Comparative Safety of Targeted Therapies for Metastatic Colorectal Cancer between Elderly and Younger Patients: a Study Using the International Pharmacovigilance Database

Opportunities and challenges of pharmacovigilance in special populations: a narrative review of the literature

The relatively new discipline of pharmacovigilance (PV) aims to monitor the safety of drugs throughout their evolution and is essential to discovering new drug risks. Due to their specific and complex physiology, children, pregnant women, and elderly adults are more prone to adverse drug reactions (ADRs). Additionally, the lack of clinical trial data exacerbates the challenges faced with pharmacotherapy in these populations. Elderly patients tend to have multiple comorbidities often requiring more extensive medication, which adds additional challenges for healthcare professionals (HCPs) in delivering safe and effective pharmacotherapy. Clinical trials often have inherent limitations, including insufficient sample size and limited duration of research; as some ADRs are attributed to long-term use of a drug, these may go undetected during the course of the trial. Therefore, the implementation of PV is key to insuring the safe and effective use of drugs in special populations. We conducted a thorough review of the scientific literature on PV systems across the European Union, the United States, and China. Our review focused on basic physiological characteristics, drug use, and PV for specific populations (children, pregnant women, and the elderly). This article aims to provide a reference for the development of follow-up policies and improvement of existing policies as well as provide insight into drug safety with respect to patients of special populations.

Uncovering Knowledge Gaps in the Safety Profile of Antiangiogenic Drugs in Cancer Patients: Insights from Spontaneous Reporting Systems Studies

Global repositories of postmarketing safety reports improve understanding of real-life drug toxicities, often not observed in clinical trials. The aim of this scoping review was to map the evidence from spontaneous reporting systems studies (SRSs) of antiangiogenic drugs (AADs) in cancer patients and highlight if the found disproportionality signals of adverse events (AEs) were validated and thus mentioned in the respective Summary of product Characteristics (SmPC). This scoping review was conducted according to PRISMA guidelines for scoping reviews. A knowledge gap on the safety of AADs was found: firstly, several cardiovascular AEs were not mentioned in the SmPCs and no pharmacovigilance studies were conducted despite the well-known safety concerns about these drugs on the cardiovascular system. Second, a disproportionality signal (not validated through causality assessment) of pericardial disease was found in the literature for axitinib with no mention in SmPC of the drug. Despite the exclusion of pharmacoepidemiological studies, we believe that this scoping review, which focuses on an entire class of drugs, could be considered as a novel approach to highlight possible safety concerns of drugs and as a guide for the conduction of a target postmarketing surveillance on AADs.

Safety and efficacy review of aflibercept for the treatment of metastatic colorectal cancer

INTRODUCTION

Anti-angiogenic drugs are an efficacious class of therapy in the treatment of patients with metastatic colorectal cancer (mCRC). Aflibercept, a vascular endothelial growth factor (VEGF) trap which binds the angiogenic factors VEGF-A, VEGF-B, and placental growth factor (PIGF) is approved in combination with FOLFIRI chemotherapy following progression after an oxaliplatin-containing regimen.

AREAS COVERED

This report provides a review of the practice-changing clinical studies which have established the use of anti-angiogenic therapy as second-line therapy in mCRC including aflibercept with FOLFIRI (5FU, leucovorin, irinotecan). This review also evaluates aflibercept with other chemotherapy regimens as well as efficacy and safety data from real-world studies.

EXPERT OPINION

Aflibercept in combination with FOLFIRI chemotherapy is an established safe and efficacious regimen for the treatment of mCRC as second-line chemotherapy. Although several toxicities have been described, the majority are either low grade or manageable by drug cessation and supportive therapies. For optimal outcomes, patient selection and close observation of toxicities is essential.

Anti-PD-1 and regorafenib induce severe multisystem adverse events in microsatellite stability metastatic colorectal cancer: a case report

There exists a dilemma in the treatment of microsatellite stability (MSS) metastatic colorectal cancer (mCRC) owing to limited therapeutic options. Based on the promising results of the REGONIVO trial, combination of anti-PD-1 and regorafenib could be applicable for this kind of patients. Here we first report a case of an MSS mCRC patient who received sinitilimab plus regorafenib as third-line treatment and suffered severe multisystem treatment-related adverse events including Grade 3 myocarditis, myositis, myasthenia gravis, dermatitis, hepatitis, etc. Fortunately, all these adverse events have been reversed with administration of corticosteroids. Though evidence of tumor shrinkage was not found, CEA levels markedly decreased. Therefore, anti-PD-1 plus regorafenib might be optional for the MSS mCRC patients which requires special caution in the clinical practice.

