Randomised phase II study of panitumumab plus irinotecan versus cetuximab plus irinotecan in patients with KRAS wild-type metastatic colorectal cancer refractory to fluoropyrimidine, irinotecan and oxaliplatin (WJOG 6510G)

The effective combination therapies with irinotecan for colorectal cancer

Colorectal cancer is the third most common type of cancer worldwide and has become one of the major human disease burdens. In clinical practice, the treatment of colorectal cancer has been closely related to the use of irinotecan. Irinotecan combines with many other anticancer drugs and has a broader range of drug combinations. Combination therapy is one of the most important means of improving anti-tumor efficacy and overcoming drug resistance. Reasonable combination therapy can lead to better patient treatment options, and inappropriate combination therapy will increase patient risk. For the colorectal therapeutic field, the significance of combination therapy is to improve the efficacy, reduce the adverse effects, and improve the ease of treatment. Therefore, we explored the clinical advantages of its combination therapy based on mechanism or metabolism and reviewed the rationale basis and its limitations in conducting exploratory clinical trials on irinotecan combination therapy, including the results of clinical trials on the combination potentiation of cytotoxic drugs, targeted agents, and herbal medicine. We hope that these can evoke more efforts to conduct irinotecan in the laboratory for further studies and evaluations, as well as the possibility of more in-depth development in future clinical trials.

Update on Targeted Therapy and Immunotherapy for Metastatic Colorectal Cancer

Metastatic colorectal cancer remains a deadly malignancy and is the third leading cause of cancer-related death. The mainstay of treatment for metastatic colorectal cancer is chemotherapy, but unfortunately, even with recent progress, overall survival is still poor. Colorectal cancer is a heterogeneous disease, and the underlying genetic differences among tumors can define the behavior and prognosis of the disease. Given the limitations of cytotoxic chemotherapy, research has focused on developing targeted therapy based on molecular subtyping. Since the early 2000s, multiple targeted therapies have demonstrated efficacy in treating metastatic colorectal cancer and have received FDA approval. The epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and DNA mismatch repair pathways have demonstrated promising results for targeted therapies. As new gene mutations and proteins involved in the oncogenesis of metastatic colorectal cancer are identified, new targets will continue to emerge. We herein provide a summary of the updated literature regarding targeted therapies for patients with mCRC.

Progress of research on molecular targeted therapies for colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies, accounting for approximately 10% of global cancer incidence and mortality. Approximately 20% of patients with CRC present metastatic disease (mCRC) at the time of diagnosis. Moreover, up to 50% of patients with localized disease eventually metastasize. mCRC encompasses a complex cascade of reactions involving multiple factors and processes, leading to a diverse array of molecular mechanisms. Improved comprehension of the pathways underlying cancer cell development and proliferation, coupled with the accessibility of relevant targeted agents, has propelled advancements in CRC treatment, ultimately leading to enhanced survival rates. Mutations in various pathways and location of the primary tumor in CRC influences the efficacy of targeted agents. This review summarizes available targeted agents for different CRC pathways, with a focus on recent advances in anti-angiogenic and anti-epidermal growth factor receptor agents, BRAF mutations, and human epidermal growth factor receptor 2-associated targeted agents.

A comparison of panitumumab and cetuximab in the treatment of KRAS wild-type metastatic colorectal cancer: a systematic review and meta-analysis

AIM

Cetuximab and panitumumab are common antibodies against epidermal growth factor receptor (EGFR) that can be used in combination with chemotherapy for the treatment of metastatic colorectal cancer (mCRC). Although these two drugs are considered to be very similar, differences in the efficacy and safety of cetuximab and panitumumab are still unclear. We conducted this meta-analysis to explore the effects and adverse reactions of cetuximab and panitumumab in the treatment of mCRC.

METHODS

We searched PubMed, the Cochrane Library, Embase, Web of Science, China national knowledge infrastructure (CNKI) and WanFang databases to identify records related to the efficacy and safety of cetuximab and panitumumab in the treatment of mCRC. The search terms were "cetuximab," "panitumumab," and "colorectal cancer." The deadline of searching was April 2022. Review manager 5.4 software was used to perform the statistical analysis for this meta-analysis. Pooled hazard ratio (HR) with 95% confidence intervals (CI) were calculated to evaluate the overall survival (OS) and progression free survival (PFS) of cetuximab and panitumumab in the treatment of mCRC.

