A phase I open-label trial evaluating the cardiovascular safety of regorafenib in patients with advanced cancer

Recent Perspectives on Cardiovascular Toxicity Associated with Colorectal Cancer Drug Therapy

Cardiotoxicity is a well-known adverse effect of cancer-related therapy that has a significant influence on patient outcomes and quality of life. The use of antineoplastic drugs to treat colorectal cancers (CRCs) is associated with a number of undesirable side effects including cardiac complications. For both sexes, CRC ranks second and accounts for four out of every ten cancer deaths. According to the reports, almost 39% of patients with colorectal cancer who underwent first-line chemotherapy suffered cardiovascular impairment. Although 5-fluorouracil is still the backbone of chemotherapy regimen for colorectal, gastric, and breast cancers, cardiotoxicity caused by 5-fluorouracil might affect anywhere from 1.5% to 18% of patients. The precise mechanisms underlying cardiotoxicity associated with CRC treatment are complex and may involve the modulation of various signaling pathways crucial for maintaining cardiac health including TKI ErbB2 or NRG-1, VEGF, PDGF, BRAF/Ras/Raf/MEK/ERK, and the PI3/ERK/AMPK/mTOR pathway, resulting in oxidative stress, mitochondrial dysfunction, inflammation, and apoptosis, ultimately damaging cardiac tissue. Thus, the identification and management of cardiotoxicity associated with CRC drug therapy while minimizing the negative impact have become increasingly important. The purpose of this review is to catalog the potential cardiotoxicities caused by anticancer drugs and targeted therapy used to treat colorectal cancer as well as strategies focused on early diagnosing, prevention, and treatment of cardiotoxicity associated with anticancer drugs used in CRC therapy.

Clinical Pharmacokinetics and Pharmacodynamics of Transarterial Chemoembolization and Targeted Therapies in Hepatocellular Carcinoma

The management of hepatocellular carcinoma (HCC) is based on a multidisciplinary decision tree. Treatment includes loco-regional therapy, mainly transarterial chemoembolization, for intermediate-stage HCC and systemic therapy with oral tyrosine kinase inhibitors (TKIs) for advanced HCC. Transarterial chemoembolization involves hepatic intra-arterial infusion with either conventional procedure or drug-eluting-beads. The aim of the loco-regional procedure is to deliver treatment as close as possible to the tumor both to embolize the tumor area and to enhance efficacy and minimize systemic toxicity of the anticancer drug. Pharmacokinetic studies applied to transarterial chemoembolization are rare and pharmacodynamic studies even rarer. However, all available studies lead to the same conclusions: use of the transarterial route lowers systemic exposure to the cytotoxic drug and leads to much higher tumor drug concentrations than does a similar dose via the intravenous route. However, reproducibility of the procedure remains a major problem, and no consensus exists regarding the choice of anticancer drug and its dosage. Systemic therapy with TKIs is based on sorafenib and lenvatinib as first-line treatment and regorafenib and cabozantinib as second-line treatment. Clinical use of TKIs is challenging because of their complex pharmacokinetics, with high liver metabolism yielding both active metabolites and their common toxicities. Changes in liver function over time with the progression of HCC adds further complexity to the use of TKIs. The challenges posed by TKIs and the HCC disease process means monitoring of TKIs is required to improve clinical management. To date, only partial data supporting sorafenib monitoring is available. Results from further pharmacokinetic/pharmacodynamic studies of these four TKIs are eagerly awaited and are expected to permit such monitoring and the development of consensus guidelines.

Regorafenib: A Review in Metastatic Colorectal Cancer

Regorafenib (Stivarga^®) is an oral small-molecule multiple kinase inhibitor. It is indicated worldwide for patients with metastatic colorectal cancer (mCRC). In the EU and USA it is indicated for patients with mCRC who have been previously treated with, or are not considered candidates for available therapies, including fluoropyrimidine-based chemotherapy, an anti-VEGF therapy and, if RAS wild-type, an anti-EGFR therapy. In Japan, it is indicated for the treatment of unresectable, advanced/recurrent CRC. The addition of regorafenib to best supportive care prolonged median overall survival (OS; by up to 2.5 months) and progression-free survival (PFS; by up to 1.5 months) relative to the addition of placebo in double-blind phase 3 studies (CORRECT and CONCUR) in patients with mCRC who had progressed after failure of standard therapy. Health-related quality of life was not adversely affected with regorafenib relative to placebo. A large open-label phase 3 study (CONSIGN) and several large real-world studies supported the efficacy of regorafenib in this setting. Regorafenib had a generally manageable tolerability profile, which was consistent with the profile of a typical small-molecule multiple kinase inhibitor. Treatment-related adverse events (AEs), mostly of mild or moderate severity, were reported in the majority of patients receiving regorafenib, with dermatological toxicities and liver enzyme elevations among the most common AEs. Although identification of biomarkers/parameters predicting efficacy outcomes with regorafenib will help to individualize therapy, current evidence indicates that regorafenib is a valuable treatment option for patients with refractory mCRC who have a very poor prognosis.