Effect of Synchronous Versus Sequential Regimens on the Pharmacokinetics and Biodistribution of Regorafenib with Irradiation

This study was performed to evaluate the interaction between conventional or high-dose radiotherapy (RT) and the pharmacokinetics (PK) of regorafenib in concurrent or sequential regimens for the treatment of hepatocellular carcinoma. Concurrent and sequential in vitro and in vivo studies of irradiation and regorafenib were designed. The interactions of RT and regorafenib in vitro were examined in the human hepatoma Huh-7, HA22T and Hep G2 cell lines. The RT–PK phenomenon and biodistribution of regorafenib under RT were confirmed in a free-moving rat model. Regorafenib inhibited the viability of Huh-7 cells in a dose-dependent manner. Apoptosis in Huh-7 cells was enhanced by RT followed by regorafenib treatment. In the concurrent regimen, RT decreased the area under the concentration versus time curve (AUC)_regorafenib by 74% (p = 0.001) in the RT_{2 Gy × 3 fraction (f’x)} group and by 69% (p = 0.001) in the RT_{9 Gy × 3 f’x} group. The AUC_regorafenib was increased by 182.8% (p = 0.011) in the sequential RT_{2Gy × 1 f’x} group and by 213.2% (p = 0.016) in the sequential RT_{9Gy × 1 f’x} group. Both concurrent regimens, RT_{2Gy × 3 f’x} and RT_{9Gy × 3 f’x}, clearly decreased the biodistribution of regorafenib in the heart, liver, lung, spleen and kidneys, compared to the control (regorafenib _{× 3 d}) group. The concurrent regimens, both RT_{2Gy × 3 f’x} and RT_{9Gy × 3 f’x}, significantly decreased the biodistribution of regorafenib, compared with the control group. The PK of regorafenib can be modulated both by off-target irradiation and stereotactic body radiation therapy (SBRT).

Lessons to be Learnt from Real-World Studies on Immune-Related Adverse Events with Checkpoint Inhibitors: A Clinical Perspective from Pharmacovigilance

The advent of immune checkpoint inhibitors (ICIs) caused a paradigm shift both in drug development and clinical practice; however, by virtue of their mechanism of action, the excessively activated immune system results in a multitude of off-target toxicities, the so-called immune-related adverse events (irAEs), requiring new skills for timely diagnosis and a multidisciplinary approach to successfully manage the patients. In the recent past, a plethora of large-scale pharmacovigilance analyses have characterized various irAEs in terms of spectrum and clinical features in the real world. This review aims to summarize and critically appraise the current landscape of pharmacovigilance studies, thus deriving take-home messages for oncologists. A brief primer to study design, conduction, and data interpretation is also offered. As of February 2020, 30 real-world postmarketing studies have characterized multiple irAEs through international spontaneous reporting systems, namely WHO Vigibase and the US FDA Adverse Event Reporting System. The majority of studies investigated a single irAE and provided new epidemiological evidence about class-specific patterns of irAEs (i.e. anti-cytotoxic T-lymphocyte antigen 4 [CTLA-4] versus anti-programmed cell death 1 [PD-1] receptor, and its ligand [PD-L1]), kinetics of appearance, co-occurrences (overlap) among irAEs, and fatality rate. Oncologists should be aware of both strengths and limitations of these pharmacovigilance analyses, especially in terms of data interpretation. Optimal management (including rechallenge), predictivity of irAEs (as potential biomarkers of effectiveness), and comparative safety of ICIs (also in terms of combination regimens) represent key research priorities for next-generation real-world studies.

Treatment guidelines of metastatic colorectal cancer in older patients from the French Society of Geriatric Oncology (SoFOG)

BACKGROUND

Several guidelines dedicated to metastatic colorectal cancer (mCRC) are available. Since 2013 no recent guidelines are specifically dedicated to older patients and based on a systematic review.

MATERIALS AND METHODS

A multidisciplinary Task Force with digestive oncologists, geriatricians and methodologists from the SoFOG was formed in 2016 to update recommendations on medical treatment of mCRC based on a systematic review of publications from 2000 to 2018. Search strategy has followed a standardized protocol from the formulation of clinical questions and definition of a search algorithm to the selection of complete articles for recommendations.

