Case Report: Should Regorafenib be prescribed as a continuous schedule in gastrointestinal stromal tumors? Three case reports on Regorafenib personalized schedule

Introduction

Regorafenib is a tyrosine kinase inhibitor (TKI) approved in metastatic gastrointestinal stromal tumor (GIST), colorectal cancer, and hepatocarcinoma. Anyway, the toxicity profile of Regorafenib standard schedule is associated with poor compliance and a high rate of discontinuation. For this reason, there is a growing need for a Regorafenib personalized schedule emerging from the scientific community.

Objective

The aim of this case series was to describe the experience of our sarcoma referral center with the continuous administration of Regorafenib as an alternative regimen to treat metastatic GIST patients.

Methods

We retrospectively collected clinical, pathological, and radiological data of patients with metastatic GIST treated with daily personalized Regorafenib at a single tertiary referral center from May 2021 to December 2022.

Results

We identified three patients fulfilling the inclusion criteria. The average follow-up since the start of Regorafenib was 19.1 months (12-25 months). All three patients had started a standard third-line Regorafenib schedule according to guidelines. The reasons for switching to a continuous schedule were as follows: exacerbation of symptoms during week-off treatment in the first patient, a serious adverse event (AE) in the second patient, and a combination of both conditions in the third. After switching, none of the patients reported severe AEs, and they improved control of tumor-related symptoms. Two of the patients experienced disease progression after 16 months (9 months of which is continuous schedule) and 12 months (8.1 months of which is continuous schedule) of Regorafenib, respectively; the third patient is still receiving continuous Regorafenib at the time of writing, with a progression-free survival of 25 months (14 months after the modified schedule start).

Conclusion

With a similar efficacy and lower toxicities, a daily, personalized Regorafenib schedule seems to be a promising alternative to the standard regimen for metastatic GIST patients, including the frail ones. Further prospective analyses are needed to confirm the safety and efficacy of such regimen.

Regorafenib outcomes from the population based South Australian Metastatic Colorectal Cancer Registry

AIM

Reviewing outcomes of regorafenib use in metastatic colorectal cancer using real-world data from the South Australian Metastatic Colorectal Cancer Registry.

METHODS

A retrospective review of the characteristics and outcomes of patients who received regorafenib in the Registry up to December 2018. The registry started in February 2006.

RESULTS

Fifty-three patients received regorafenib therapy since approved by the therapeutic goods administration in November 2013. The median age was 66 (range 34-82). 66% were male, 66% had stage IV disease at diagnosis, 53% had liver only involvement, whereas 13% had liver and lung disease and 6% had lung only involvement. 75% had left-sided primary. KRAS was available in 35/53 patients with 49% of them being WT. BRAF status was known in 8/53 with 25% of them having a mutated variant. MSI testing was known in 14 patients in whom 21% of them had MSI-High tumors. Prior lines of treatment received: one line 4%, two 9%, three 23%, four 26%, >four 37%. Prior biological use: bevacizumab 72%, anti-EGFR 100% (for RAS WT). Median survival from diagnosis was 3.3 years (95% CI, 2.8-3.8 years). Median survival from the start of regorafenib was 7.1 months (95% CI, 4.8-9.4 months) and the 12-month survival rate was 28%.

CONCLUSION

The survival outcome for those patients from our population-based registry who access regorafenib is in keeping with reports from large, randomized trials. Thus, clinicians can quote local real world data when discussing efficacy and access to regorafenib therapy for mCRC patients.

Regorafenib and ginsenoside combination therapy: inhibition of HepG2 cell growth through modulating survivin and caspase-3 gene expression

BACKGROUND

This work aimed to investigate the inhibitory effect of regorafenib in combination with ginsenoside on the growth of HepG2 liver cancer cells.

METHODS

HepG2 liver cancer cells were divided into blank control group, regorafenib single-drug group, ginsenoside single-drug group, and regorafenib/ginsenoside combination group. Cells in the regorafenib single-drug group were treated with regorafenib at 0.25 mg/L, 0.5 mg/L, and 1 mg/L, respectively, while cells in the ginsenoside single-drug group were treated with ginsenoside at 5.0 mg/L, 10.0 mg/L, and 20.0 mg/L, respectively. HepG2 cell proliferation, expression of survivin mRNA, and the apoptotic effector caspase-3 in HepG2 liver cancer cells were assessed.

