Panitumumab Plus Fluorouracil and Folinic Acid Versus Fluorouracil and Folinic Acid Alone as Maintenance Therapy in RAS Wild-Type Metastatic Colorectal Cancer: The Randomized PANAMA Trial (AIO KRK 0212)

Discontinuation of immune checkpoint inhibitors in hepatocellular carcinoma: a retrospective cohort study

Background

The optimal timing to discontinue immune checkpoint inhibitor (ICI) therapy in hepatocellular carcinoma (HCC) patients with clinical benefits remains unclear. This study aimed to assess the outcomes of HCC patients after ICI discontinuation.

Methods

Patients with HCC were retrospectively screened and those discontinued ICI therapy in the absence of progressive disease (PD) were included. Responses at discontinuation were evaluated per response evaluation criteria in solid tumors (RECIST) version 1.1 and modified RECIST (mRECIST). Patients were classified into five subgroups according to the cause of discontinuation: complete response (CR), partial response (PR), stable disease (SD) per RESICT version 1.1, adverse event (AE), or others. Progression-free survival (PFS) and overall survival (OS) since ICI start or after ICI discontinuation were assessed.

Results

A total of 66 patients were included. The median follow-up was 29.33 months. The median PFS since ICI start was 30.83 months [95% confidence interval (CI): 24.93-36.72], and the median OS was not reached. The median PFS after discontinuation was 20.6 months (95% CI: 7.63-33.56), and the median OS after discontinuation was not reached. Univariate analysis showed that age, treatment after discontinuation, Response (RECIST version 1.1) at discontinuation and modified response (mResponse per mRECIST) at discontinuation were significantly associated with PFS after discontinuation, while age and mResponse at discontinuation were significantly associated with OS after discontinuation. Multivariate analysis further demonstrated that mResponse at discontinuation and treatment after discontinuation were independently associated with PFS after discontinuation, while age was independently associated with OS after discontinuation.

Conclusions

ICIs might be discontinued in HCC patients with a response of CR per mRECIST. Patients with a response of PR/SD per mRECIST or elder age could continue ICI therapy after achieving clinical benefits. Tyrosine kinase inhibitor (TKI) maintenance therapy might help to prevent progression after ICI discontinuation.

Superior Outcomes of Dual-Arterial Coronary Artery Bypass Grafting Are Maintained in the Veterans Health Administration

INTRODUCTION

Controversy surrounds the long-term clinical benefit of coronary artery bypass grafting (CABG) using dual arterial grafts (DAGs) compared to single arterial grafts (SAGs). We investigated outcomes of DAG, using single internal thoracic artery and radial artery (DAG-RA) or bilateral internal thoracic artery grafts (DAG-BITA), compared to SAG, using the left internal thoracic artery and saphenous vein grafts, in the U.S. Veterans Health Administration (VA).

METHODS

We conducted a cross-sectional study of U.S. Veterans undergoing isolated on-pump CABG between 2005 and 2015 at 44 VA medical centers. The primary composite outcome was first occurrence of a major adverse cardiac and cerebrovascular event (MACCE), comprised of death from any cause, myocardial infarction, stroke, or repeat revascularization.

RESULTS

Among 25,969 Veterans undergoing isolated CABG, 1261 (4.9%) underwent DAG (66.8% DAG-RA and 33.2% DAG-BITA). Over a 5-y follow-up, DAG was associated with lower rates of all-cause death (adjusted hazard ratio [AHR] 0.70, 95% confidence interval [CI] 0.58-0.85), MACCE (AHR 0.80, 95% CI 0.71-0.91), and stroke (AHR 0.74, 95% CI 0.57-0.96) versus SAG. DAG-BITA was associated with lower rates of all-cause death (AHR 0.52, 95% CI 0.35-0.77) and MACCE (AHR 0.66, 95% CI 0.51-0.84) than SAG, while DAG-RA was associated with lower rates of all-cause death (AHR 0.79, 95% CI 0.64-0.99).

CONCLUSIONS

In the VA, DAG was associated with improved long-term MACCE outcomes compared to SAG. These results suggest that the practice of DAG in the VA benefits Veterans and should be promoted further.

Dermatology-related quality-of-life outcomes in patients with RAS wild-type metastatic colorectal cancer treated with fluorouracil and folinic acid with or without panitumumab (Pmab) maintenance after FOLFOX + Pmab induction: a prespecified secondary analysis of the phase II randomized PanaMa (AIO KRK 0212) trial

BACKGROUND

The key endpoints for the assessment of the effect of maintenance therapy for metastatic colorectal cancer (mCRC) are survival and quality-of-life outcomes. We aimed to compare dermatology-related quality of life (DRQOL) in patients with RAS wild-type (wt) mCRC treated with fluorouracil and folinic acid (FU/FA) + panitumumab (Pmab) versus FU/FA alone as maintenance therapy after folinic acid, fluorouracil and oxaliplatin + Pmab induction.

PATIENTS AND METHODS

The phase II randomized PanaMa (AIO KRK 0212; NCT01991873) trial included 387 patients at 70 community/academic sites in Germany. For this prespecified secondary analysis, DRQOL outcomes were assessed using the Functional Assessment of Cancer Therapy-epidermal growth factor receptor inhibitor (FACT-EGFRI), Dermatology Life Quality Index (DLQI), and Skindex-16 questionnaires at every second cycle of therapy until disease progression/death.

RESULTS

At least one DRQOL questionnaire was completed by a total of 310/377 (82%) patients who received induction therapy, and by 216/248 (87%) patients who were randomized and received maintenance therapy. Patients who experienced skin toxicity according to the National Cancer Institute (NCI)-Common Terminology Criteria for Adverse Events (CTCAE) during induction therapy had significantly worse DRQOL according to all three measures, compared to those who did not [i.e. Skindex-16, mean difference at cycle 2 -12.87; 95% confidence interval (CI) -20.01 to -5.73; P < 0.001]. During maintenance therapy, significantly improved recovery was observed in all DRQOL measures for patients receiving FU/FA, compared to those receiving additional Pmab (i.e. Skindex-16, mean difference at cycle 6 -16.53; 95% CI -22.68 to -10.38; P < 0.001).

CONCLUSIONS

In this secondary analysis of a phase II randomized clinical trial, patient-reported DRQOL outcomes correlated with skin toxicity according to NCI-CTCAE during induction therapy. Maintenance therapy with FU/FA + Pmab was associated with deteriorated DRQOL versus FU/FA alone in patients with RAS wt mCRC.

Therapeutic strategies targeting the epidermal growth factor receptor signaling pathway in metastatic colorectal cancer

More than 1.9 million new colorectal cancer (CRC) cases and 935000 deaths were estimated to occur worldwide in 2020, representing about one in ten cancer cases and deaths. Overall, colorectal ranks third in incidence, but second in mortality. More than half of the patients are in advanced stages at diagnosis. Treatment options are complex because of the heterogeneity of the patient population, including different molecular subtypes. Treatments have included conventional fluorouracil-based chemotherapy, targeted therapy, immunotherapy, etc. In recent years, with the development of genetic testing technology, more and more targeted drugs have been applied to the treatment of CRC, which has further prolonged the survival of metastatic CRC patients.

Navigating through novelties concerning mCRC treatment-the role of immunotherapy, chemotherapy, and targeted therapy in mCRC

Over the course of nearly six decades since the inception of initial trials involving 5-FU in the treatment of mCRC (metastatic colorectal cancer), our progressive comprehension of the pathophysiology, genetics, and surgical techniques related to mCRC has paved the way for the introduction of novel therapeutic modalities. These advancements not only have augmented the overall survival but have also positively impacted the quality of life (QoL) for affected individuals. Despite the remarkable progress made in the last two decades in the development of chemotherapy, immunotherapy, and target therapies, mCRC remains an incurable disease, with a 5-year survival rate of 14%. In this comprehensive review, our primary goal is to present an overview of mCRC treatment methods following the latest guidelines provided by the National Comprehensive Cancer Network (NCCN), the American Society of Clinical Oncology (ASCO), and the American Society of Colon and Rectal Surgeons (ASCRS). Emphasis has been placed on outlining treatment approaches encompassing chemotherapy, immunotherapy, targeted therapy, and surgery's role in managing mCRC. Furthermore, our review delves into prospective avenues for developing new therapies, offering a glimpse into the future of alternative pathways that hold potential for advancing the field.