RESULTS

The four selected key questions were: For which older patients with mCRC can we considered: (1) Any chemotherapy, (2) Mono or poly-chemotherapy, (3) Anti-angiogenic therapy, (4) Other targeted therapy. Main recommendations for older patients are: (1) Omission of chemotherapy should be discussed with a geriatrician for patients with severe comorbidities, advanced dementia, uncontrolled psychiatric disorder or severe loss of autonomy. (2) If tumor response is not the main aim, a mono-chemotherapy with 5-fluorouracil combined with bevacizumab is recommended as first-line. (3) For patients with symptoms related to metastases or with a planned metastasis ablation, a doublet chemotherapy combined with bevacizumab or anti-EGFR antibody in the context of a RAS wild type tumor is recommended as first-line. Preliminary data suggest that regorafenib may be used, in its registered indication, in patients under 80 with a performance status of 0 and no autonomy alterations and that trifluridine-tipiracil may be used with a tight supervising of hematological function.

Safety and Effectiveness of Aflibercept + Fluorouracil, Leucovorin, and Irinotecan (FOLFIRI) for the Treatment of Patients with Metastatic Colorectal Cancer (mCRC) in Current Clinical Practice: OZONE Study

For patients with metastatic colorectal cancer (mCRC) that have failed a first-line oxaliplatin-based regimen, the preferred treatment option is an irinotecan-based regimen. This prospective, observational, noncomparative, post-authorization safety study (OZONE) evaluated the safety and effectiveness of aflibercept plus fluorouracil, leucovorin, and irinotecan (FOLFIRI) in patients with mCRC treated in daily practice after failure of an oxaliplatin-based regimen. Patients were grouped by age, renal impairment, hepatic impairment, race, number, and type of prior anticancer therapy. Of 766 treated patients enrolled, 59.5% were male, 94.8% had an Eastern Cooperative Oncology Group performance status of 0–1, all received previous chemotherapy (97.8% including oxaliplatin), and 58.6% had prior exposure to bevacizumab. At least one grade ≥ 3 treatment-emergent adverse event (TEAE) was reported in 68.3% of patients. Neutropenia, hypertension, diarrhea, and asthenia were the most frequently occurring grade ≥ 3 TEAEs. Antivascular endothelial growth factor class events were infrequent. Subgroup analyses did not reveal major differences in the safety profile according to age, renal and hepatic status, race, or prior anticancer therapy. For the total population, median overall survival was 12.5 months, median progression-free survival was 6.1 months, and overall response rate was 16.3%. Aflibercept in combination with FOLFIRI is a safe and efficacious regimen administered in current clinical practice to patients with mCRC previously treated with oxaliplatin. The study results, conducted in real-world clinical practice with a less selected patient population, are aligned with the VELOUR (NCT00561470) trial and no new safety issues were identified.

Toxicities with Immune Checkpoint Inhibitors: Emerging Priorities From Disproportionality Analysis of the FDA Adverse Event Reporting System

BACKGROUND

Immune checkpoint inhibitors (ICIs), including antibodies targeting cytotoxic T-lymphocyte associated protein 4 (CTLA4) and programmed cell death 1 or its ligand (PD1/PDL1), elicit different immune-related adverse events (irAEs), but their global safety is incompletely characterized.

OBJECTIVE

The aim of this study was to characterize the spectrum, frequency, and clinical features of ICI-related adverse events (AEs) reported to the FDA Adverse Event Reporting System (FAERS).

PATIENTS AND METHODS

AEs from FAERS (up to June 2018) recording ICIs (ipilimumab, nivolumab, pembrolizumab, atezolizumab, avelumab, durvalumab) as suspect were extracted. Comprehensive disproportionality analyses were performed through the reporting odds ratio (ROR) with 95% confidence interval (95% CI), using other oncological drugs as comparison. An overview of systematic reviews (OoSRs) was also undertaken to identify irAEs with consistent positive associations.

RESULTS

ICIs were recorded in 47,266 reports, submitted mainly by consumers receiving monotherapy with anti-PD1/PDL1 drugs. Three areas of toxicity emerged from both disproportionality analysis and the OoSRs (32 studies): endocrine (N = 2863; ROR = 6.91; 95% CI 6.60-7.23), hepatobiliary (2632; 1.33; 1.28-1.39), and respiratory disorders (7240; 1.04; 1.01-1.06). Different reporting patterns emerged for anti-CTLA4 drugs (e.g., hypophysitis, adrenal insufficiency, hypopituitarism, and prescribed overdose) and anti-PD1/PDL1 agents (e.g., pneumonitis, cholangitis, vanishing bile duct syndrome, tumor pseudoprogression, and inappropriate schedule of drug administration). No increased reporting emerged when comparing combination with monotherapy regimens, but multiple hepatobiliary/endocrine/respiratory irAEs were recorded.