RESULTS

There was no significant difference in OS, PFS, and response rate (RR) between cetuximab arm and panitumumab arm (OS: HR = 0.91, 95% CI = 0.81-1.03, p = .14; PFS: HR = 0.92, 95% CI = 0.83-1.02, p = .11; RR: OR = 1.22, 95% CI = 0.96-1.61, p = .14). We also did not observe any statistical difference between both arms in incidence of acneiform rash, severe acneiform rash, diarrhea, and severe diarrhea (acneiform rash: OR = 1.09, 95% CI = 0.84-1.42, p = .51; severe acneiform rash: OR = 1.50, 95% CI = 0.80-2.81, p = .21; diarrhea: OR = 1.08, 95% CI = 0.82-1.42, p = .58; severe diarrhea: OR = 0.90, 95% CI = 0.44-1.84, p = .77). The incidence of paronychia was decreased in the panitumumab arm, but that of hypomagnesemia and severe hypomagnesemia were decreased in the cetuximab arm. (paronychia: OR = 0.74, 95% CI = 0.55-1.00, p = .05; hypomagnesemia: OR = 1.85, 95% CI =1.41-2.41, p < .00001; severe hypomagnesemia: OR = 2.66, 95% CI = 1.52-4.67, p = .0006).

CONCLUSION

There was no significant difference in OS, PFS and RR between the cetuximab arm and panitumumab arm in the treatment of mCRC. For adverse reactions, the incidence of paronychia was decreased in the panitumumab arm, and the incidence of hypomagnesemia was deceased in the cetuximab arm.

Enhancing an Oxidative "Trojan Horse" Action of Vitamin C with Arsenic Trioxide for Effective Suppression of KRAS-Mutant Cancers: A Promising Path at the Bedside

The turn-on mutations of the KRAS gene, coding a small GTPase coupling growth factor signaling, are contributing to nearly 25% of all human cancers, leading to highly malignant tumors with poor outcomes. Targeting of oncogenic KRAS remains a most challenging task in oncology. Recently, the specific G12C mutant KRAS inhibitors have been developed but with a limited clinical outcome because they acquire drug resistance. Alternatively, exploiting a metabolic breach of KRAS-mutant cancer cells related to a glucose-dependent sensitivity to oxidative stress is becoming a promising indirect cancer targeting approach. Here, we discuss the use of a vitamin C (VC) acting in high dose as an oxidative "Trojan horse" agent for KRAS-mutant cancer cells that can be potentiated with another oxidizing drug arsenic trioxide (ATO) to obtain a potent and selective cytotoxic impact. Moreover, we outline the advantages of VC's non-natural enantiomer, D-VC, because of its distinctive pharmacokinetics and lower toxicity. Thus, the D-VC and ATO combination shows a promising path to treat KRAS-mutant cancers in clinical settings.

Safety Assessment on Serious Adverse Events of Targeted Therapeutic Agents Prescribed for RAS Wild-Type Metastatic Colorectal Cancer: Systematic Review and Network Meta-Analysis

Despite substantially elevated risk of serious adverse events (SAEs) from targeted therapy in combination with chemotherapy, comprehensive pharmacovigilance research is limited. This study aims to systematically assess SAE risks of commonly prescribed targeted agents (bevacizumab, cetuximab, and panitumumab) in patients with rat sarcoma viral oncogene homolog (RAS) wild-type metastatic colon cancer. Keyword searches of Cochrane Library, Clinical Key and MEDLINE were conducted per PRISMA-NMA guidelines. Frequentist network meta-analysis was performed with eight randomized controlled trials to compare relative risk (RR) of 21 SAE profiles. The risks of hematological, gastrointestinal, neurological SAE were insignificant among targeted agents (p > 0.05). The risk of serious hypertension was substantially elevated in bevacizumab-based chemotherapy (p < 0.05), whereas panitumumab-based chemotherapy had markedly elevated risk of serious thromboembolism (RR 3.65; 95% CI 1.30−10.26). Although both cetuximab and panitumumab demonstrated increased risk of serious dermatological and renal toxicities, panitumumab-based chemotherapy has relatively higher risk of skin toxicity (RR 15.22; 95% CI 7.17−32.35), mucositis (RR 3.18; 95% CI 1.52−6.65), hypomagnesemia (RR 20.10; 95% CI 5.92−68.21), and dehydration (RR 2.81; 95% CI 1.03−7.67) than cetuximab-based chemotherapy. Thus, further studies on risk stratification and SAE management are warranted for safe administration of targeted agents.