Fluorouracil, Leucovorin, and Irinotecan Plus Cetuximab Versus Cetuximab as Maintenance Therapy in First-Line Therapy for RAS and BRAF Wild-Type Metastatic Colorectal Cancer: Phase III ERMES Study

PURPOSE

The intensity of anti-EGFR-based first-line therapy for RAS/BRAF wild-type (wt) metastatic colorectal cancer (mCRC), once disease control is achieved, is controversial. A de-escalation strategy with anti-EGFR monotherapy represents a potential option to maintain efficacy while reducing cytotoxicity.

METHODS

In this multicenter, open-label, phase III trial, patients with untreated RAS/BRAF wt mCRC were randomly assigned to receive either fluorouracil, leucovorin, and irinotecan/cetuximab (FOLFIRI/Cet) until disease progression (arm A) or FOLFIRI/Cet for eight cycles followed by Cet alone (arm B). The coprimary end points were a noninferior progression-free survival (PFS) in the modified per-protocol (mPP) population (>eight cycles) and a lower incidence of grade (G) 3-4 adverse events (AEs) for arm B compared with arm A.

RESULTS

Overall, 606 patients were randomly assigned, with 300 assigned to arm A and 306 to arm B. The median follow-up was 22.3 months. In the mPP population, 291 events occurred with a PFS of 10 versus 12.2 months for arms B and A, respectively (P of noninferiority = .43). In the intention-to-treatment (ITT, ≥one cycle) population, 503 events occurred with a PFS of 9 versus 10.7 months (P = .39). The overall survival was 35.7 versus 30.7 months (P = .119) and 31.0 versus 25.2 months (P = .32) in the mPP and ITT population, respectively. Arm B had lower G3-4 AEs during the maintenance period than arm A (20.2% v 35.1%).

CONCLUSION

The ERMES study did not demonstrate noninferiority of maintenance with Cet alone. Despite a more favorable safety profile, maintenance with single-agent Cet after induction with FOLFIRI/Cet cannot be recommended for all patients but could represent an option in selected cases.

Current advances in targeted therapy for metastatic colorectal cancer - Clinical translation and future directions

The last two decades have witnessed major breakthroughs in the development of targeted therapy for patients with metastatic colorectal cancer (mCRC), an achievement which stems largely from advances in translational research. Precision medicine is now widely practiced in routine oncological care, where systemic therapy is individualized based on clinical factors such as primary tumor sidedness, location and number of metastases, as well as molecular factors such as the RAS and BRAF mutation status, mismatch repair / microsatellite status and presence of other actionable genomic alterations in the tumor. The optimal selection of patients with RAS and BRAF-wild type (WT), left-sided primary tumor for treatment with epidermal growth factor receptor (EGFR) and chemotherapy (chemo) has markedly improved survival in the first-line setting. The pivotal trials of cetuximab in combination with BRAF/ MEK inhibitor for BRAF V600E mutant mCRC, and panitumumab with KRAS G12C inhibitor in KRAS(G12C)-mutant mCRC have been practice-changing. Anti-HER2 small molecular inhibitor, antibodies and antibody-drug conjugates have significantly improved the treatment outcome of patients with HER2 amplified mCRC. Anti-angiogenesis agents are now used across all lines of treatment and novel combinations with immune-checkpoint inhibitors are under active investigation in MSS mCRC. The non-invasive monitoring of molecular resistance to targeted therapies using Next Generation Sequencing analysis of circulating tumor-derived DNA (ctDNA) and captured sequencing of tumors have improved patient selection for targeted therapies. This review will focus on how latest advances, challenges and future directions in the development of targeted therapies in mCRC.

Negative Hyperselection of Resistance Mutations for Panitumumab Maintenance in RAS Wild-Type Metastatic Colorectal Cancer (PanaMa Phase II Trial, AIO KRK 0212)

PURPOSE

We evaluated additional mutations in RAS wild-type (WT) metastatic colorectal cancer (mCRC) as prognostic and predictive biomarkers for the efficacy of added panitumumab to a 5-fluorouracil plus folinic acid (FU/FA) maintenance as pre-specified analysis of the randomized PanaMa trial.

PATIENTS AND METHODS

Mutations (MUT) were identified using targeted next-generation sequencing (NGS; Illumina Cancer Hotspot Panel v2) and IHC. RAS/BRAF V600E/PIK3CA/AKT1/ALK1/ERBB2/PTEN MUT and HER2/neu overexpressions were negatively hyperselected and correlated with median progression-free survival (PFS) and overall survival (OS) since start of maintenance treatment, and objective response rates (ORR). Univariate/multivariate Cox regression estimated hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

202 of 248 patients (81.5%) of the full analysis set (FAS) had available NGS data: hyperselection WT, 162 (80.2%); MUT, 40 (19.8%). From start of maintenance therapy, hyperselection WT tumors were associated with longer median PFS as compared with hyperselection MUT mCRC (7.5 vs. 5.4 months; HR, 0.75; 95% CI, 0.52-1.07; P = 0.11), OS (28.7 vs. 22.2 months; HR, 0.53; 95% CI, 0.36-0.77; P = 0.001), and higher ORR (35.8% vs. 25.0%, P = 0.26). The addition of panitumumab to maintenance was associated with significant benefit in hyperselection WT tumors for PFS (9.2 vs. 6.0 months; HR, 0.66; 95% CI, 0.47-0.93; P = 0.02) and numerically also for OS (36.9 vs. 24.9 months; HR, 0.91; 95% CI, 0.61-1.36; P = 0.50), but not in hyperselection MUT tumors. Hyperselection status interacted with maintenance treatment arms in terms of PFS (P = 0.06) and OS (P = 0.009).

CONCLUSIONS

Extended molecular profiling beyond RAS may have the potential to improve the patient selection for anti-EGFR containing maintenance regimens.

Prognostic and predictive impact of metastatic organ involvement on maintenance therapy in advanced metastatic colorectal cancer: Subgroup analysis of patients treated within the PanaMa trial (AIO KRK 0212)

Despite molecular selection, patients (pts) with RAS wildtype mCRC represent a heterogeneous population including diversity in metastatic spread. We investigated metastatic patterns for their prognostic and predictive impact on maintenance therapy with 5-fluorouracil/folinic acid ± panitumumab. The study population was stratified according to (1) number of involved metastatic sites (single vs multiple organ metastasis), liver-limited disease vs (2) liver metastasis plus one additional site, and (3) vs liver metastasis plus ≥two additional sites. Kaplan-Meier method and Cox regressions were used to correlate efficacy endpoints. Single organ metastasis was observed in 133 pts (53.6%) with 102 pts (41.1%) presenting with liver-limited disease, while multiple organ metastases were reported in 114 pts (46.0). Multiple compared to single organ metastases were associated with less favorable PFS (HR 1.48, 95% CI 1.13-1.93; P = .004) and OS (HR 1.37, 95% CI 0.98-1.93; P = .068) of maintenance therapy. While metastatic spread involving one additional extrahepatic site was not associated with clearly impaired survival compared to liver-limited disease, pts with liver metastasis plus ≥two additional sites demonstrated less favorable PFS (HR 1.92, 95% CI 1.30-2.83; P < .001), and OS (HR 2.38, 95% CI 1.51-3.76; P < .001) of maintenance therapy. Pmab-containing maintenance therapy appeared active in both pts with multiple (HR 0.58; 95% CI, 0.39-0.86; P = .006) as well as to a lesser numerical extent in pts with single organ metastasis (HR 0.83; 95% CI, 0.57-1.21; P = .332; Interaction P = .183). These data may support clinical decisions when EGFR-based maintenance therapy is considered.

Efficacy of different maintenance strategies for RAS wild-type colorectal cancer: A network meta-analysis

INTRODUCTION

In metastatic RAS wild-type colorectal cancer (CRC), induction combination chemotherapy doublets (CT) with an anti-EGFR agent are considered the primary treatment. We performed a network meta-analysis (NMA) to compare the relative efficacy of different maintenance treatments for advanced RAS wild-type CRC.