CONCLUSIONS

This parallel approach through contemporary post-marketing analysis and OoSRs confirmed that ICIs are associated with a multitude of irAEs, with different reporting patterns between anti-CTLA4 and anti-PD1/PDL1 medications. Close clinical monitoring is warranted to early diagnose and timely manage irAEs, especially respiratory, endocrine, and hepatic toxicities, which warrant further characterization; patient- and drug-related risk factors should be assessed through analytical pharmaco-epidemiological studies and prospective multicenter registries.

First-line single-agent regorafenib in frail patients with metastatic colorectal cancer: a pilot phase II study of the Spanish Cooperative Group for the Treatment of Digestive Tumours (TTD)

BACKGROUND

Treatment of frail patients with advanced colorectal cancer (CRC) is controversial. This pilot phase II trial aimed to assess the efficacy and safety of regorafenib when administered in first-line to frail patients with advanced CRC.

METHODS

Frail patients without prior advanced colorectal cancer treatment were included in the study. Definition of frailty was defined per protocol based on dependency criteria, presence of chronic comorbid pathologies and/or geriatric features.

MAIN OBJECTIVE

to assess progression-free survival (PFS) rate at 6 months. Treatment consisted of 28-day cycles of orally administered regorafenib 160 mg/day (3 weeks followed by 1 week rest).

RESULTS

Forty-seven patients were included in the study. Median age was 81 years (range 63-89). Frailty criteria: dependency was observed in 26 patients (55%), comorbidities in 27 (57%) and geriatric features in 18 (38%). PFS rate at 6 months was 45% (95% confidence interval [CI] 30-60]. Median PFS was 5.6 months (95%CI 2.7-8.4). Median overall survival (OS) was 16 months (95%CI 7.8-24). Complete response, partial response and stable disease were observed in one, two and 21 patients respectively (objective response rate 6.4%; disease control rate 51%). Thirty-nine patients (83%) experienced grade 3-4 adverse events (AEs). The most common grade 3-4 AEs were hypertension (15 patients; 32%), asthenia (14; 30%), hypophosphatemia (6; 13%); diarrhea (4; 8%), hand-foot-skin reaction (4; 8%). There were two toxic deaths (4.2%) (grade 5 rectal bleeding and death not further specified). Dose reduction was required in 26 patients (55%) and dose-delays in 13 patients (28%).

CONCLUSIONS

The study did not meet the pre-specified boundary of 55% PFS rate at 6 months. Toxicity observed (83% patients experienced grade 3 and 4 AEs) preclude its current use in clinical practice on this setting. Disease control rate and overall survival results are interesting and might warrant further investigation to identify those who benefit from this approach.

TRIAL REGISTRATION

This trial was prospectively registered at EudraCT ( 2013-000236-94 ). Date of trial registration: April 9th, 2013.

Treatment Modalities and Survival in Older Adults with Metastatic Colorectal Cancer in Real Life

OBJECTIVES

Metastatic colorectal cancer (mCRC) is increasingly treated with targeted therapies, but little is known about real-life mCRC treatment in older adults. The aims were to describe the real-life first-line treatment modalities in older adult mCRC patients, to identify factors associated with treatment modalities, and to evaluate survival with regard to treatment modalities.

PATIENTS AND METHODS

A cohort of mCRC patients aged 65 years and older at diagnosis was identified between 2009 and 2013 using French national healthcare insurance system claims data. Treatment modalities were: treatment with one or more anticancer medication vs best supportive care and, among treated patients, treatment with targeted therapy vs conventional chemotherapy alone. Multivariate logistic regression was used to identify factors associated with treatment by anticancer medication and by targeted therapy. Cox proportional hazards models were used to assess the independent effect of treatment modalities on overall survival while adjusting for baseline covariates identified with logistic regression.