RESULTS

An inhibitory effect on the growth of HepG2 liver cancer cells was observed for both the single-drug therapies and the combination therapy. The synergistic inhibitory effect presented by the combination therapy was dependent on the gradient concentration and treatment time. RT-qPCR results showed that both regorafenib and ginsenoside significantly reduced the expression of survivin mRNA in HepG2 liver cancer cells and the expression level of survivin mRNA in the regorafenib/ginsenoside combination group was much lower than those in the regorafenib single-drug group and ginsenoside single-drug group. The two drugs demonstrated synergistic inhibitory effect when used in combination.

CONCLUSIONS

The findings in this study offered a theoretical insight into clinical use of regorafenib and ginsenoside for treatment of liver cancer.

A phase 1b study evaluating the safety and pharmacokinetics of regorafenib in combination with cetuximab in patients with advanced solid tumors

Regorafenib 160 mg orally once daily (QD) 3 weeks on/1 week off is approved in colorectal cancer, gastrointestinal stromal tumors and hepatocellular carcinoma. We established the safety and pharmacokinetics (PK) of regorafenib combined with cetuximab in advanced refractory solid tumors. This was a phase 1, open-label, dose-escalation study (NCT01973868) in patients with advanced/metastatic solid tumors who progressed after standard therapy. Regorafenib was administered at various dose levels QD continuously or intermittently (3 weeks on/1 week off) combined with intravenous cetuximab 250 mg/m² weekly. The primary objectives were safety, PK and maximum tolerated dose (MTD). The secondary objective was tumor response. Dose-limiting toxicities (DLTs) were evaluated in Cycle 1. Of 42 treated patients, 31 received regorafenib intermittently (120 mg, n = 8; 160 mg, n = 23) and 11 continuously (60 mg, n = 5; 100 mg, n = 6) plus cetuximab. The continuous arm was terminated due to low tolerable dose. In the intermittent arm, one DLT (grade 3 hand-foot skin reaction) was observed at 120 mg but none at 160 mg, therefore 160 mg/day was declared as the MTD in combination with cetuximab. The most common all-grade treatment-emergent adverse events were fatigue (52%), hypophosphatemia (48%) and diarrhea (40%). One grade 3 cetuximab-related dermatitis acneiform was observed. No clinically relevant drug-drug interactions were observed. Five patients (21%) had a partial response. Regorafenib 160 mg QD (3 weeks on/1 week off) plus standard dose of cetuximab was well tolerated with no unexpected toxicities and promising signs of efficacy.

Phase II Trial of Continuous Regorafenib Dosing in Patients with Gastrointestinal Stromal Tumors After Failure of Imatinib and Sunitinib

BACKGROUND

Regorafenib at the standard intermittent dosing schedule proved effective in the GRID trial for refractory gastrointestinal stromal tumors (GISTs). However, this dosing schedule requires frequent dose reduction, and the progression of GISTs or tumor-related symptoms during the off-treatment period has also been noted in some patients. Therefore, we conducted this phase II trial to evaluate the efficacy and safety of regorafenib at a lower dose on a continuous dosing schedule.

METHODS

Patients with measurable, metastatic, or recurrent GISTs who failed to respond to both imatinib and sunitinib were eligible for this study. Regorafenib 100 mg p.o. daily was administered continuously. The primary endpoint was disease control rate (DCR: complete response plus partial response [PR] plus stable disease [SD]) lasting for at least 12 weeks using RECIST version 1.1.

RESULTS

The best response was PR in 2 (8%), SD in 16 (64%), and progressive disease in 6 (24%) patients. DCR lasting for at least 12 weeks was 64% (16 of 25). The median progression-free survival was 7.3 months (95% confidence interval, 5.9-8.6), and the 1-year survival rate was 64.5%. Ten patients (40%) experienced grade 3-4 toxicities, including hand-foot skin reaction (n = 4, 16%) and elevation of alanine aminotransferase (n = 2, 8%). Only six patients (24%) needed dose modification with a relative dose intensity of 95.0% for eight cycles in all patients.