MATERIALS AND METHODS

PubMed, EMBASE and Cochrane, from database inception until December 2021 were used. Randomized clinical trials enrolling adults with advanced RAS wild-type CRC and providing overall survival (OS) and/or progression-free survival (PFS) data PRISMA guidelines for NMA were followed. Between-group comparisons were estimated using hazard ratios (HRs) with 95% credible intervals (95% CrIs). Agents were ranked using surface under the cumulative ranking (SUCRA) probabilities.

RESULTS

A total of 7 randomized phase 2 trials were included (for a total of 1286 patients). Compared to depotentiation treatments, continuous CT + anti-EGFR was not significantly superior to other maintenance regimens for OS and was ranked as the best option for NMA (SUCRA p-score=0.69). Conversely, in the PFS analysis, single-agent fluoropyrimidines + anti-EGFR was ranked as the best treatment (SUCRA p-score=0.60).

CONCLUSIONS

Maintaining chemotherapy doublet + anti-EGFR until progression appears to be the best first-line strategy in terms of OS for advanced unresectable RAS wild-type mCRC treatment. However, fluoropyrimidines single-agent + cetuximab or panitumumab represent a reasonable choice regarding PFS.

The FJQR Has Synergistic Effect with Fluoropyrimidine in the Maintenance Treatment for HER-2 Negative Gastric Cancer

INTRODUCTION

Maintenance therapy aimed to strengthen the first-line chemotherapy and improve quality of life is needed for gastric cancer (GC). Currently, many clinical studies have confirmed the important role of fluoropyrimidine in the maintenance stage. Our team has created patented prescriptions "Fuzheng jiedu Quyu Method" recipe (FJQR), which was considered as an adjuvant therapeutic scheme (reduce toxicity and increase the efficacy of chemotherapy). This study aimed to evaluate the efficacy and safety of FJQR combined with fluoropyrimidine as a maintenance treatment in HER-2 negative GC patients.

METHODS

We performed the analysis of 129 patients with HER-2 negative GC who entered the maintenance stage in our hospital and Tianjin Cancer Hospital between January 2018 and December 2020. Out of the 129 eligible patients, 64 were categorized into the maintenance treatment group with FJQR+fluoropyrimidine, and 65 patients were assigned to the control group if they received fluoropyrimidine alone. Capecitabine was orally 1000mg/m2, Qd, half an hour after meals, and FGQR was 15g Bid after capecitabine. The primary endpoint was progression-free survival (PFS). The secondary endpoints were overall survival (OS), overall remission rate (ORR), quality of Life (QOL), TCM syndrome and safety.

RESULTS

The mPFS in the treatment group was significantly prolonged compared with the control group (6.3 vs. 5.0 months, p = 0.03), while the mOS was not substantially improved (11.4 vs. 10.5 months, p = 0.38). Gastrointestinal symptoms and pain became better in the treatment group. The number of distant metastatic organs, first-line chemotherapy cycles, and lymph node metastasis were independent risk predictors for PFS. Blood stasis syndrome may be the protective factor. In terms of safety, treatment-related adverse events (AEs) in the treatment group were relatively lighter, and the incidence of grade III-IV AEs could be significantly reduced.

CONCLUSION

FJQR and fluoropyrimidine have synergistic effects as maintenance treatment in HER-2 negative GC, with good efficacy and safety.

Anti-epidermal growth factor receptor targeted therapy-associated ulcerations

The well-studied role of epidermal growth factor receptor (EGFR) in metastatic colorectal cancer (mCRC) and non-small cell lung cancer (NSCLC) has enabled the development of drugs that target this molecule, including panitumumab for the former and osimertinib for the latter. Oral adverse events due to those agents are rarely described in the literature and their exact characterization is hampered by inadequate reporting and/or incorrect terminology used. We report two cases of panitumumab- and osimertinib-associated oral ulcerations with emphasis on their possible pathogenesis and optimal management.

Potential Efficacy of Shiunko for Anti-Epidermal Growth Factor Receptor (EGFR) Monoclonal Antibody-Induced Skin Fissure: A Single Institutional Case Series

PURPOSE

Anti-epidermal growth factor receptor monoclonal antibody (anti-EGFR mAb) is the key drug for RAS/BRAF V600E wild-type metastatic colorectal cancer (mCRC). However, anti-EGFR mAb-induced skin fissures often affect a patient's quality of life. Shiunko, a traditional Japanese topical herbal medicine, is used for burns and dermatitis and may potentially have wound-healing effects. Herein, we report cases of patients with mCRC who were treated with Shiunko for anti-EGFR mAb-induced skin fissure.

METHODS

We retrospectively reviewed consecutive patients with mCRC who received an anti-EGFR mAb-containing regimen and were treated with Shiunko twice a day for skin fissures at the National Cancer Center Hospital East between March 2022 and December 2022. Skin fissures were assessed at baseline and at every visit until 28 days after Shiunko initiation according to CTCAE v5.0.

RESULTS

Among the 11 patients, 5 patients were female; the median age was 61 (range, 43-79) years. The median treatment duration with anti-EGFR mAb before Shiunko initiation was 13.1 (range, 6-52) weeks. Skin moisturizer and topical steroids were applied for skin fissures in 11 and 5 patients, respectively. All patients had grade 2 skin fissures at baseline of Shiunko initiation. Two weeks after Shiunko initiation, complete recovery was noted in 4 patients and improvement to grade 1 was noted in 6 patients. There were no Shiunko-related adverse events. Ten patients continued anti-EGFR mAb treatment until disease progression, while 1 patient discontinued anti-EGFR mAb treatment due to severe eruptions.

CONCLUSION

Shiunko could be a treatment option for anti-EGFR mAb-induced skin fissure. Further studies are warranted to investigate the efficacy and safety of Shiunko for anti-EGFR mAb-induced skin fissure.

Maintenance strategies after anti-EGFR-based induction in metastatic colorectal cancer: A systematic review and bayesian network meta-analysis

BACKGROUND

In RAS wild type (wt) metastatic colorectal cancer (mCRC) maintenance therapy after induction with fluoropyrimidine (FP)-based cytotoxic therapy (CT) plus anti-EGFR agents is controversial.

METHODS

Phase II-III randomized trials were included. Maintenance strategies considered were: observation, anti-EGFR or FP monotherapy, FP + anti-EGFR, doublet CT + anti-EGFR.

RESULTS

Maintenance with FP + anti-EGFR (HR 0.56, 95% CrI 0.36-0.89) showed the greatest PFS benefit compared to observation, ranking first on SUCRA analysis (96.4%). Considering OS, doublet CT+ anti-EGFR, FP + anti-EGFR and anti-EGFR monotherapy yielded similar results. For PFS, FP + anti-EGFR confirmed to be valuable in BRAF wt patients and left sided tumors. In left sided tumors, the OS benefit of adding CT was limited. FP plus anti-EGFR showed a favourable safety profile compared to doublet CT + anti-EGFR.

CONCLUSIONS

FP + anti-EGFR can be considered a valuable maintenance option in RAS wt mCRC. EGFR monotherapy can be considered, especially in left-sided tumors.

Optimizing the first-line treatment for metastatic colorectal cancer

Colorectal cancer represents an important oncological challenge both for its incidence, which makes it an important health problem, and for its biological complexity, which has made clinical results very difficult in terms of outcome for this category of patients. To date these diseases should not be treated as a single entity but it is necessary to distinguish colorectal cancers based on characteristics that nowadays are essential to have greater therapeutic benefits. These include the sideness of the disease, the state of microsatellites, the presence of prognostic and predictive mutations of response to treatments currently available in clinical practice, which are associated with new therapeutic targets. The greatest challenge in the future will be to circumvent the resistance mechanisms that make this disease very difficult to treat with good long-term results by studying effective combination treatments with a good toxicity profile. Once such combinations or targeted treatments are consolidated, it will be desirable to shift the best therapies to the first line treatment to make them immediately accessible to the patient. It will also be essential to refine the selection of patients who can benefit from these treatments.

