 years (IQR: 68-76). Overall, 43.9% (n = 175) patients with de novo mCSPC and 52.1% (n = 85) with mCRPC completed ≥6 cycles of docetaxel. Over two-fifth also needed dose adjustments in both cohorts. Hospitalization or emergency department visit for febrile neutropenia were noted in 15.8% (n = 63) of de novo mCSPC patients and similarly in 19% (n = 31) of mCRPC cohort. The median survival of PCa patients who completed ≥6 cycles of docetaxel was significantly longer relative to those who completed <4 cycles: 32.7 vs. 23.5 months (p < 0.001) for mCSPC and 20.5 vs. 10.7 (p = 0.012) for mCRPC respectively. CONCLUSIONS: In this population-based study of elderly patients with metastatic PCa, treatment with docetaxel was associated with poor tolerability and higher toxicity compared with clinical trials. Receipt of limited cycles and reduced overall dose of docetaxel were associated with inferior overall survival.

Olaparib Efficacy in Patients with Metastatic Castration-resistant Prostate Cancer and BRCA1, BRCA2, or ATM Alterations Identified by Testing Circulating Tumor DNA.

PURPOSE: The phase III PROfound study (NCT02987543) evaluated olaparib versus abiraterone or enzalutamide (control) in metastatic castration-resistant prostate cancer (mCRPC) with tumor homologous recombination repair (HRR) gene alterations. We present exploratory analyses on the use of circulating tumor DNA (ctDNA) testing as an additional method to identify patients with mCRPC with HRR gene alterations who may be eligible for olaparib treatment. PATIENTS AND METHODS: Plasma samples collected during screening in PROfound were retrospectively sequenced using the FoundationOne®Liquid CDx test for BRCA1, BRCA2 (BRCA), and ATM alterations in ctDNA. Only patients from Cohort A (BRCA/ATM alteration positive by tissue testing) were evaluated. We compared clinical outcomes, including radiographic progression-free survival (rPFS) between the ctDNA subgroup and Cohort A. RESULTS: Of the 181 (73.9%) Cohort A patients who gave consent for plasma sample ctDNA testing, 139 (76.8%) yielded a result and BRCA/ATM alterations were identified in 111 (79.9%). Of these, 73 patients received olaparib and 38 received control. Patients' baseline demographics and characteristics, and the prevalence of HRR alterations were comparable with the Cohort A intention-to-treat (ITT) population. rPFS was longer in the olaparib group versus control [median 7.4 vs. 3.5 months; hazard ratio (HR), 0.33; 95% confidence interval (CI), 0.21-0.53; nominal P < 0.0001], which is consistent with Cohort A ITT population (HR, 0.34; 95% CI, 0.25-0.47). CONCLUSIONS: When tumor tissue testing is not feasible or has failed, ctDNA testing may be a suitable alternative to identify patients with mCRPC carrying BRCA/ATM alterations who may benefit from olaparib treatment.

FRACTION-RCC: nivolumab plus ipilimumab for advanced renal cell carcinoma after progression on immuno-oncology therapy.

BACKGROUND: The role and sequencing of combination immuno-oncology (IO) therapy following progression on or after first-line IO therapy has not been well-established. The Fast Real-time Assessment of Combination Therapies in Immuno-ONcology (FRACTION) program is an open-label, phase 2 platform trial designed to evaluate multiple IO combinations in patients with advanced renal cell carcinoma (aRCC) who progressed during or after prior IO therapy. Here, we describe the results for patients treated with nivolumab plus ipilimumab. For enrollment in track 2 (reported here), patients with histologically confirmed clear cell aRCC, Karnofsky performance status ≥70%, and life expectancy ≥3 months who had previously progressed after IO (anti-programmed death 1 (PD-1), anti-programmed death-ligand 1 (PD-L1), or anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4)) therapy were eligible. Previous treatment with anti-CTLA-4 therapy plus anti-PD-1/PD-L1 therapy precluded eligibility for enrollment in the nivolumab plus ipilimumab arm. Patients were treated with nivolumab 3 mg/kg plus ipilimumab 1 mg/kg every 3 weeks for four doses, followed by nivolumab 480 mg every 4 weeks for up to 2 years or until progression, toxicity, or protocol-specified discontinuation. The primary outcome measures were objective response rate (ORR), duration of response (DOR), and progression-free survival (PFS) rate at 24 weeks. Secondary outcomes were safety and tolerability up to 2 years. Overall survival (OS) was a tertiary/exploratory endpoint. Overall, 46 patients were included with a median follow-up of 33.8 months. The ORR was 17.4% (95% CI, 7.8 to 31.4) with eight (17.4%) patients achieving partial response. Stable disease was achieved in 19 (41.3%) patients, while 14 (30.4%) had progressive disease. Median DOR (range) was 16.4 (2.1+ to 27.0+) months. The PFS rate at 24 weeks was 43.2%, and median OS was 23.8 (95% CI, 13.2 to not reached) months. Grade 3-4 immune-mediated adverse events were reported in seven (15.2%) patients. No treatment-related deaths were reported. Patients with aRCC treated with nivolumab plus ipilimumab may derive durable clinical benefit after progression on previous IO therapies, including heavily pretreated patients, with a manageable safety profile that was consistent with previously published safety outcomes. These outcomes contribute to the knowledge of optimal sequencing of IO therapies for patients with aRCC with high unmet needs. TRIAL REGISTRATION NUMBER: NCT02996110.