Efficacy and Safety of Systemic Treatments Among Colorectal Cancer Patients: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Systemic treatments, namely, either monotherapy or combination therapy, are commonly administered to patients with advanced or metastatic colorectal cancer (CRC). This study aimed to provide the complete efficacy and safety profiles and ranking of systemic therapies for the treatment of unresectable advanced or metastatic CRC.

METHODS

We searched PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov from inception until June 30, 2021, and also the bibliographies of relevant studies. Randomized controlled trials comparing two or more treatments, namely, at least capecitabine, 5-fluorouracil, leucovorin, irinotecan, bevacizumab, cetuximab, oxaliplatin, or panitumumab were investigated. A network meta-analysis using the Bayesian approach was performed to compare the efficacy and safety of treatments. The surface under the cumulative ranking curve (SUCRA) was calculated for the probability of each treatment as the most effective. The overall response rate (ORR), disease control rate (DCR), overall survival (OS), progression-free survival (PFS), adverse events (AEs) grade ≥3, and serious adverse events (SAEs) were evaluated.

RESULTS

One hundred two publications with 36,147 participants were assigned to 39 different treatments. Among 11 treatments with full information on six outcomes, FOLFIRI/FOLFOX/FOLFOXIRI + bevacizumab significantly improved both the ORR and DCR, compared to FOLFIRI. Although FOLFOX and FOLFIRI/FOLFOX + cetuximab significantly prolonged both OS and PFS, treatments were comparable in terms of AEs grade ≥3 and SAEs. The top highest SUCRA values were observed in the FOLFOXIRI + panitumumab group for ORR (96%) and DCR (99%), FOLFIRI + bevacizumab + panitumumab group for OS (62%) and PFS (54%), and FOLFOXIRI + bevacizumab group for AEs grade ≥3 (59%) and SAEs (59%) outcomes.

CONCLUSIONS

These findings suggest an available range of systemic treatment therapies with different efficacy and safety profiles with patients. Further investigations of the side effects and mutation status are required to confirm our findings.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42019127772.

Network Pharmacology Analysis to Explore the Pharmacological Mechanism of Effective Chinese Medicines in Treating Metastatic Colorectal Cancer using Meta-Analysis Approach

The role of traditional Chinese medicine (TCM) on treatment of metastatic colorectal cancer (mCRC) remains controversial, and its active components and potential targets are still unclear. This study mainly aimed to assess the efficacy and safety of TCM in mCRC treatment through meta-analysis and explore the effective components and potential targets based on the network pharmacology method. We systematically searched PubMed, EMBASE, Cochrane, CBM, WanFang, and CNKI database for randomized controlled trials (RCTs) comparing the treatment of mCRC patients with and without TCM. A meta-analysis using RevMan 5.4 was conducted. In total, 25 clinical trials were analyzed, and the result demonstrated that TCM was closely correlated with the improved OS (HR: 0.63; 95% CI: 0.52-0.76; [Formula: see text] < 0.00001) and PFS (HR: 0.73; 95% CI: 0.61-0.88; [Formula: see text] = 0.0010). Then, high-frequency Chinese herbs from the prescriptions extracted from the trails included in the OS meta-analysis were counted to construct a core-effective prescription. The TCMSP database was used to retrieve the active chemical components and predict herb targets. The Genecards, OMIM, Disgenet, DrugBank, and TTD database were searched for colorectal cancer targets. R-package was used to construct the Component-Target (C-T) network based on the intersection genes. Further, we extracted hub genes from C-T network and performed functional enrichment and pathway analysis. Finally, the C-T network showed 120 herb and disease co-target genes, and the most important top 10 active components were: Quercetin, Luteolin, Wogonin, Kaempferol, Nobiletin, Baicalein, Licochalcone A, Naringenin, Isorhamnetin, and Acacetin. The first 20 hub genes were extracted: CDKN1A, CDK1, CDK2, E2F1, CDK4, PCNA, RB1, CCNA2, MAPK3, CCND1, CCNB1, JUN, MAPK1, RELA, FOS, MAPK8, STAT3, MAPK14, NR3C1, and MYC. Thus, effective Chinese herb components may inhibit the mCRC by targeting multiple biological processes of the above hub genes.

Retreatment of Irinotecan in Later Lines of Therapy for Metastatic Colorectal Cancer: A Retrospective Study

BACKGROUND

Due to few efficacious options in later lines of therapy in metastatic colorectal cancer (mCRC), there has been considerable interest in the possibility of retreatment with previously administered agents. This study investigated the efficacy and safety of irinotecan retreatment (IRI2) in patients with refractory mCRC.