Maintenance Therapy With Cetuximab After FOLFIRI Plus Cetuximab for RAS Wild-Type Metastatic Colorectal Cancer: A Phase 2 Randomized Clinical Trial

Importance

The optimal maintenance strategy after induction chemotherapy with anti-epidermal growth factor receptor antibody for patients with RAS wild-type metastatic colorectal cancer (mCRC) remains to be debated.

Objective

To evaluate the efficacy and safety of maintenance therapy with single-agent cetuximab after FOLFIRI (leucovorin [folinic acid], fluorouracil, and irinotecan) plus cetuximab induction therapy.

Design, Setting, and Participants

The TIME (Treatment After Irinotecan-Based Frontline Therapy: Maintenance With Erbitux]) (PRODIGE 28 [Partenariat de Recherche en Oncologie Digestive]-UCGI 27 [UniCancer GastroIntestinal Group]) phase 2 noncomparative, multicenter randomized clinical trial was conducted from January 15, 2014, to November 23, 2018, among 139 patients with unresectable RAS wild-type mCRC. The cutoff date for analysis was July 21, 2022.

Interventions

After first-line induction therapy with 8 cycles of FOLFIRI plus cetuximab, patients without disease progression were randomized (1:1) to biweekly maintenance with cetuximab or observation. On disease progression, the same induction regimen was recommended for 16 weeks followed by further maintenance with cetuximab or observation until disease progression under the full induction regimen.

Main Outcomes and Measures

The primary end point was the 6-month progression-free rate from randomization. Analysis was performed on an intention-to-treat basis. An exploratory biomolecular analysis, using next-generation sequencing, investigated the putative prognostic value of the tumor mutation profile.

Results

Of 214 patients enrolled (141 men [65.9%]; median age, 67 years [range, 23-85 years]), 139 were randomized to receive cetuximab (n = 67; 45 men [67.2%]; median age, 64 years [range, 34-85 years]) or to be observed (n = 72; 50 men [69.4%]; median age, 68 years [23-85 years]). The 6-month progression-free rate was 38.8% ([26 of 67] 95% CI, 27.1%-51.5%) in the cetuximab group and 5.6% ([4 of 72] 95% CI, 1.5%-13.6%) in the observation group. At a median follow-up of 40.5 months (95% CI, 33.6-47.5 months), median progression-free survival (PFS) from randomization was 5.3 months (95% CI, 3.7-7.4 months) in the cetuximab group and 2.0 months (95% CI, 1.8-2.7 months) in the observation group. Median overall survival (OS) was 24.8 months (95% CI, 18.7-30.4 months) in the cetuximab group and 19.7 months (95% CI, 13.3-24.4 months) in the observation group. In an exploratory multivariate analysis, any tumor-activating mutation in the mitogen-activated protein kinase (MAPK) pathway genes was associated with shorter PFS from randomization regardless of treatment group (hazard ratio, 1.63 [95% CI, 1.01-2.62]; P = .04). The most frequent grade 3 or 4 treatment-related toxic effect in the cetuximab group during maintenance therapy was rash (8 of 67 [11.9%]).

Conclusion and Relevance

The randomized clinical trial did not meet its primary end point but suggests clinically meaningful PFS and OS benefits associated with cetuximab maintenance therapy. However, maintenance cetuximab or treatment breaks after first-line combination FOLFIRI-cetuximab therapy seems inappropriate for patients with MAPK-mutated independently of the side of primary tumor. A more complete assessment of MAPK pathway mutations warrants further investigation to the refine treatment strategy for patients with RAS wild-type mCRC.

Trial Registration

ClinicalTrials.gov Identifier: NCT02404935.

GART Functions as a Novel Methyltransferase in the RUVBL1/β-Catenin Signaling Pathway to Promote Tumor Stemness in Colorectal Cancer

Tumor stemness is associated with the recurrence and incurability of colorectal cancer (CRC), which lacks effective therapeutic targets and drugs. Glycinamide ribonucleotide transformylase (GART) fulfills an important role in numerous types of malignancies. The present study aims to identify the underlying mechanism through which GART may promote CRC stemness, as to developing novel therapeutic methods. An elevated level of GART is associated with poor outcomes in CRC patients and promotes the proliferation and migration of CRC cells. CD133+ cells with increased GART expression possess higher tumorigenic and proliferative capabilities both in vitro and in vivo. GART is identified to have a novel methyltransferase function, whose enzymatic activity center is located at the E948 site. GART also enhances the stability of RuvB-like AAA ATPase 1 (RUVBL1) through methylating its K7 site, which consequently aberrantly activates the Wnt/β-catenin signaling pathway to induce tumor stemness. Pemetrexed (PEM), a compound targeting GART, combined with other chemotherapy drugs greatly suppresses tumor growth both in a PDX model and in CRC patients. The present study demonstrates a novel methyltransferase function of GART and the role of the GART/RUVBL1/β-catenin signaling axis in promoting CRC stemness. PEM may be a promising therapeutic agent for the treatment of CRC.

Optimal maintenance strategy following FOLFOX plus anti-EGFR induction therapy in patients with RAS wild type metastatic colorectal cancer: An individual patient data pooled analysis of randomised clinical trials

BACKGROUND

Anti-EGFR antibodies plus doublet chemotherapy is the standard of care in RAS/BRAF wild-type metastatic colorectal cancer (mCRC). No phase-3 level of evidence is available to guide treatment de-escalation after anti-EGFR-based first-line. Several randomised clinical trials investigated de-intensification strategies with 5-fluorouracil/leucovorin (5-FU/LV) and/or anti-EGFR.

METHODS

We performed an individual patient data pooled analysis of Valentino, Panama, MACRO-2, COIN-B trials including RAS wild-type mCRC patients who received first-line therapy with FOLFOX plus panitumumab or cetuximab followed by pre-specified maintenance strategy. Only patients who started maintenance according to the assigned arm were included. Patients were categorised by type of maintenance (i.e. 5-FU/LV, anti-EGFR or 5-FU/LV + anti-EGFR). Progression-free survival (PFS) and overall survival (OS) were calculated from the start of maintenance; toxicity was evaluated for the maintenance treatment period.

RESULTS

A total of 518 patients were included in the pooled analysis. Overall, 123, 185 and 210 patients received maintenance with 5-FU/LV, anti-EGFR, 5-FU/LV + anti-EGFR, respectively. Median PFS was 5.6, 6.0 and 9.0 (P = 0.009) and OS was 25.7, 24.0 and 28.0 months (P = 0.134) in 5-FU/LV, anti-EGFR and 5-FU/LV + anti-EGFR arms, respectively. Monotherapy maintenance (either 5-FU/LV or anti-EGFR) was inferior to combination in terms of PFS (hazard ratios [HR] 1.26, P = 0.016) and non-significantly trending also in OS (HR 1.20, P = 0.111). An increase of overall any grade and grade ≥ 3 AEs and selected AEs was reported in combination compared to either 5-FU/LV or anti-EGFR arms.

CONCLUSIONS

This pooled analysis including four randomised phase II supports the use of 5-FU/LV plus anti-EGFR as the preferred maintenance regimen. Data provide rational for a more individualised maintenance treatment approach based on tumour and patients features.

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.

Adverse events during first-line treatments for mCRC: The Toxicity over Time (ToxT) analysis of three randomised trials

BACKGROUND

In clinical trials, the assessment of safety is traditionally focused on the overall rate of high-grade and serious adverse events (AEs). A new approach to AEs evaluation, taking into account chronic low-grade AEs, single patient's perspective, and time-related information, such as ToxT analysis, should be considered especially for less intense but potentially long-lasting treatments, such as maintenance strategies in metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

We applied ToxT (Toxicity over Time) evaluation to a large cohort of mCRC patients enroled in randomised TRIBE, TRIBE2, and VALENTINO studies, in order to longitudinally describe AEs throughout the whole treatment duration and to compare AEs evolution over cycles between induction and maintenance strategies, providing numerical and graphical results overall and per single patient. After 4-6 months of combination therapy, 5-fluorouracil/leucovorin (5-FU/LV) + bevacizumab or panitumumab was recommended in all studies except for the 50% of patients in the VALENTINO trial who received panitumumab alone.