Recommendations for the implementation of genetic testing for metastatic prostate cancer patients in Canada.

INTRODUCTION: Genetic testing in advanced prostate cancer is rapidly moving to become standard of care. Testing for genetic alterations in genes involved in DNA repair pathways, particularly those implicated in the homologous recombination repair (HRR) pathway, in patients with metastatic prostate cancer (mPCa) can inform selection of optimal therapies, as well as provide information about familial cancer risks; however, there are currently no consistent Canadian guidelines in place for genetic testing in mPCa. METHODS: A multidisciplinary steering committee guided the process of an environmental scan to define the current landscape, as well as the perceived challenges, through interviews with specialists from 14 sites across Canada. The challenges most commonly identified include limited testing guidelines and protocols, inadequate education and awareness, and insufficient resources. Following the environmental scan, an expert multidisciplinary working group with pan-Canadian representation from medical oncologists, urologists, medical geneticists, genetic counsellors, pathologists, and clinical laboratory scientists convened in virtual meetings to discuss the challenges in implementation of genetic testing in mPCa across Canada. RESULTS: Key recommendations from the working group include implementation of germline and tumor HRR testing for all patients with mPCa, with a mainstreaming model in which non-geneticist clinicians can initiate germline testing. The working group defined the roles and responsibilities of the various healthcare providers (HCPs) involved in the genetic testing pathway for mPCa patients. In addition, the educational needs for all HCPs involved in the genetic testing pathway for mPCa were defined. CONCLUSIONS: As genetic testing for mPCa becomes standard of care, additional resources and investments will be required to implement the changes that will be needed to support the necessary volume of genetic testing, to ensure equitable access, and to provide education to all stakeholders.

Patterns of care for non-metastatic castration-resistant prostate cancer: A population-based study.

Objectives: To describe patterns of practice of PSA testing and imaging for Ontario men receiving continuous ADT for the treatment of non-metastatic castration-resistant prostate cancer (nmCRPC). Patients and Methods: This was a retrospective, longitudinal, population-based study of administrative health data from 2008 to 2019. Men 65 years and older receiving continuous androgen deprivation therapy (ADT) with documented CRPC were included. An administrative proxy definition was applied to capture patients with nmCRPC and excluded those with metastatic disease. Patients were indexed upon progression to CRPC and were followed until death or end of study period to assess frequency of monitoring with PSA tests and conventional imaging. A 2-year look-back window was used to assess patterns of care leading up to CRPC as well as baseline covariates. Results: At a median follow-up of 40.1 months, 944 patients with nmCRPC were identified. Their median time from initiation of continuous ADT to CRPC was 26.0 months. 60.7% of patients had their PSA measured twice or fewer in the year prior to index, and 70.7% patients did not receive any imaging in the year following progression to CRPC. Throughout the study period, 921/944 (97.6%) patients with CRPC progressed to high-risk (HR-CRPC) with PSA doubling time ≤ 10 months, of which more than half received fewer than three PSA tests in the year prior to developing HR-CRPC, and 30.9% received no imaging in the subsequent year. Conclusion: PSA testing and imaging studies are underutilized in a real-world setting for the management of nmCRPC, including those at high risk of developing metastatic disease. Infrequent monitoring impedes proper risk stratification, disease staging and detection of treatment failure and/or metastases, thereby delaying the necessary treatment intensification with life-prolonging therapies. Adherence to guideline recommendations and the importance of timely staging should be reinforced to optimize patient outcomes.