METHODS

We performed a retrospective analysis of patients with mCRC who were retreated with irinotecan-based regimens. The retreatment regimens with anti-epidermal growth factor receptor therapies were excluded.

RESULTS

A total of 64 patients were included. Patients had a median age of 56 years and were offered mainly in the setting of third- or fourth-line therapy with IRI2. The disease control rate was 78.2% including an objective response of 23.5%. Median progression-free survival and overall survival were 5.5 and 19.3 months, respectively. The most frequent grade 3 or higher toxicities were nausea/vomiting (27.9%) and neutropenia (25%).

CONCLUSION

IRI2 might be a reasonable option for heavily pretreated patients with mCRC who achieved disease control with prior irinotecan therapy.

Safety and efficacy of panitumumab in combination with trifluridine/tipiracil for pre-treated patients with unresectable, metastatic colorectal cancer with wild-type RAS: The phase 1/2 APOLLON study

Background

We aimed to assess the safety and efficacy of combination treatment with panitumumab plus trifluridine/tipiracil (FTD/TPI) in patients with wild-type RAS metastatic colorectal cancer (mCRC) who were refractory/intolerant to standard therapies other than anti-epidermal growth factor receptor therapy.

Methods

APOLLON was an open-label, multicentre, phase 1/2 trial. In the phase 1 part, 3 + 3 de-escalation design was used to investigate the recommended phase 2 dose (RP2D); all patients in the phase 2 part received the RP2D. The primary endpoint was investigator-assessed progression-free survival (PFS) rate at 6 months. Secondary endpoints included PFS, overall survival (OS), overall response rate (ORR), disease control rate (DCR), time to treatment failure (TTF), and safety.

Results

Fifty-six patients were enrolled (phase 1, n = 7; phase 2, n = 49) at 25 Japanese centres. No dose-limiting toxicities were observed in patients receiving panitumumab (6 mg/kg every 2 weeks) plus FTD/TPI (35 mg/m² twice daily; days 1–5 and 8–12 in a 28-day cycle), which became RP2D. PFS rate at 6 months was 33.3% (90% confidence interval [CI] 22.8–45.3). Median PFS, OS, ORR, DCR, and TTF were 5.8 months (95% CI 4.5–6.5), 14.1 months (95% CI 12.2–19.3), 37.0% (95% CI 24.3–51.3), 81.5% (95% CI 68.6–90.8), and 5.8 months (95% CI 4.29–6.21), respectively. Neutrophil count decreased (47.3%) was the most common Grade 3/4 treatment-emergent adverse event. No treatment-related deaths occurred.

Conclusion

Panitumumab plus FTD/TPI exhibited favourable anti-tumour activity with a manageable safety profile and may be a therapeutic option for pre-treated mCRC patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10147-021-01902-2.

Efficacy of Panitumumab and Cetuximab in Patients with Colorectal Cancer Previously Treated with Bevacizumab; a Combined Analysis of Individual Patient Data from ASPECCT and WJOG6510G

Background: Phase-III ASPECCT and randomised phase-II WJOG6510G trials demonstrated the noninferiority of panitumumab, when compared with cetuximab, for overall survival in patients with chemotherapy-refractory wild-type KRAS exon 2 metastatic colorectal cancer. Methods: The subgroup that received bevacizumab either prior to panitumumab or cetuximab monotherapy (ASPECCT) or in combination with irinotecan (WJOG6510G) was included. Multivariate Cox models were created, including the treatment arms as covariates together with patient, disease and treatment characteristics. Results: We included 185 and 189 patients in the panitumumab and cetuximab arms, respectively. The median overall survival was 12.8 and 10.1 months [p = 0.0031; log-rank test, stratified by trial; hazard ratio (HR), 0.72; 95% confidence interval (CI), 0.58–0.90], and the median progression-free survival was 4.7 and 4.1 months, in the panitumumab and cetuximab arms, respectively (p = 0.0207; HR, 0.79; 95% CI, 0.64–0.97). The treatment regimen was an independent prognostic factor of overall survival (adjusted HR, 0.69; 95% CI, 0.54–0.87; p = 0.0013). Conclusions: Panitumumab significantly prolonged the overall survival and progression-free survival, when compared with cetuximab in the cohort that previously received bevacizumab in the included studies. Clinical Trial Registration: ASPECCT trial registered with ClinicalTrials.gov (NCT01001377) and WJOG6510G trial registered with UMIN-CTR (UMIN000006643).