RESULTS

Out of 1400 patients included, 42% received FOLFOXIRI (5-FU/LV, oxaliplatin, and irinotecan)/bevacizumab, 18% FOLFIRI/bevacizumab, 24% FOLFOX/bevacizumab, 16% FOLFOX/panitumumab. Mean grade of general and haematological AEs was higher in the first cycles, then progressively decreasing after the end of induction (p < 0.001), and always remaining at the highest levels with FOLFOXIRI/bevacizumab (p < 0.001). Neurotoxicity became more frequent over the cycles with late high-grade episodes (p < 0.001), while the incidence but not the grade of hand-and-foot syndrome gradually increased (p = 0.91). Anti-VEGF-related AEs were more severe in the first cycles, then setting over at low levels (p = 0.03), while anti-EGFR-related AEs still affected patients during maintenance.

CONCLUSIONS

Most of chemotherapy-related AEs (except for HFS and neuropathy) reach the highest level in the first cycles, then decrease, probably due to their active clinical management. Transition to maintenance allows relief from most AEs, especially with bevacizumab-based regimens, while anti-EGFR-related AEs may persist.

Maintenance therapy with Fluoropyrimidine and cetuximab or bevacizumab after first line FOLFOX-chemotherapy in metastatic colorectal cancer according to RAS or BRAFV600E mutation status

PURPOSE

Fluoropyrimidine (FP) with oxaliplatin-based chemotherapy is the standard first-line treatment for metastatic colorectal cancer (mCRC); however, oxaliplatin-induced neuropathy critically affects the quality of life of patients. Maintenance strategies with FP plus bevacizumab have been well-established; nonetheless, the real-world outcomes of maintenance therapy with FP and cetuximab are unclear. We investigated the clinical outcomes of patients who underwent maintenance therapy with cetuximab.

METHODS

We retrospectively identified and analyzed patients with mCRC who were treated between 2012 and 2021 with first-line oxaliplatin-based induction chemotherapy (IC) plus biologic agents (either cetuximab or bevacizumab), and underwent maintenance therapy (IC regimen without oxaliplatin) after IC.

RESULTS

In total, 19 patients who were treated with mFOLFOX6 (FP/leucovorin/oxaliplatin) with cetuximab, and 26 patients who were treated with mFOLFOX6 with bevacizumab were included. In the cetuximab group, all patients were KRAS-, NRAS-, and BRAF-wild type, whereas most patients in the bevacizumab group harbored KRAS or BRAFV600E or NRAS mutants. During the maintenance treatment, seven patients (four [21%] in the cetuximab group and three [11%] in the bevacizumab group) achieved partial response after achieving nadir during induction chemotherapy. The disease control rates of maintenance therapy were 79% and 74% in the cetuximab and bevacizumab groups, respectively. The median progression-free survival of maintenance therapy and overall survival was 5.98 months and 32.4 months in the cetuximab group, and 4.83 months and 25.6 months in the bevacizumab group, respectively.

CONCLUSIONS

Maintenance therapy with FP plus biologic agents (either bevacizumab or cetuximab) is a feasible strategy for appropriate mCRC patients according to their RAS/BRAF status. Further large-scale randomized studies are needed to validate the efficacy of anti-epidermal growth factor receptor-based maintenance therapy.

Impact of sex on the efficacy and safety of panitumumab plus fluorouracil and folinic acid versus fluorouracil and folinic acid alone as maintenance therapy in RAS WT metastatic colorectal cancer (mCRC). Subgroup analysis of the PanaMa-study (AIO-KRK-0212)

BACKGROUND

Clinical trials in metastatic colorectal cancer (mCRC) are usually conducted irrespective of sex. Sex-associated differences relating to safety and efficacy in the treatment of mCRC, however, are gaining interest.

METHODS

PanaMa investigated the efficacy of panitumumab (Pmab) plus fluorouracil and folinic acid (FU/FA) versus FU/FA alone after induction therapy with six cycles of FU/FA and oxaliplatin plus Pmab in patients with RAS wild-type mCRC. In this post hoc analysis, the study population was stratified for sex. Evaluated efficacy endpoints during maintenance treatment were progression-free survival (PFS, primary endpoint of the trial), overall survival (OS) and objective response rate during maintenance therapy. Safety endpoints were rates of any grade and grade 3/4 adverse events during maintenance therapy.

RESULTS

In total, 165 male and 83 female patients were randomized and treated. Male and female patients showed numerically better objective response rates with Pmab, without reaching statistical significance. Male patients derived a significant benefit from the addition of Pmab to maintenance treatment with regard to PFS [hazard ratio (HR) 0.63; 95% confidence interval (CI) 0.45-0.88; P = 0.006] that was not observed in female patients (HR 0.85; 95% CI 0.53-1.35; P = 0.491). The better PFS for male patients treated with Pmab did not translate into improved OS (HR 0.85; 95% CI 0.55-1.30; P = 0.452). Female patients showed numerically improved OS when treated with Pmab. There was no difference in the total of grade ≥3 adverse events during maintenance regarding sex (P = 0.791). Female patients, however, had a higher rate of any grade nausea, diarrhea and stomatitis.

CONCLUSIONS

In the PanaMa trial, the addition of Pmab to maintenance treatment of RAS wild-type mCRC with FU/FA improved the outcome in terms of the primary endpoint (PFS) particularly in male patients. Female patients did not show the same benefit while experiencing higher rates of adverse events. Our results support the development of sex-specific protocols.

Health-related quality of life in patients with RAS wild-type metastatic colorectal cancer treated with fluorouracil and folinic acid with or without panitumumab as maintenance therapy: a prespecified secondary analysis of the PanaMa (AIO KRK 0212) trial

BACKGROUND

The PanaMa trial demonstrated significant benefit in progression-free survival with the addition of panitumumab (Pmab) to fluorouracil and folinic acid (FU/FA) as maintenance therapy following first-line induction therapy with FOLFOX/Pmab in patients with RAS wild-type metastatic colorectal cancer. Here, we report health-related quality of life (HRQOL) analyses from the PanaMa trial.

METHODS

HRQOL outcomes were evaluated using European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) at every cycle of therapy until disease progression/death. HRQOL outcomes were mean and individual changes in EORTC QLQ-C30 from baselines (before induction therapy and before maintenance therapy) to each cycle of treatment. Comparative analyses were performed by randomisation status and treatment arm for induction- and maintenance-therapy, respectively. The trial is registered with clinicaltrials.gov (NCT01991873).

RESULTS

At least one HRQOL questionnaire was completed by a total of 349/377 (93%) patients who received induction therapy, and by 237/248 (96%) patients who were randomised and received maintenance therapy. During induction therapy, most HRQOL dimensions remained stable or showed improvement, while appetite loss and diarrhoea significantly deteriorated. During maintenance therapy, HRQOL dimensions remained stable, while those that deteriorated during induction therapy showed significant improvement, without significant differences between the treatment arms.

CONCLUSION

Maintenance therapy improves HRQOL dimensions that initially deteriorated during induction therapy while stabilising HRQOL in other dimensions. The addition of Pmab to FU/FA as maintenance therapy in patients with RAS wild-type metastatic colorectal cancer prolongs progression-free survival without negative impact on HRQOL.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with metastatic colorectal cancer

The European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with metastatic colorectal cancer (mCRC), published in late 2022, were adapted in December 2022, according to previously established standard methodology, to produce the Pan-Asian adapted (PAGA) ESMO consensus guidelines for the management of Asian patients with mCRC. The adapted guidelines presented in this manuscript represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with mCRC representing the oncological societies of China (CSCO), Indonesia (ISHMO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO), co-ordinated by ESMO and the Japanese Society of Medical Oncology (JSMO). The voting was based on scientific evidence and was independent of the current treatment practices, drug access restrictions and reimbursement decisions in the different Asian countries. The latter are discussed separately in the manuscript. The aim is to provide guidance for the optimisation and harmonisation of the management of patients with mCRC across the different countries of Asia, drawing on the evidence provided by both Western and Asian trials, whilst respecting the differences in screening practices, molecular profiling and age and stage at presentation, coupled with a disparity in the drug approvals and reimbursement strategies, between the different countries.