Disparity in public funding of systemic therapy for metastatic renal cell carcinoma in Canada.

INTRODUCTION: There have been significant advances in systemic therapies for metastatic renal cell carcinoma (mRCC). There are currently 11 drugs approved by Health Canada: sunitinib, sorafenib, pazopanib, axitinib, everolimus, temsirolimus, nivolumab, ipilimumab, cabozantinib, lenvatinib, and pembrolizumab. These novel medications have dramatically altered the prognosis and patient experience. Despite proven benefits and recommendations for funding of most of these drugs, public access has been uneven across Canadian provinces. METHODS: We describe the provincial differences and timelines in public funding for approved systemic therapies for mRCC in Canada. Drug funding data was collected from the pan-Canadian Oncology Drug Review (pCODR) database and provincial drug formularies. Missing information was obtained from provincial cancer center pharmacists or drug formulary managers. We compared these dates to data available through regulatory bodies in the U.S., Europe, and Australia. RESULTS: There have been significant differences in the dates of approval for public funding among the provinces, with lags spanning between two and 57 months. Funding approval was typically earlier in western provinces and those with denser populations, and most delayed in smaller, eastern provinces. Approval timelines in Canada were similar to those in the U.S., Europe, and Australia. CONCLUSIONS: Most drugs approved for use in mRCC are publicly funded for specific patient populations across Canada; however, we illustrate considerable disparities in public funding implementation across the Canadian provinces. These funding lags may create inequities and differences in the patient experience across the Canadian healthcare system.

Outcomes of patients with advanced non-clear cell renal cell carcinoma treated with first-line immune checkpoint inhibitor therapy.

BACKGROUND: Immune checkpoint inhibitors (ICI) have demonstrated impressive activity in metastatic clear-cell renal cell carcinoma (ccRCC) and have become standard treatment options for patients with advanced disease. Data supporting the effectiveness of ICI-based therapy in advanced non-clear cell RCC (nccRCC) is more limited. METHODS: We performed a retrospective analysis using the International Metastatic RCC Database Consortium (IMDC) to evaluate the outcomes of patients with advanced nccRCC. Patients were classified into three groups based on first-line therapy: ICI-based therapy (monotherapy or combination), vascular endothelial growth factor (VEGF) inhibitor monotherapy, or mammalian target of rapamycin (mTOR) inhibitor monotherapy. The primary outcome was overall survival (OS). Secondary outcomes were time to treatment failure (TTF) and objective response rate (ORR). We used the Kaplan-Meier method to compare OS and TTF between treatment groups and Cox proportional hazards models to adjust for prognostic covariates. RESULTS: We identified a total of 1145 patients with metastatic nccRCC. The most common subtype was papillary RCC (54.9%). For first-line therapy, 74.3% received VEGF monotherapy, 15% received mTOR monotherapy, and 10.7% received ICI-based therapy. Median OS in the ICI group was 28.6 months, versus 16.4 months in the VEGF group and 12.2 months in the mTOR group. Median TTF in the ICI group was 6.9 months, versus 5.0 months in the VEGF group and 3.9 months in the mTOR group. ORR was 27.2% in the ICI group, 14.5% in the VEGF group, and 9% in the mTOR group. After adjusting for the IMDC risk group, histological subtype, and age, the hazard ratio for OS was 0.57 (95% CI 0.42-0.78, p < 0.0001) for ICI versus VEGF and 0.50 (95% CI 0.36-0.71, p < 0.0001) for ICI versus mTOR. CONCLUSIONS: In advanced nccRCC, first-line ICI-based treatment appears to be associated with improved OS compared to VEGF and mTOR targeted therapy. These results should be confirmed in prospective randomised trials.

Impact of stereotactic body radiotherapy (SBRT) in oligoprogressive metastatic disease.

