Switch to generic formulation of temozolomide results in statistically significant increase in grade 3 and 4 bone marrow toxicity in glioma patients in the province of Alberta.

Background: Temozolomide (TMZ) is an oral, systemic chemotherapy used chiefly for treating high-grade glioma. Due to the rising costs of systemic chemotherapy, many jurisdictions have replaced brand name with generic formulations. The aim of this study was to determine whether or not there was difference in the incidence of grade 3 or 4 bone marrow toxicity and median overall survival in patients treated with brand name versus generic TMZ in the province of Alberta, Canada. The province suspended the use of generic TMZ based on preliminary data pointing to excess toxicity. Methods: This multicenter, retrospective study included data from patients with newly diagnosed high-grade glioma that received treatment with TMZ in Alberta. Multivariate logistic regression analysis was performed to determine the association between grade 3 or 4 toxicity to generic versus brand name TMZ exposure, ECOG score, and age. Kaplan-Meier survival estimates and log-rank testing were used to determine differences in overall survival between the brand name and generic TMZ cohorts, as well as the cytopenic versus non-cytopenic patients. Furthermore, a screening analysis for grade 3 or 4 bone marrow toxicity was conducted on all de novo glioma patients treated with brand name TMZ after Alberta preemptively stopped generic TMZ. Results: Grade 3 or 4 neutropenia and thrombocytopenia were observed in 15% and 19% of patients treated with generic TMZ (n = 156) as compared to 3% and 5% of patients (n = 100) treated with brand name TMZ-treated patients; P= .003 and .001. A trend toward increased median overall survival in glioblastoma patients treated with generic TMZ (13.7 months) versus brand name (15.8 months, P = .178.) was also observed through meeting statistical significance. Based on these results, the province stopped the use of generic TMZ and reverted to the Merck TMZ. An initial review of all new glioma patients (n = 89) treated with Merck TMZ since the province stopped the generic drug demonstrated 3.4% and 10.1% grade 3 or 4 neutropenia, respectively. Conclusions: The statistically significant difference in toxicity profile has prompted the province of Alberta to replace generic TMZ with brand name TMZ in high-grade glioma patients pending more detailed analysis. Our study provides evidence supporting the importance of conducting prospective studies on long-term safety for generic chemotherapies.

Adjuvant Systemic Therapies for Resected Stages III and IV Melanoma: A Multi-Center Retrospective Clinical Study.

BACKGROUND: Adjuvant therapies have been approved for resected melanoma based on improved recurrence-free survival. We present early findings from a real-world study on adjuvant treatments for melanoma. METHODS: A comprehensive chart review was conducted for patients receiving adjuvant systemic therapy for resected high-risk stages III and IV melanoma. Statistical analysis was performed to assess recurrence-free survival and subgroup differences. RESULTS: A total of 149 patients (median age = 58.0 years, 61.1% men, 49.7% with BRAF V600E/K genotypes) were included, with 94.6% having resected stage III melanoma. Anti-PD-1 immunotherapy was received by 86.5% of patients, while 13.4% received BRAF-targeted therapy. At a median follow-up of 22.4 months, the recurrence rate was 31.5%, with 1-year and 2-year recurrence-free survival rates of 79% and 62%, respectively. Similar recurrence rates were observed between anti-PD-1 immunotherapy and BRAF-targeted therapy. Long-term toxicity affected 27.4% of patients, with endocrinopathies and late-emergent immune-related adverse events being common. CONCLUSIONS: Real-world adjuvant systemic therapy aligns with clinical trial practice. Recurrence rates remain high despite treatment, and long-term toxicities, including endocrinopathies and chronic inflammatory conditions, are not uncommon.

Comparing the associations between host and tumor factors with survival outcomes with anti-PD-1 immunotherapy in metastatic melanoma.