Consensus Molecular Subtypes as Biomarkers of Fluorouracil and Folinic Acid Maintenance Therapy With or Without Panitumumab in RAS Wild-Type Metastatic Colorectal Cancer (PanaMa, AIO KRK 0212)

PURPOSE

Consensus molecular subtypes (CMSs) were evaluated as prognostic and predictive biomarkers of patients with RAS wild-type metastatic colorectal cancer (mCRC) receiving fluorouracil and folinic acid (FU/FA) with or without panitumumab (Pmab) after Pmab + mFOLFOX6 induction within the randomized phase II PanaMa trial.

METHODS

CMSs were determined in the safety set (ie, patients that received induction) and full analysis set (FAS; ie, randomly assigned patients who received maintenance) and correlated with median progression-free survival (PFS) and overall survival (OS) since the start of induction or maintenance treatment and objective response rates (ORRs). Hazard ratios (HRs) and 95% CI were calculated by univariate/multivariate Cox regression analyses.

RESULTS

Of 377 patients of the safety set, 296 (78.5%) had available CMS data: CMS1/2/3/4: 29 (9.8%)/122 (41.2%)/33 (11.2%)/112 (37.8%) and unclassifiable: 17 (5.7%). The CMSs were prognostic biomarkers in terms of PFS (P < .0001), OS (P < .0001), and ORR (P = .02) since the start of induction treatment. In FAS patients (n = 196), with CMS2/4 tumors, the addition of Pmab to FU/FA maintenance therapy was associated with longer PFS (CMS2: HR, 0.58 [95% CI, 0.36 to 0.95], P = .03; CMS4: HR, 0.63 [95% CI, 0.38 to 1.03], P = .07) and OS (CMS2: HR, 0.88 [95% CI, 0.52 to 1.52], P = .66; CMS4: HR, 0.54 [95% CI, 0.30 to 0.96], P = .04). The CMS interacted significantly with treatment in terms of PFS (CMS2 v CMS1/3: P = .02; CMS4 v CMS1/3: P = .03) and OS (CMS2 v CMS1/3: P = .03; CMS4 v CMS1/3: P < .001).

CONCLUSION

The CMS had a prognostic impact on PFS, OS, and ORR in RAS wild-type mCRC. In PanaMa, Pmab + FU/FA maintenance was associated with beneficial outcomes in CMS2/4, whereas no benefit was observed in CMS1/3 tumors.

Stage IV Colorectal Cancer Management and Treatment

(1) Background: Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related mortality worldwide. Up to 50% of patients with CRC develop metastatic CRC (mCRC). Surgical and systemic therapy advances can now offer significant survival advantages. Understanding the evolving treatment options is essential for decreasing mCRC mortality. We aim to summarize current evidence and guidelines regarding the management of mCRC to provide utility when making a treatment plan for the heterogenous spectrum of mCRC. (2) Methods: A comprehensive literature search of PubMed and current guidelines written by major cancer and surgical societies were reviewed. The references of the included studies were screened to identify additional studies that were incorporated as appropriate. (3) Results: The standard of care for mCRC primarily consists of surgical resection and systemic therapy. Complete resection of liver, lung, and peritoneal metastases is associated with better disease control and survival. Systemic therapy now includes chemotherapy, targeted therapy, and immunotherapy options that can be tailored by molecular profiling. Differences between colon and rectal metastasis management exist between major guidelines. (4) Conclusions: With the advances in surgical and systemic therapy, as well as a better understanding of tumor biology and the importance of molecular profiling, more patients can anticipate prolonged survival. We provide a summary of available evidence for the management of mCRC, highlighting the similarities and presenting the difference in available literature. Ultimately, a multidisciplinary evaluation of patients with mCRC is crucial to selecting the appropriate pathway.

Delphi Initiative for Early-Onset Colorectal Cancer (DIRECt) International Management Guidelines

BACKGROUND & AIMS

Patients with early-onset colorectal cancer (eoCRC) are managed according to guidelines that are not age-specific. A multidisciplinary international group (DIRECt), composed of 69 experts, was convened to develop the first evidence-based consensus recommendations for eoCRC.

METHODS

After reviewing the published literature, a Delphi methodology was used to draft and respond to clinically relevant questions. Each statement underwent 3 rounds of voting and reached a consensus level of agreement of ≥80%.

RESULTS

The DIRECt group produced 31 statements in 7 areas of interest: diagnosis, risk factors, genetics, pathology-oncology, endoscopy, therapy, and supportive care. There was strong consensus that all individuals younger than 50 should undergo CRC risk stratification and prompt symptom assessment. All newly diagnosed eoCRC patients should receive germline genetic testing, ideally before surgery. On the basis of current evidence, endoscopic, surgical, and oncologic treatment of eoCRC should not differ from later-onset CRC, except for individuals with pathogenic or likely pathogenic germline variants. The evidence on chemotherapy is not sufficient to recommend changes to established therapeutic protocols. Fertility preservation and sexual health are important to address in eoCRC survivors. The DIRECt group highlighted areas with knowledge gaps that should be prioritized in future research efforts, including age at first screening for the general population, use of fecal immunochemical tests, chemotherapy, endoscopic therapy, and post-treatment surveillance for eoCRC patients.

CONCLUSIONS

The DIRECt group produced the first consensus recommendations on eoCRC. All statements should be considered together with the accompanying comments and literature reviews. We highlighted areas where research should be prioritized. These guidelines represent a useful tool for clinicians caring for patients with eoCRC.

Heterogeneous disease and intermittent treatment in metastatic colorectal cancer: A case report

Background

Metastatic colorectal cancer is one of the most common causes of cancer death worldwide. RAS and BRAF mutational analyses are strongly recommended before beginning chemotherapy in the metastatic setting for their predictive role for the efficacy of anti-EGFR monoclonal antibodies. In most of cases, mutational status coincides between primary tumor and metastases. In RAS and BRAF wild-type patients treated with anti-EGFRs, after an induction treatment period, recent evidence supports the role of a maintenance treatment with fluoropyrimidines and anti-EGFRs. However, skin toxicity is the most described and limiting side-effect of maintenance. Moreover, it is described that the continuous administration of these monoclonal antibodies leads to an acquired resistance to anti-EGFRs, with subsequent treatment failure. Intermittent strategy with chemotherapy plus anti-EGFR may help maintain treatment efficacy, delaying resistance.

Case presentation

In this case report, we describe the case of a RAS-BRAF wild-type elderly patient undergoing first-line chemotherapy with FOLFOX + panitumumab, reporting response of disease on all metastatic sites except for a node. This node, surgically removed, revealed host BRAF V600 mutant clones. After surgery, patient continued chemotherapy with a stop-and-go strategy continuing to benefit from the same drugs after 4 years since diagnosis, and continuing to achieve response when on treatment, avoiding unacceptable anti-EGFR toxicity. This patient, still alive after 6 years since the diagnosis, represents the case of a good synergy between molecular profiling of disease, surgery, and intermittent treatment.

New developments in targeted therapy for metastatic colorectal cancer

Colorectal cancer (CRC) is the second most lethal cancer worldwide and the prognosis of metastatic CRC (mCRC) remains poor. Recent advancements in translational research have led to the identification of several new therapeutic targets and improved the treatment outcome of patients with tumours harbouring BRAF V600E mutation, (HER2) ErBB2 alterations, NTRK gene fusions and KRAS(G12C) mutation. Improved understanding towards the mechanism of resistance to targeted therapy such as anti-epidermal growth factor receptor antibodies and the evolving role of therapeutic monitoring with circulating tumour DNA (ctDNA) has enabled the longitudinal tracking of clonal evolution during treatment and the individualization of subsequent treatments. To broaden the community-based implementation of precision oncology in directing targeted therapies for patients with gastrointestinal cancers including mCRC, the feasibility of 'Master Protocols' that utilizes ctDNA-based genotyping platforms is currently being evaluated. Such protocols encompass both observational and interventional clinical trials of novel targeted therapies conducted within a large clinical trial network. In this review, we will discuss the latest developments in targeted therapies, and therapeutic strategies for overcoming acquired drug resistance in patients with mCRC.

