Jose Gerard Monzon

Ridaforolimus: a promising drug in the treatment of soft-tissue sarcoma and other malignancies

Ridaforolimus (deforolimus; AP23573; MK-8669) is a novel sirolimus derivative manufactured by ARIAD Pharmaceuticals and acquired by Merck. It is a small-molecule kinase inhibitor of the mTOR in clinical development for the treatment of cancer. Both intravenous and oral formulations of the agent are being tested in cancer clinical trials. In preclinical and clinical studies, ridaforolimus exhibited significant antitumor activity with acceptable safety and tolerability. With single-agent ridaforolimus, mucositis and myelosuppression were dose-limiting toxicities. In advanced soft-tissue sarcoma, single-agent ridaforolimus was associated with a 29% clinical benefit rate and 2% partial response rate. A Phase III trial has recently been reported to have met its primary end point.

A phase 2 study of tremelimumab in patients with advanced uveal melanoma.

Similar to cutaneous melanoma, several strategies of immune escape have been documented in uveal melanomas (UMs). We hypothesized that these cancers could respond to cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) inhibition with tremelimumab by potentiating T-cell activation. This was an open-label, multicentre phase 2 study in patients with advanced UM who had not received prior immunotherapy. Patient received tremelimumab at 15 mg/kg administered every 90 days for up to four cycles. The primary endpoint was 6-month progression-free survival (PFS). Secondary endpoints were safety, durable response rate, objective response rate, duration of objective response, duration of complete response, and median overall survival (OS). Eleven patients, all with M1c disease, were enrolled with no responses observed. The median follow-up was 11 months (range 2–36 months). The median PFS was 2.9 months (95% confidence interval 2.8–3.0) and the 6-month PFS rate was 9.1%. The median OS was 12.8 months (95% confidence interval 3.8–19.7). Toxicities were consistent with CTLA-4 blockade and were manageable. Although the median OS of 12.8 months and the manageable toxicity profile of tremelimumab observed in this study seem promising, the modest 6-month PFS and the lack of responses observed resulted in the study being stopped due to futility at the first interim stage. To date, no systemic treatment has demonstrated a survival benefit in patients with advanced UM. The standard treatment for patients with advanced UM should be a clinical trial.

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.

Targeted agents for the treatment of metastatic melanoma

In the last year, the armamentarium of melanoma therapeutics has radically changed. Recent discoveries in melanoma biology and immunology have led to novel therapeutics targeting known oncogenes and immunotherapeutic antibodies. Phase III clinical trials of these agents have reported measurable and meaningful benefits to patients with metastatic disease. In this article, we review recent findings and discuss their significance in melanoma therapy. As our understanding of melanoma biology grows, this initial therapeutic success may be enhanced through the use of molecular markers to select patients, and new targeted immunotherapies in sequential or combination drug regimens.

Clinical outcomes of elderly patients receiving neoadjuvant chemoradiation for locally advanced rectal cancer

BACKGROUND Studies of clinical outcomes of elderly patients treated with neoadjuvant chemoradiation (nCRT) for locally advanced rectal cancer (LARC) are limited. Our aim was to assess the impact of age on clinical outcomes in a large multi-institutional database. PATIENTS AND METHODS Data for patients diagnosed with LARC who received nCRT and curative-intent surgery between 2005 and 2012 were collected from five major Canadian cancer centers. Age was analyzed as a continuous and dichotomous variable (< 70 versus ≥ 70 years) and correlated with disease-free survival (DFS), cancer-specific survival (CSS) and overall survival (OS). Cox regression models were used to adjust for important prognostic factors. RESULTS Of 1172 patients included, 295 (25%) were ≥ 70 years, and they were less likely to receive adjuvant chemotherapy (ACT; 60% versus 79%, P < 0.0001), oxaliplatin-based ACT (12% versus 31%, P < 0.0001), less likely to complete nCT (76% versus 86%, P < 0.001), and more likely to be anemic at initiation of nCRT (42% versus 30%, P = 0.0004). In multivariate analyses, age ≥ 70 years was associated with similar DFS [hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.68-1.26, P = 0.63], similar CSS (HR 0.81, 95% CI 0.46-1.41, P = 0.45), and similar OS (HR 1.28, 95% CI 0.88-1.86, P = 0.20), compared with the younger age group. As a continuous variable, increasing age was not predictive of DFS (HR 1.00, 95% CI 0.99-1.02, P = 0.49) or CSS (HR 1.002, 95% CI 0.98-1.02, P = 0.88); however, it correlated with an inferior OS (HR 1.02, 95% CI 1.00-1.03, P = 0.04). CONCLUSIONS Elderly patients (≥ 70 years) who receive nCRT followed by surgery appear to have similar outcomes compared with younger patients. Decisions regarding eligibility for nCRT and surgery should not be based on age alone.