BACKGROUND: Anti-programmed death-1 (PD-1) immunotherapy has drastically improved survival for metastatic melanoma; however, 50% of patients have progression within 6 months despite treatment. In this study, we investigated host, and tumor factors for metastatic melanoma patients treated with anti-PD-1 immunotherapy. METHODS: Patients treated with the anti-PD-1 immunotherapy between 2014 and 2017 were identified in Alberta, Canada. All patients had Stage IV melanoma. Patient characteristics, investigations, treatment, and clinical outcomes were obtained from electronic medical records. RESULTS: We identified 174 patients treated with anti-PD-1 immunotherapy. At 37.1 months median follow-up time 135 (77.6%) individuals had died and 150 (86.2%) had progressed. An elevated lactate dehydrogenase (LDH) had a response rate of 21.0% versus 41.0% for those with a normal LDH (p = 0.017). Host factors associated with worse median progression-free survival (mPFS) and median overall survival (mOS) included liver metastases, >3 sites of disease, elevated LDH, thrombocytosis, neutrophilia, anemia, lymphocytopenia, and an elevated neutrophil/lymphocyte ratio. Primary ulcerated tumors had a worse mOS of 11.8 versus 19.3 months (p = 0.042). We identified four prognostic subgroups in advanced melanoma patients treated with anti-PD-1 therapy. (1) Normal LDH with <3 visceral sites, (2) normal LDH with ≥3 visceral sites, (3) LDH 1-2x upper limit of normal (ULN), (4) LDH ≥2x ULN. The mPFS each group was 14.0, 6.5, 3.3, and 1.9 months, while the mOS for each group was 33.3, 15.7, 7.9, and 3.4 months. CONCLUSION: Our study reports that host factors measuring the general immune function, markers of systemic inflammation, and tumor burden and location are the most prognostic for survival.

Real-World Cabazitaxel Use and Outcomes in Metastatic Castrate-Resistant Prostate Cancer: The Impact of Response to First ARPI.

BACKGROUND: For post-docetaxel treatment of metastatic castrate-resistant prostate cancer (mCRPC), cabazitaxel has demonstrated superior third line PFS and OS compared to androgen receptor pathway inhibitors (ARPIs) in patients who progress within 12 months on first ARPI. The impact of first ARPI response, in particular responses beyond 12 months, on cabazitaxel outcomes in real-world populations is uncertain, as are other factors impacting cabazitaxel use. MATERIALS AND METHODS: mCRPC patients in Alberta, Canada who received docetaxel from October 1, 2012 to December 31, 2017 were included. We reviewed mCRPC therapies, correlating cabazitaxel use with patient characteristics and TROPIC trial inclusion/exclusion criteria. OS and PFS were evaluated in patients who received cabazitaxel, stratified by time to progression on first ARPI ≤ 12 months (poor ARPI responders, PAR) or >12 months (strong ARPI responders, SAR), using the Kaplan-Meier method. RESULTS: PAR patients had inferior OS compared to SAR patients (12.3 vs. 24.8 months, P < .001). OS was longer in PAR patients receiving cabazitaxel compared to those not treated with cabazitaxel (16.9 vs. 10.3 months, P = .015), but this benefit was not seen in the SAR group (17.1 vs. 32 months, P = .084). Cabazitaxel use was associated with reduced PFS first line post-docetaxel in SAR (3.5 vs. 14.7 months, P < .001) but not PAR patients. Of 592 patients, 170 (29%) received cabazitaxel post-docetaxel, compared to 280 (47%) and 250 (42%) for abiraterone and enzalutamide. 238 patients (40%) did not have a discussion of cabazitaxel documented. Cabazitaxel use was increased in patients who fit TROPIC trial criteria (P < .001). CONCLUSIONS: In a real-world mCRPC cohort, cabazitaxel use was associated with longer OS among PAR patients, but crucially not among strong ARPI responders. Cabazitaxel was used less frequently and later than ARPIs post-docetaxel. These data help support first ARPI progression time as a consideration in treatment sequencing.

A Population-Based Retrospective Study of Biliary Tract Cancers in Alberta, Canada.