Depth of response of induction therapy and consecutive maintenance treatment in patients with RAS wild-type metastatic colorectal cancer: An analysis of the PanaMa trial (AIO KRK 0212)

BACKGROUND

In patients with RAS wild-type metastatic colorectal cancer, depth of response (DpR) has gained importance as a novel end-point in clinical trials. We investigated the overall DpR, as well as the prognostic and predictive impact of DpR to induction therapy (six cycles of 5-fluorouracil, leucovorin [FU/FA], oxaliplatin [FOLFOX] and panitumumab [Pmab]) on consecutive maintenance therapy (FU/FA plus Pmab or FU/FA alone) in patients treated within the PanaMa trial.

METHODS

Central radiological assessment was performed according to RECIST 1.1. DpR was defined as percentage change in tumour diameter within defined time intervals (induction therapy, maintenance therapy, total course of therapy). For prognostic and predictive analyses, median DpR (</≥) served as threshold.

RESULTS

Out of 248 patients receiving maintenance therapy, 211 were evaluable for DpR analyses (FU/FA + Pmab, n = 106; FU/FA alone, n = 105). The overall DpR in all patients was 56.5%. DpR of induction therapy (42.5%) accounted for the largest proportion (75.2%) of the overall DpR. While greater DpR to induction therapy was significantly associated with prolonged PFS (HR 0.70, 95% CI 0.52-0.93, p = 0.013) and OS (HR 0.38, 95% CI 0.28-0.51, p < 0.001), there was no significant correlation of DpR and maintenance treatment arm.

CONCLUSIONS

In the PanaMa trial, the overall DpR was similar to DpR achieved by other epidermal growth factor receptor-based regimens. DpR to induction therapy accounted for three quarters of the total tumour shrinkage potentially suggesting that FOLFOX plus Pmab can be de-escalated following induction without substantially compromising efficacy. DpR to induction therapy was prognostic but not predictive for efficacy of consecutive maintenance therapy.

CLINICAL TRIAL INFORMATION

NCT01991873.

Recent and Future Strategies to Overcome Resistance to Targeted Therapies and Immunotherapies in Metastatic Colorectal Cancer

Colorectal cancer (CRC) is the third most common cause of cancer-related deaths worldwide, and 20% of patients with CRC present at diagnosis with metastases. The treatment of metastatic CRC is based on a fluoropyrimidine-based chemotherapy plus additional agents such as oxaliplatin and irinotecan. To date, on the basis of the molecular background, targeted therapies (e.g., monoclonal antibodies against epidermal growth factor receptor or inhibiting angiogenesis) are administered to improve the treatment of metastatic CRC. In addition, more recently, immunological agents emerged as effective in patients with a defective mismatch repair system. The administration of targeted therapies and immunotherapy lead to a significant increase in the survival of patients; however these drugs do not always prove effective. In most cases the lack of effectiveness is due to the development of primary resistance, either a resistance-inducing factor is already present before treatment or resistance is acquired when it occurs after treatment initiation. In this review we describe the most relevant targeted therapies and immunotherapies and expand on the reasons for resistance to the different approved or under development targeted drugs. Then we showed the possible mechanisms and drugs that may lead to overcoming the primary or acquired resistance in metastatic CRC.

Current concepts of anti-EGFR targeting in metastatic colorectal cancer

Anti-EGFR targeting is one of the key strategies in the treatment of metastatic colorectal cancer (mCRC). For almost two decades oncologists have struggled to implement EGFR antibodies in the mCRC continuum of care. Both sidedness and RAS mutational status rank high among the predictive factors for the clinical efficacy of EGFR inhibitors. A prospective phase III trial has recently confirmed that anti-EGFR targeting confers an overall survival benefit only in left sided RAS-wildtype tumors when given in first line. It is a matter of discussion if more clinical benefit can be reached by considering putative primary resistance mechanisms (e.g., HER2, BRAF, PIK3CA, etc.) at this early stage of treatment. The value of this procedure in daily routine clinical utility has not yet been clearly delineated. Re-exposure to EGFR antibodies becomes increasingly crucial in the disease journey of mCRC. Yet re- induction or re-challenge strategies have been problematic as they relied on mathematical models that described the timely decay of EGFR antibody resistant clones. The advent of liquid biopsy and the implementation of more accurate next-generation sequencing (NGS) based high throughput methods allows for tracing of EGFR resistant clones in real time. These displays the spatiotemporal heterogeneity of metastatic disease compared to the former standard radiographic assessment and re-biopsy. These techniques may move EGFR inhibition in mCRC into the area of precision medicine in order to apply EGFR antibodies with the increase or decrease of EGFR resistant clones. This review critically discusses established concepts of tackling the EGFR pathway in mCRC and provides insight into the growing field of liquid biopsy guided personalized approaches of EGFR inhibition in mCRC.

Survival for patients with metastatic colon cancer underwent cytoreductive colectomy in the era of rapid development of anticancer drugs: A real-world analysis based on updated population dataset of 2004-2018

Objective: Metastatic colon cancer (mCC) poses a great threat to the survival of patients suffering from it. In the past decade, many clinical trials have been carried out to improve the prognosis of patients with mCC. Numerous treatments have emerged, and satisfactory efficacy has been demonstrated in randomized phase III trials in highly selective patients with mCC. Our present study aims to investigate whether these therapeutic advances can be reflected to the broader mCC patients who performed cytoreductive colectomy. Method: General and prognostic data for patients diagnosed with mCC who underwent cytoreductive colectomy between 2004-2018 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Survival was analyzed using the Kaplan-Meier method and Cox proportional hazards model. The hazard ratio (HR) and its 95% confidence interval (CI) were used to evaluate the influence of risk factors on prognosis. Results: A total of 26,301 patients diagnosed with mCC treated with cytoreductive colectomy were included in this study. The median overall survival was 19 months (range, 17-23). The good prognosis was associated with patients diagnosed at the most recent year, younger age, non-black race, female, married, without previous history of malignancy, no second malignancy onset, descending/sigmoid/splenic flexure colon tumor, normal CEA levels at diagnosis, low primary tumor burden, T1/T2 stage, N0 stage, single organ metastasis, underwent surgical resection of synchronous distant metastatic lymph nodes or organs, a high number of lymph-node examinations, low positive lymph-node ratio and received adjuvant chemotherapy. The proportion of patients surviving for ≥24 months increased from 37% in 2004 to 44.2% in 2016 (p < 0.001), especially in ≤49 years patients [46.8% in 2004 to 57.8% in 2016 (p < 0.001)]. The percentage of patients who died within 3 months decreased between 2004 and 2018 (from 19.6% to 15.7%; p < 0.001). Conclusion: Over a span of 15 years, the long-term survival has improved in real-world mCC patients who were treated with cytoreductive colectomy, especially among younger patients. However, the median overall survival remains not substantial.

Spend less to achieve more: Economic analysis of intermittent versus continuous cetuximab in KRAS wild-type patients with metastatic colorectal cancer

BACKGROUND

In 2014, the COIN-B clinical trial demonstrated that intermittent cetuximab (IC) was a safe alternative to continuous cetuximab (CC), with less cytotoxic chemotherapy, in first-line treatment for KRAS wild-type metastatic colorectal cancer (mCRC). Cetuximab has been available for this indication in England since 2015, but treatment breaks beyond 6 weeks were prohibited, despite real-world evidence that therapy de-escalation maintains equivalent disease control, but with superior Quality-of-Life (QoL). We performed health economic analyses of IC versus CC and used this evidence to help underpin policy change and guide clinical practice through reduction in unnecessary treatment for mCRC patients.

METHODS

Employing cost-minimization analysis, we conducted partitioned survival modelling (PSM) and Markov Chain Monte-Carlo (MCMC) simulation to determine costs and quality-adjusted-life-years for IC versus CC.

RESULTS

IC reduced costs by £ 35,763 (PSM; p < 0.001) or £ 30,189 (MCMC) per patient annually, while preserving treatment efficacy and enhancing QoL. Extrapolating to all mCRC patients eligible for cetuximab therapy would have generated cost savings of ~£ 1.2 billion over this cohort's lifetime. These data helped underpin a request to NHS England to remove treatment break restrictions in first-line mCRC therapy, which has been adopted as an interim treatment option policy in colorectal cancer during the Covid-19 pandemic.