Correlation of single arm versus randomised phase 2 oncology trial characteristics with phase 3 outcome.

BACKGROUND AND AIM The primary aim of this study was to determine whether randomised phase 2 (RP2) trials predict phase 3 trial outcome better than single arm phase 2 (SAP2) studies. Although theoretical superiority of RP2 trials has been postulated, no empiric studies have been conducted. METHODS Published phase 3 trials testing systemic cancer therapy were identified through a Medline search. Those of superiority design, which cited phase 2 trials supporting the experimental arm, were included. Trial design and outcome details were extracted. Statistical analysis was performed using the Generalized Estimating Equation method correlating phase 2 features with phase 3 outcome, accounting for any phase 3 duplication. RESULTS Of 189 eligible phase 3 trials, 18.5% were in haematological malignancies and 81.5% in solid tumors. The primary outcome was positive in 79 (41.8%). These were supported by 336 phase 2 trials (range 1-9 per phase 3 trial) including 66 RP2 trials. Positive phase 2 outcome, randomised or not, correlated with positive phase 3 outcome (p=0.03). RP2 studies were not superior to SAP2 studies at predicting phase 3 study success. Phase 2 trial features not predictive of phase 3 outcome included primary endpoint, sponsorship, sample size, similarity in patient population and therapy. CONCLUSIONS RP2 studies were not superior to SAP2 trials at predicting phase 3 study success. Further research into phase 2 trial design is required given the added resources required to conduct RP2 studies and the lack of empiric evidence supporting superiority over single arm studies.

Association Between SLC16A5 Genetic Variation and Cisplatin-Induced Ototoxic Effects in Adult Patients With Testicular Cancer.

Importance Cisplatin-induced ototoxic effects are an important complication that affects testicular cancer survivors as a consequence of treatment. The identification of genetic variants associated with this adverse drug reaction will further our mechanistic understanding of its development and potentially lead to strategies to prevent ototoxic effects. Objective To identify the genetic variants associated with cisplatin-induced ototoxic effects in adult testicular cancer patients. Design, Setting, and Participants This retrospective study was performed by the Canadian Pharmacogenomics Network for Drug Safety using patients recruited from 5 adult oncology treatment centers across Canada. Male patients who were 17 years or older, diagnosed with germ cell testicular cancer, and previously treated with cisplatin-based chemotherapy were recruited from July 2009 to April 2013 using active surveillance methodology. Cisplatin-induced ototoxic effects were independently diagnosed by 2 audiologists. Patients were genotyped for 7907 variants using a custom pharmacogenomic array. Logistic regression was used to identify genetic variants that were significantly associated with ototoxic effects. The validity of these findings was confirmed through independent replication and cell-based functional assays. Exposures Cisplatin-based chemotherapy. Main Outcomes and Measures Cisplatin-induced ototoxic effects. Results After exclusions, 188 patients (median [interquartile range] age, 31 [24-39] years) were enrolled in this study to form the discovery and replication cohorts. Association and fine-mapping analyses identified a protein-coding variant, rs4788863 in SLC16A5, that was associated with protection against cisplatin-induced ototoxic effects in 2 independent cohorts (combined cohort: odds ratio, 0.06; 95% CI, 0.02-0.22; P = 2.17 × 10−7). Functional validation of this transporter gene revealed that in vitro SLC16A5–silencing altered cellular responses to cisplatin treatment, supporting a role for SLC16A5 in the development of cisplatin-induced ototoxic effects. These results were further supported by the literature, which provided confirmatory evidence for the role that SLC16A5 plays in hearing. Conclusions and Relevance This study has identified a novel association between protein-coding variation in SLC16A5 and cisplatin-induced ototoxic effects. These findings have provided insight into the molecular mechanisms of this adverse drug reaction in adult patients with germ cell testicular cancer. Given that previous studies have shown that cimetidine, an SLC16A5-inhibitor, prevents murine cisplatin-induced ototoxic effects, the findings from this study have important implications for otoprotectant strategies in humans.