CONCLUSION

Regorafenib at a lower dose on a continuous schedule might be an alternative treatment in patients with GISTs after failure of imatinib and sunitinib. Clinical trial identification number. NCT02889328 IMPLICATIONS FOR PRACTICE: Regorafenib at the standard intermittent dosing schedule proved effective in the GRID trial for refractory gastrointestinal stromal tumors (GISTs). However, this dosing schedule requires frequent dose reduction, and the progression of GISTs or tumor-related symptoms during the off-treatment period has been noted in some patients. This study was to evaluate the efficacy and safety of regorafenib at a lower dose on a continuous dosing schedule. With good efficacy and acceptable safety profiles, regorafenib at a lower, continuously administered dose might be an alternative treatment in patients with GISTs after imatinib and sunitinib. Rechallenge of regorafenib may slow the disease progression.

Regorafenib as treatment for patients with advanced hepatocellular cancer

Hepatocellular carcinoma is one of the fastest growing causes of cancer-related mortality worldwide. Sorafenib was the first and only drug to improve survival for patients with advanced disease, and has been the cornerstone of treatment for nearly a decade. Regorafenib is a multikinase inhibitor that has recently been shown to significantly improve survival in patients who have progressed on first-line sorafenib. In this review, we discuss the pharmacokinetic and pharmacodynamics properties of regorafenib and its efficacy and tolerability in patients with advanced hepatocellular carcinoma.

Efficacy and Safety of Regorafenib in Korean Patients with Advanced Gastrointestinal Stromal Tumor after Failure of Imatinib and Sunitinib: A Multicenter Study Based on the Management Access Program

PURPOSE

The aim of this study was to confirm the efficacy and safety of regorafenib for advanced gastrointestinal stromal tumors (GISTs) reported in the GRID phase III trial in Korean patients.

MATERIALS AND METHODS

Fifty-seven Korean patientswith advanced GISTwho experienced both imatinib and sunitinib failure were enrolled in the management access program between December 2012 and November 2013 and treated with regorafenib (160 mg orally once daily in a 3 weeks on/1 week off).

RESULTS

None of the patients achieved a complete or partial response while 25 patients (44%) showed stable disease for ≥ 12 weeks. With a median follow-up of 12.7 months (range, 0.2 to 27.6 months), the median progression-free survival and overall survival were 4.5 months (95% confidence interval [CI], 3.8 to 5.3) and 12.9 months (95% CI, 8.1 to 17.7), respectively. Interestingly, 15 patients (26%) experienced an exacerbation of their cancer-related symptoms (abdominal pain in eight and abdominal distension in five) during the rest period for regorafenib, but all were ameliorated upon the resumption of regorafenib. The most common grade 3 or 4 adverse event was a hand-foot skin reaction (25%). The regorafenib dose was reduced in 44 patients (77%) due to toxicity, which manifested mainly as a hand-foot skin reaction (n=31).

CONCLUSION

This study confirmed the efficacy and safety of regorafenib for advanced GIST after imatinib and sunitinib failure in Korean patients. Considering the exacerbation of the cancer-related symptoms observed during the rest periods, further exploration of the continuous dosing schedule of regorafenib is warranted in future clinical trials.

Management of regorafenib-related toxicities: a review

Regorafenib (Stivarga, BAY 73-4506; Bayer Pharma AG, Berlin, Germany) is an oral multikinase inhibitor that targets the angiogenic tumor microenvironment and oncogenic kinases including vascular endothelial growth factor receptor 2 (VEGFR2), VEGFR1, VEGFR3, fibroblast growth factor receptor 1 (FGFR1), RAF, KIT, RET and BRAF. Its antiangiogenic effect is greater than that of its related drug, sorafenib. Regorafenib has been approved by the US Food and Drug Administration (FDA) for the treatment of metastatic colorectal cancer (mCRC) in patients who have failed treatment with fluoropyrimidine, oxaliplatin and irinotecan based chemotherapy, an anti-VEGF therapy and, if KRAS wild type, an anti-EGFR therapy. The FDA based this approval on data from the CORRECT trial, which showed the efficacy of regorafenib compared with placebo. The most common grade 3-4 adverse reactions with the drug are hand foot skin reactions (HFSR), diarrhea, hypertension and fatigue. This review discusses the efficacy data, and the incidence and management of regorafenib's toxicities.