PURPOSE: There is increasing interest in using stereotactic body radiation therapy (SBRT) in areas of oligoprogressive metastatic disease (OPD). Our main objective was to investigate the impact of SBRT on overall survival (OS) and the incidence of systemic therapy treatment switches in this population. METHODS: A retrospective institutional review of patients treated with SBRT for OPD was performed. Patients were included if they received SBRT for 1-3 discrete progressing metastases, using a dose of at least 5 Gy per fraction. The study aimed to calculate progression-free survival (PFS), overall survival (OS), local control (LC), and incidence of treatment switch (TS). PFS and OS were calculated using the Kaplan-Meier methodology, while LC and TS were determined using cumulative incidence. RESULTS: Eighty-one patients with a total of 118 lesions were treated with SBRT from July 2014 to November 2020. The Median SBRT dose was 40 (18-60) Gy in 5 (2-8) fractions. Patients had primarily kidney, lung, or breast cancer. Most patients were treated with a tyrosine kinase inhibitor (TKI) (30.9%) or chemotherapy (29.6%) before OPD. The median follow-up post-SBRT was 14 months. Median OS and PFS were 25.1 (95% CI 11.2-39.1) months and 7.8 (95% CI 4.6-10.9) months, respectively. The cumulative incidence of local progression of treated lesions was 5% at 1 year and 7.3% at 2 years. Sixty patients progressed after SBRT and 17 underwent additional SBRT. Thirty-eight patients (47%) changed systemic therapy following SBRT; the cumulative incidence of TS was 28.5% at 6 months, 37.4% at 1 year, and 43.9% at 2 years. CONCLUSIONS: SBRT effectively controls locally progressing lesions but distant progression still occurs frequently. A sizeable number of patients can be salvaged by further SBRT or have minimally progressing diseases that may not warrant an immediate initiation/switch in systemic therapy. Further prospective studies are needed to validate this benefit.

Phase I pharmacokinetic study of single agent trametinib in patients with advanced cancer and hepatic dysfunction.

BACKGROUND: Trametinib is an oral MEK 1/2 inhibitor, with a single agent recommended phase 2 dose (RP2D) of 2 mg daily (QD). This study was designed to evaluate RP2D, maximum tolerated dose (MTD), and pharmacokinetic (PK) profile of trametinib in patients with advanced solid tumors who had various degrees of hepatic dysfunction (HD). METHODS: Advanced cancer patients were stratified into 4 HD groups based on Organ Dysfunction Working Group hepatic function stratification criteria: normal (Norm), mild (Mild), moderate (Mod), severe (Sev). Dose escalation was based on "3 + 3" design within each HD group. PK samples were collected at cycle 1 days 15-16. RESULTS: Forty-six patients were enrolled with 44 evaluable for safety [Norm=17, Mild=7, Mod (1.5 mg)=4, Mod (2 mg)=5, Sev (1 mg)=9, Sev (1.5 mg)=2] and 22 for PK analysis. Treatment related adverse events were consistent with prior trametinib studies. No treatment related deaths occurred. Dose limiting toxicities (DLTs) were evaluable in 15 patients (Mild=6, Mod (1.5 mg)=3, Mod (2 mg)=2, Sev (1 mg)=3 and Sev (1.5 mg)=1). One DLT (grade 3 acneiform rash) was observed in a Sev patient (1.5 mg). Dose interruptions or reductions due to treatment related adverse events occurred in 15 patients (34%) [Norm=9, 53%; Mild=2, 29%; Mod (1.5 mg)=1, 33%; Mod (2 mg)=2, 33%; Sev (1 mg)=1, 11%; Sev (1.5 mg)=1; 50%]. There were no significant differences across HD groups for all PK parameters when trametinib was normalized to 2 mg. However, only limited PK data were available for the Mod (n = 3) and Sev (n = 3) groups compared to Norm (n = 10) and Mild (n = 6) groups. Trametinib is heavily protein bound, with no correlation between serum albumin level and unbound trametinib fraction (p = 0.26). CONCLUSIONS: RP2D for trametinib in Mild HD patients is 2 mg QD. There are insufficient number of evaluable patients due to difficulty of patient accrual to declare RP2D and MTD for Mod and Sev HD groups. DLTs were not observed in the highest dose cohorts that reached three evaluable patients - 1.5 mg QD in Mod group, and 1 mg QD in Sev group. TRIAL REGISTRATION: This study was registered in the ClinicalTrials.gov website ( NCT02070549 ) on February 25, 2014. .