Background: Biliary tract cancers (BTC) are uncommon malignancies and are underrepresented in the literature. Methods: We performed a retrospective population-based review of adult patients with biopsy-confirmed BTC in Alberta from 2000 to 2015. Demographic data, risk factors, symptoms, treatment, and staging data were collected and analyzed. Survival analyses were completed. Results: A total of 1604 patients were included in our study, of which 766 (47.8%) were male. The median age at diagnosis was 68 (range 19-99). There were 374 (23.3%) patients with resectable tumors at diagnosis versus 597 (37.2%) with unresectable tumors. Of the patients, 380 (21.5%) received chemotherapy (CT) and 81 (5.0%) underwent radiation therapy. There was a clear trend with worsening stage and performance status associated with shorter median overall survival (OS). Ampulla of Vater tumors had the best median OS (25.69 months), while intrahepatic bile duct cancers had the worst (5.78 months). First-line palliative CT regimens included gemcitabine+cisplatin (OS 14.98 months (mo), n = 212), single agent gemcitabine (OS 12.42 mo, n = 22), capecitabine (OS 8.12 mo, n = 8), and capecitabine+gemcitabine (OS 6.93 mo, n = 13). Patients with advanced or metastatic disease who received first-line gemcitabine+cisplatin had a median OS of 11.8 months (n = 119). Conclusion: BTCs have poor survival. Worse outcomes occur in higher stage and poorer Eastern Cooperative Oncology Group (ECOG) performance status patients across all tumor subtypes. Tumor resectability at diagnosis was associated with better OS. Our study supports the use of gemcitabine+cisplatin as a combination first-line palliative CT, as patients treated in Alberta have a comparable OS to that reported in the ABC-02 phase III study.

Effect of sorafenib starting dose and dose intensity on survival in patients with hepatocellular carcinoma: Results from a Canadian Multicenter Database.

BACKGROUND: Sorafenib has been shown to improve survival in patients with advanced hepatocellular carcinoma (HCC), however, full dose can be difficult to tolerate. The aim of this study was to determine whether sorafenib starting dose and mean dose intensity affect survival. METHODS: Patients treated with sorafenib for HCC from January 2008 to July 2016 in several Canadian provinces were included and retrospectively analyzed. The primary end point was overall survival (OS) of patients starting on sorafenib full dose compared to reduced dose. Secondary analysis compared OS with different mean dose-intensity groups. Survival outcomes were assessed with Kaplan-Meier curves and Cox proportional hazards models. A propensity score analysis was performed to account for treatment bias and confounding. RESULTS: Of 681 patients included, sorafenib was started at full dose in 289 patients (42%). Median survival for starting full and reduced dose was 9.4 months and 8.9 months (P = .15) respectively. After propensity score matching and adjusting for potential confounders there was still no difference in survival (HR 0.8, 95% CI, 0.61-1.06, P = .12). Almost half of the patients (45%) received a dose intensity < 50%. Median survival for mean dose intensity > 75%, 50%-75%, and < 50% were 9.5 months, 12.9 months, and 7.1 months (P = .005) respectively. In multivariable models, starting dose(HR 1.16, 95% CI 0.93-1.44, P = .180) and mean dose intensity were not associated with survival. CONCLUSIONS: Starting HCC patients on a reduced dose of sorafenib compared to full dose may not compromise survival. Mean dose-intensity of sorafenib may also not affect survival.

Second-line treatment of hepatocellular carcinoma after sorafenib: Characterizing treatments used over the past 10 years and real-world eligibility for cabozantinib, regorafenib, and ramucirumab.

BACKGROUND: The CELESTIAL, RESORCE, and REACH-2 trials showed survival benefit of cabozantinib, regorafenib, and ramucirumab, respectively, in hepatocellular carcinoma (HCC) patients treated with sorafenib who had good performance status (ECOG 0-1) and liver function (Child-Pugh-A). This study characterizes subsequent treatments received by HCC patients after sorafenib, and determines the proportion of patients eligible for novel therapies if strict eligibility criteria (SEC) were utilized compared to more liberal modified eligibility criteria (MEC, including ECOG 2, Child-Pugh-B7). METHODS: HCC patients who received sorafenib between 2008 and 2017 were included from the Canadian HCC CHORD Database. Patients were classified as eligible or ineligible based on available CELESTIAL, RESORCE, and REACH-2 trial SEC or MEC. Median overall survival (mOS) was assessed using the Kaplan-Meier method. RESULTS: A total of 730 patients were identified; and 172 (23.6%) received subsequent treatment. Patients who received subsequent treatment had longer mOS than those who did not (12.1 vs 3.3 months; P < .001). Using SEC, only 13.1% of patients would be eligible for cabozantinib, regorafenib, or ramucirumab. Expanding eligibility to include patients who meet MEC increased the proportion of eligible patients to 31.7%. Higher ineligibility for regorafenib and ramucirumab was driven by trial-specific criteria, including sorafenib intolerance (28%) for RESORCE and AFP <400 (58.9%) for REACH-2. CONCLUSIONS: A small proportion of real-world HCC patients would be eligible for cabozantinib, regorafenib, or ramucirumab if SEC in clinical trials were followed, while more than double would be eligible if MEC were applied. Patients who received subsequent treatment had improved mOS, regardless of whether they met SEC or MEC.