Regorafenib: A Review in Hepatocellular Carcinoma

Regorafenib (Stivarga^®), a small molecule inhibitor of multiple kinases, is the first drug to be approved for the treatment of hepatocellular carcinoma (HCC) in patients who have progressed during or after sorafenib therapy. Its approval was based on the results of the randomized, double-blind, placebo-controlled, multinational, phase III RESORCE trial in patients with HCC who had progressed during sorafenib therapy. In RESORCE, regorafenib significantly prolonged overall survival (OS; primary endpoint), progression-free survival (PFS) and time to progression (TTP) compared with placebo, with the OS benefit appearing to be largely due to disease stabilization. Regorafenib had an acceptable tolerability profile. The most common treatment-related adverse events in the regorafenib group included hand-foot skin reaction, fatigue, diarrhoea and hypertension. No fatal hepatic failure was reported with regorafenib in patients with HCC in RESORCE. In conclusion, current evidence suggests that regorafenib is an important new targeted therapy option for the treatment of HCC patients who have progressed on sorafenib therapy.

Adverse events risk associated with regorafenib in the treatment of advanced solid tumors: meta-analysis of randomized controlled trials

Background

Regorafenib is a novel multikinase inhibitor (MKI) approved for use in the treatment of metastatic colorectal cancer (CRC), treatment-refractory gastrointestinal stromal tumors, and other solid tumor malignancies. However, the adverse events (AEs) associated with regorafenib have not been systematically investigated. Hence, we performed a meta-analysis to identify AEs associated with regorafenib in patients with advanced solid tumors.

Methods

The databases of PubMed, MEDLINE, and Embase and abstracts presented in American Society of Clinical Oncology annual meetings were searched for relevant publications from January 2004 to September 2017. Eligible studies were limited to prospective randomized controlled trials (RCTs) that evaluate the use of regorafenib in patients with advanced solid tumors. Incidence, relative risk (RR), and 95% CIs were calculated using a random or fixed effects model on the basis of the heterogeneity of the included studies.

Results

A total of 2,065 patients from six RCTs were included, and 1,340 of them received regorafenib and 725 received a placebo. Sixteen all-grade AEs and 15 high-grade AEs were investigated for their association with regorafenib. Results showed that hand-foot skin reaction (HFSR; 54%), diarrhea (33%), fatigue (32%), hypertension (31%), oral mucositis (28%), and anorexia (23%) were the most frequent clinical AEs. The most common high-grade (grade, ≥3) AEs were HFSR (16%), hypertension (13%), fatigue (6%), increased aspartate aminotransferase (AST; 6%), and hypophosphatemia (6%). Pooled RR showed that the use of regorafenib was associated with an increased risk of developing AEs. Subgroup analysis based on the prior MKI treatment showed that prior MKI treatment was associated with an increased incidence of all-grade anorexia (P=0.03) and a reduced incidence of high-grade increased AST (P=0.04). However, subgroup analysis based on the tumor type showed that no significant differences were found when comparing the RR of all-grade and high-grade AEs in patients with CRC or non-CRC.

Conclusion

The meta-analysis systematically investigated regorafenib-associated AEs. Knowledge of these AEs is essential for minimizing treatment-related toxicities and improving clinical outcomes.

Antiangiogenic tyrosine kinase inhibitors in colorectal cancer: is there a path to making them more effective?

Antiangiogenic therapy has a proven survival benefit in metastatic colorectal cancer. Inhibition of the VEGF pathway using a variety of extracellular antibody approaches has clear benefit in combination with chemotherapy, while intracellular blockade using tyrosine kinase inhibitors (TKIs) such as sorafenib and regorafenib has had more limited success. Pharmacodynamic modeling using modalities such as DCE-MRI indicates potent antiangiogenic effects of these TKIs, yet numerous combination therapies, primarily with chemotherapy, have failed to demonstrate an additive benefit. The sole comparative study of a single agent TKI against placebo showed a survival benefit of regorafenib in patients with advanced, refractory disease. Preclinical data demonstrate synergy between antiantiogenic TKIs and targeted interventions including autophagy inhibition, and together with a renewed effort to define markers of susceptibility, such combinations may be a way to improve the limited efficacy of this once-promising drug class.

Targeting gastrointestinal stromal tumors: the role of regorafenib

Gastrointestinal stromal tumor (GIST) is a devastating disease in the metastatic setting, but its natural history has been dramatically altered by the development of small molecule tyrosine kinase inhibitors, most notably imatinib. Although patients with advanced GIST live much longer today than they did in the past, imatinib-refractory disease remains a tremendous problem. For disease that is refractory to imatinib and sunitinib, regorafenib is an excellent option. In this review, we discuss the biology and clinical work establishing regorafenib as the standard of care for advanced GIST refractory to both imatinib and sunitinib.