Regorafenib as a new standard of care in advanced colorectal cancer

SUMMARY 

Standard treatment for metastatic colorectal cancer (mCRC) involves chemotherapy based on fluoropyrimidines, oxaliplatin, irinotecan and treatments targeting the angiogenic pathway, and EGFR in RAS wild-type tumors. Regorafenib, an active multikinase inhibitor, demonstrated activity against mCRC in Phase I and II studies. The CORRECT study demonstrated activity of regorafenib in third line versus placebo. The primary end point (overall survival), was met (6.4 vs 5.0 months [hazard ratio: 0.77; 95% CI: 0.64–0.94; p = 0.0052]). Median progression-free survival was 1.9 versus 1.7 months (hazard ratio: 0.49; 95% CI: 0.42–0.58; p < 0.0001). Most common adverse events of regorafenib were hand–foot skin reaction, fatigue, diarrhea, hypertension and rash or desquamation and stomatitis, but with a close management and/or dose modifications were controlled. In conclusion, regorafenib is a new standard in third line in mCRC.

Regorafenib as a single-agent in the treatment of patients with gastrointestinal tumors: an overview for pharmacists

Regorafenib (BAY 73-4506, Stivarga® Bayer HealthCare Pharmaceutical Inc) is an oral multikinase inhibitor with a distinct and wide-ranging profile of tyrosine kinase inhibition, resulting in antiangiogenic and antiproliferative properties in tumors. Single-agent regorafenib administered as a 160-mg daily dose for the first 21 days of a 28-day cycle is approved for use in patients with pretreated metastatic colorectal cancer (mCRC) and gastrointestinal stromal tumor (GIST) progressing on imatinib and sunitinib, following publication of data from the phase III CORRECT and GRID studies respectively. Regorafenib is currently under phase III investigation in patients with hepatocellular carcinoma and is in several phase II studies in patients with gastrointestinal (GI) tumors. This review describes the clinical development of regorafenib in patients with GI cancers, and highlights the key issues important for the modern day clinical pharmacist who forms part of the multidisciplinary team ensuring safe and effective delivery of the drug to the patient. This information is considered of particular importance to the clinical pharmacist for the future development of regorafenib in this treatment setting.

Regorafenib for gastrointestinal malignancies : from preclinical data to clinical results of a novel multi-target inhibitor

Intracellular signals for cancer cell growth, proliferation, migration, and survival are frequently triggered by protein tyrosine kinases (TKs). The possibility of disrupting core disease pathways has led to development and widespread clinical use of specific TK inhibitors that in the past decade have markedly changed treatment strategies and impacted on overall outcomes. However, intrinsic resistance may limit the benefit of these drugs, and multiple escape routes compensate for the inhibited signaling. The disruption of several points of the same pathway and the simultaneous interference with different intracellular oncogenic processes have both been recognized as valuable strategies to maximize the therapeutic potential of this class of agents. In this scenario, regorafenib has emerged as a novel, orally active, multitarget compound with potent activity against a number of angiogenic and stromal TKs, including vascular endothelial growth factor receptor 2 (VEGFR-2), tyrosine kinase with immunoglobulin-like and EGF-like domains 2 (TIE-2), fibroblast growth factor receptor 1 (FGFR-1), and platelet-derived growth factor receptor (PDGFR). Moreover, the drug has the capability of blocking KIT, RET and V600 mutant BRAF. Starting from interesting preclinical results, this review describes the clinical development of regorafenib in gastrointestinal malignancies, focusing on data derived from cutting edge clinical trials that have provided evidence of efficacy in pretreated patients with advanced colorectal cancer or gastrointestinal stromal tumors.

Evolving approaches to patients with advanced differentiated thyroid cancer

Advanced differentiated thyroid cancer (DTC), defined by clinical characteristics including gross extrathyroidal invasion, distant metastases, radioiodine (RAI) resistance, and avidity for 18-fluorodeoxyglucose (positron emission tomography-positive), is found in approximately 10-20% of patients with DTC. Standard therapy (surgery, RAI, TSH suppression with levothyroxine) is ineffective for many of these patients, as is standard chemotherapy. Our understanding of the molecular mechanisms leading to DTC and the transformation to advanced DTC has rapidly evolved over the past 15-20 years. Newer targeted therapy, specifically inhibitors of intracellular kinase signaling pathways, and cooperative multicenter clinical trials have dramatically changed the therapeutic landscape for patients with advanced DTC. In this review focusing on morbidities, molecules, and medicinals, we present a patient with advanced DTC, explore the genetics and molecular biology of advanced DTC, and review evolving therapies for these patients including multikinase inhibitors, selective kinase inhibitors, and combination therapies.