Prognosis of patients with hepatocellular carcinoma treated with sorafenib: a comparison of five models in a large Canadian database.

Several systems (tumor-node-metastasis [TNM], Barcelona Clinic Liver Cancer [BCLC], Okuda, Cancer of the Liver Italian Program [CLIP], and albumin-bilirubin grade [ALBI]) were developed to estimate the prognosis of patients with hepatocellular carcinoma (HCC) mostly prior to the prevalent use of sorafenib. We aimed to compare the prognostic and discriminatory power of these models in predicting survival for HCC patients treated with sorafenib and to identify independent prognostic factors for survival in this population. Patients who received sorafenib for the treatment of HCC between 1 January 2008 and 30 June 2015 in the provinces of British Columbia and Alberta, and two large cancer centers in Toronto, Ontario, were included. Survival was assessed using the Kaplan-Meier method. Multivariate Cox regression was used to identify predictors of survival. The models were compared with respect to homogeneity, discriminatory ability, monotonicity of gradients, time-dependent area under the curve, and Akaike information criterion. A total of 681 patients were included. 80% were males, 86% had Child-Pugh class A, and 37% of patients were East Asians. The most common etiology for liver disease was hepatitis B (34%) and C (31%). In all model comparisons, CLIP performed better while BCLC and TNM7 performed less favorably but the differences were small. The utility of each system in allocating patients into different prognostic groups varied, for example, TNM poorly differentiated patients in advanced stages (8.7 months (m) (95% CI 6.5-11.5) versus 8.4 m (95% CI 7.0-9.6) for stages III and IV, respectively) while ALBI had excellent discrimination of early grades (15.6 m [95% CI 13.0-18.4] versus 8.3 m [95% CI 7.0-9.2] for grades 1 and 2, respectively). On multivariate analysis, hepatitis C, alcoholism, and prior hepatic resection were independently prognostic of better survival (P < 0.01). In conclusion, none of the prognostic systems was optimal in predicting survival in sorafenib-treated patients with HCC. Etiology of liver disease should be considered in future models and clinical trial designs.

Predictors of Pathologic Complete Response After Neoadjuvant Treatment for Rectal Cancer: A Multicenter Study.

BACKGROUND: Pathologic complete response (pCR) to neoadjuvant chemoradiation (CRT) for rectal cancer is associated with better long-term outcomes, and is used as an early indicator of response to novel agents. To assess the rate and predictors of pCR, we performed a retrospective multicenter study involving 5 Canadian cancer centers. PATIENTS AND METHODS: Cancer registries identified consecutive patients with locally advanced rectal adenocarcinoma from the Tom Baker Cancer Centre, Cross Cancer Institute, British Columbia Cancer Agency, Ottawa Hospital Cancer Centre, and the Dr H. Bliss Murphy Cancer Centre who received fluoropyrimidine-based CRT and had curative intent surgery from 2005 to 2012. Patient, tumor, and therapy characteristics were correlated with response. RESULTS: Of the 891 patients included, 885 patients had pCR data available. Of the included patients, 161 (18.2%) had a pCR to CRT, and 724 (81.8%) did not. Patients with a pCR had a lower pretreatment carcinoembryonic antigen (CEA) level, and higher hemoglobin level in univariate analysis. In multivariable analysis, statin use at baseline (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.02-2.92; P = .04), lower pretreatment CEA level (OR, 1.03; 95% CI, 1.01-1.06; P = .03), and distance closer to anal verge (OR, 1.07; 95% CI, 1.01-1.15; P = .04) were significant predictors of pCR. The 3-year disease-free survival was 86% in those with a pCR versus 62.5% in those without a pCR (P < .0001) and pCR was associated with improved overall survival (hazard ratio, 0.29; 95% CI, 0.17-0.51; P < .0001). CONCLUSION: Lower pretreatment CEA level, proximity to anal verge, and statin use are predictors of pCR in our large retrospective cohort. Clinical trials to investigate statins combined with neoadjuvant CRT might be warranted.