Chapter 11:Combination Agents Versus Multi-Targeted Agents – Pros and Cons

Cancer, in all its various forms, is perhaps the archetypical multi-factorial disease and it is therefore not surprising that single-target drugs are rarely useful as anti-cancer agents when used on their own. Traditional cancer therapy has relied on effective drug combinations and the more recent emergence of compounds that simultaneously modulate multiple targets has added to the oncology armoury and raised the question as to which approach, drug combinations or single compound multi-targeted drug, is to be preferred. This chapter reviews the basis for combining existing drugs and how these combinations are selected, and compares these with multi-targeted drugs (MTDs) such as sunitinib, a broad-spectrum kinase inhibitor that inhibits a range of growth factors. Whether using physical combinations or MTDs, or indeed combinations of MTDs, the choice of which targets and which pathways to attack is crucial and the rationale for selecting these is discussed in detail. The NCI Cancer Therapy Evaluation Program, designed to facilitate trials of novel combinations, will aid in the rational selection of targets and pathways to combine in future MTDs. The pros and cons of combinations and MTDs in terms of the relative challenges in clinical development are examined, and the systematic use of biomarkers, better approaches to patient selection, and improved design of trials to take account of the heightened potential for acute and delayed on- and off-target toxicities are highlighted.

Retinopathy Associated with Adjuvant High-Dose Interferon-α2b in a Patient with Resected Melanoma: A Case Report and Review of the Literature

Interferon is the only accepted adjuvant treatment for patients with melanoma; hence, oncologists should be aware of the possibility of retinal abnormalities resulting from its use. Interferon-associated retinopathy in patients being treated for resected melanoma is a rare phenomenon with a proposed immunological basis. Patients are usually asymptomatic or have mild visual impairments, with cotton wool infarcts and hemorrhages. These symptoms and signs usually resolve with the discontinuation of interferon, but in a few severe presentations the visual impairments and retinal changes can be irreversible.

Further Investigation of the Role of ACYP2 and WFS1 Pharmacogenomic Variants in the Development of Cisplatin-Induced Ototoxicity in Testicular Cancer Patients

Purpose: Adverse drug reactions such as ototoxicity, which occurs in approximately one-fifth of adult patients who receive cisplatin treatment, can incur large socioeconomic burdens on patients with testicular cancer who develop this cancer during early adulthood. Recent genome-wide association studies have identified genetic variants in ACYP2 and WFS1 that are associated with cisplatin-induced ototoxicity. We sought to explore the role of these genetic susceptibility factors to cisplatin-induced ototoxicity in patients with testicular cancer. Experimental Design: Extensive clinical and demographic data were collected for 229 patients with testicular cancer treated with cisplatin. Patients were genotyped for two variants, ACYP2 rs1872328 and WFS1 rs62283056, that have previously been associated with hearing loss in cisplatin-treated patients. Analyses were performed to investigate the association of these variants with ototoxicity in this cohort of adult patients with testicular cancer. Results: Pharmacogenomic analyses revealed that ACYP2 rs1872328 was significantly associated with cisplatin-induced ototoxicity [P = 2.83 × 10−3, OR (95% CI):14.7 (2.6–84.2)]. WFS1 rs62283056 was not significantly associated with ototoxicity caused by cisplatin (P = 0.39); however, this variant was associated with hearing loss attributable to any cause [P = 5.67 × 10−3, OR (95% CI): 3.2 (1.4–7.7)]. Conclusions: This study has provided the first evidence for the role of ACYP2 rs1872328 in cisplatin-induced ototoxicity in patients with testicular cancer. These results support the use of this information to guide the development of strategies to prevent cisplatin-induced ototoxicity across cancers. Further, this study has highlighted the importance of phenotypic differences in replication studies and has provided further evidence for the role of WFS1 rs62283056 in susceptibility to hearing loss, which may be worsened by cisplatin treatment. Clin Cancer Res; 24(8); 1866–71. ©2018 AACR.