RESULTS

A total of 503 patients were included with a median age of 78 years (54% were men). Of these, 299 (59%) were treated with anticancer medications. Among treated patients, 131 (44%) received targeted therapy. In multivariate analysis, age 75 years or older, renal failure, malnutrition, and five or more concomitant medications were associated with a lower likelihood of treatment with anticancer medications. Among treated patients, age 75 years or older, history of cancer, lymph node metastases, and a single metastatic site were associated with a lower likelihood of treatment with targeted therapy. Multivariate Cox proportional hazards models found that treatment with any anticancer medication tended to be associated with a lower risk of death; treatment with targeted therapy was not significantly associated.

CONCLUSION

A more appropriate prescription of anticancer medications in the older adult will require the definition of more explicit criteria to avoid undertreatment. The real benefit of targeted therapies vs conventional chemotherapy alone needs to be confirmed in this population. J Am Geriatr Soc 67:913-919, 2019.

Patterns of Use, Safety, and Effectiveness of Targeted Therapies in First-Line Treatment of Metastatic Colorectal Cancer According to Age: The STROMBOLI Cohort Study

BACKGROUND

Metastatic colorectal cancer (mCRC) is increasingly treated using targeted therapies. Their real-life evaluation is insufficient, especially in elderly and frail patients. The aim was to describe use, safety, and effectiveness of targeted therapies in first-line mCRC treatment according to age.

PATIENTS AND METHODS

Two field cohorts of patients initiating bevacizumab or cetuximab for first-line mCRC were pooled. Patients characteristics, use, and safety were compared between younger and elderly patients (<75 vs. ≥75 years). Two-year overall survival (OS) and progression-free survival (PFS) were estimated in both age groups using the Kaplan-Meier method adjusted on factors associated with death or progression identified with Cox multivariate modeling.

RESULTS

Eight hundred patients (n = 411, 51.4% bevacizumab) were included: 498 (62.3%) male, median age 64 years, 118 (14.8%) Eastern Cooperative Oncology Group performance status (ECOG-PS) ≥2. Elderly patients (n = 126, 15.8%) were more often treated with 5-fluorouracil alone than younger. Severe adverse events were equivalent across age groups. ECOG-PS ≥1, abnormal hemoglobin, and abnormal alkaline phosphatases were associated with a higher risk of death; OS adjusted on these factors was similar between elderly and younger patients. ECOG-PS ≥1, lung metastases, abnormal hemoglobin, and abnormal creatinine clearance were associated with a higher risk of progression or death; PFS adjusted on these factors was similar across groups.

CONCLUSION

Despite treatment adaptations, elderly patients could benefit from targeted therapies as younger without safety warning.

Efficacy and Safety of Regorafenib With 2/1 Schedule for Patients ≥ 75 Years With Metastatic Colorectal Cancer (mCRC) After Failure of 2 Lines of Chemotherapy

BACKGROUND

In the CORRECT (patients with metastatic COloRectal Cancer treated with REgorafenib or plaCebo after failure of standard Therapy) trial, regorafenib was proven to extend survival of patients with metastatic colorectal cancer (mCRC) that progressed after all available therapies. Grade 3 to 4 toxicity occurred in 54% of patients, and data on the activity and tolerability of regorafenib in elderly patients were scarce. The aim of this study was to evaluate the efficacy and safety of an alternative schedule, 2-week-on treatment and 1 week-off (2/1 schedule), of regorafenib for elderly patients with mCRC.

PATIENTS AND METHODS

Patients ≥ 75 years with mCRC who progressed after oxaliplatin- and irinotecan-based chemotherapy received regorafenib on a 2/1 schedule. Potentially frail subjects were identified by G8 screening tool and excluded. The 2-month disease-control rate was the primary endpoint, and the secondary endpoints included safety, progression-free survival (PFS), overall survival (OS), and objective response rate.

RESULTS

Between February 2014 and May 2017, 23 patients with mCRC were recruited at our institution. No partial or complete responses were observed, and the stable disease and disease-control rate were 52.2%. The median PFS was 4.8 months (95% confidence interval, 3.8-6.3 months), and the median OS was 8.9 months (95% confidence interval, 6.9-10.6 months). Adverse events were uncommon, and the most frequent grade 3 toxicity adverse events were hand-foot skin reaction (9%) and fatigue (9%). Toxicity-related dose reductions and discontinuations occurred in 5 and 2 patients, respectively.

CONCLUSION

Regorafenib administered with a modified 2/1 schedule to patients who were aged ≥ 75 years and non-frail with treatment-refractory mCRC seems to be tolerable and achieve encouraging results in terms of PFS and OS.