CONCLUSIONS

Our results highlight substantial cost savings achievable by treatment de-escalation, while also reinforcing the importance of therapy breaks to potentially increase tumour responsiveness and reduce treatment toxicity. Our study also highlights how health economic evidence can influence health policy, championing reduced treatment intensity approaches without compromising patient outcomes, which is of particular relevance when addressing the reduced capacity and treatment backlogs experienced during the pandemic.

FOLFOX plus panitumumab or FOLFOX alone as additive therapy following R0/1 resection of RAS wild-type colorectal cancer liver metastases - The PARLIM trial (AIO KRK 0314)

PURPOSE

This trial investigates the addition of panitumumab to chemotherapy with fluorouracil/folinic acid and oxaliplatin (FOLFOX) in a 2:1 randomised, controlled, open-label, phase II trial in RAS wild-type colorectal cancer patients with R0/1-resected liver metastases.

EXPERIMENTAL DESIGN

The primary endpoint was progression-free survival (PFS) two years after randomisation. The experimental arm (12 weeks of biweekly mFOLFOX6 plus panitumumab followed by 12 weeks of panitumumab alone) was considered active if the two-year PFS rate was ≥65%. Based on historical data, a two-year PFS rate of 50% was estimated in the control arm (12 weeks of biweekly FOLFOX). The trial was performed with a power of 80% and an alpha of 0.05. Secondary endpoints included overall survival (OS) and toxicity. The trial is registered with ClinicalTrials.gov, NCT01384994.

RESULTS

The full analysis set consists of 70 patients (pts) in the experimental arm and 36 pts in the control arm. The primary endpoint was missed with a two-year PFS of 35.7% with FOLFOX plus panitumumab and 30.6% in the control arm. In comparative analyses, trends towards improved PFS (HR 0.83; 95%CI, 0.52-1.33; P = 0.44) and OS (HR 0.70; 95% CI, 0.34-1.46; P = 0.34) were observed in favour of the panitumumab-based study arm. No new or unexpected safety signals were observed with FOLFOX plus panitumumab following liver resection.

CONCLUSION

The PARLIM trial failed to demonstrate a two-year PFS rate of 65% after resection of colorectal liver metastases. The positive trends in survival endpoints may support future trials evaluating treatment with anti-EGFR agents after resection of liver metastases.

Clinical management of metastatic colorectal cancer in the era of precision medicine

Colorectal cancer (CRC) represents approximately 10% of all cancers and is the second most common cause of cancer deaths. Initial clinical presentation as metastatic CRC (mCRC) occurs in approximately 20% of patients. Moreover, up to 50% of patients with localized disease eventually develop metastases. Appropriate clinical management of these patients is still a challenging medical issue. Major efforts have been made to unveil the molecular landscape of mCRC. This has resulted in the identification of several druggable tumor molecular targets with the aim of developing personalized treatments for each patient. This review summarizes the improvements in the clinical management of patients with mCRC in the emerging era of precision medicine. In fact, molecular stratification, on which the current treatment algorithm for mCRC is based, although it does not completely represent the complexity of this disease, has been the first significant step toward clinically informative genetic profiling for implementing more effective therapeutic approaches. This has resulted in a clinically relevant increase in mCRC disease control and patient survival. The next steps in the clinical management of mCRC will be to integrate the comprehensive knowledge of tumor gene alterations, of tumor and microenvironment gene and protein expression profiling, of host immune competence as well as the application of the resulting dynamic changes to a precision medicine-based continuum of care for each patient. This approach could result in the identification of individual prognostic and predictive parameters, which could help the clinician in choosing the most appropriate therapeutic program(s) throughout the entire disease journey for each patient with mCRC. CA Cancer J Clin. 2022;72:000-000.

Early onset metastatic colorectal cancer in patients receiving panitumumab-based upfront strategy: Overall and sex-specific outcomes in the Valentino trial

Anti-EGFRs plus doublet chemotherapy is considered the optimal upfront option for RAS/BRAF wild-type left-sided metastatic colorectal cancer (mCRC). Early-onset (EO) mCRC has an increasing incidence and its prognostic/predictive role and management is debatable. We performed a post hoc analysis of Valentino study, that randomized RAS wild-type mCRC patients to two panitumumab-based maintenance regimens after FOLFOX/panitumumab induction. We assessed the safety and efficacy outcomes in patients stratified for age (<50/≥50 years old). We assessed progression-free survival (PFS), overall survival (OS), response rate (ORR), rate of treatment-related and panitumumab-related adverse events (AEs) and quality of life (QoL). In 229 patients enrolled, 35 (15%) had EO mCRC, with a higher rate of female sex (P = .020) and lower rate of primary tumor resection (P = .001). Median PFS and OS were 10.9 vs 10.8 months (P = .593) and 28.1 vs 27.5 months (P = .865) in patients <50 and ≥50 years old, respectively, with no significant impact of maintenance arm. ORR and disease control rate were 74% vs 65% (P = .337) and 97% vs 81% (P = .013) in patients <50 or ≥50 years old. In younger patients, a trend for increased chemotherapy-related AEs (peculiarly anemia) was shown, while significantly decreased EGFR-related hypomagnesemia and increased skin rash were reported. No significant differences in treatment intensity or QoL were observed. In patients with EO mCRC and RAS wild-type status, we found no differences in terms of survival outcomes based on age when selecting maintenance strategies. Management of treatment-related AEs should consider the differential toxicity profile of age and sex.

The Role of Anti-EGFR Monoclonal Antibody in mCRC Maintenance Therapy

Background: Epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs) combined with chemotherapy in patients with RAS (rat sarcoma viral oncogene homolog) wild-type metastatic colorectal cancer (mCRC) can alleviate and stabilize the disease, effectively prolong the progression-free survival (PFS) and overall survival (OS), and improve the overall response rate (ORR), which is the first-line treatment standard scheme for RAS wild-type mCRC currently. However, whether anti-EGFR mAb can be used for the maintenance treatment after the first-line treatment of mCRC remains controversial. We reviewed the recent studies on anti-EGFR mAb. The contents include five parts, introduction, anti-EGFR mAb in mCRC and its status in first-line therapy, establishment of the maintenance treatment pattern after the standard first-line treatment for mCRC, research progress of anti-EGFR mAb in mCRC maintenance therapy, and conclusion. More studies support the maintenance treatment of anti-EGFR mAb, but some researchers raise the problems about high cost and drug resistance. Despite lack of the maintenance evidence of anti-EGFR mAb, especially lack of large-scale phase III prospective clinical trials, with the emergence of new evidence and more accurate screening of treatment-dominant groups, maintenance therapy with anti-EGFR mAb monotherapy or anti-EGFR mAb combined with fluorouracil-based schemes after first-line chemotherapy combined with anti-EGFR mAb therapy might strive for more treatment opportunities, optimize treatment strategies and prolong treatment continuity, and finally, lead to more survival benefit for suitable patients.

Post-Induction Management in Patients With Left-Sided RAS and BRAF Wild-Type Metastatic Colorectal Cancer Treated With First-Line Anti-EGFR-Based Doublet Regimens: A Multicentre Study

Background

Few data regarding post-induction management following first-line anti-epidermal growth factor receptor (EGFR)-based doublet regimens in patients with left-sided RAS/BRAF wild-type metastatic colorectal cancer (mCRC) are available.

Methods

This multicenter, retrospective study aimed at evaluating clinicians’ attitude, and the safety and effectiveness of post-induction strategies in consecutive patients affected by left-sided RAS/BRAF wild-type mCRC treated with doublet chemotherapy plus anti-EGFR as first-line regimen, who did not experience disease progression within 6 months from induction initiation, at 21 Italian and 1 Spanish Institutions. The measured clinical outcomes were: progression-free survival (PFS), overall survival (OS), adverse events, and objective response rate (ORR).

Results

At the data cutoff, among 686 consecutive patients with left-sided RAS/BRAF wild-type mCRC treated with doublet plus anti-EGFR as first-line regimen from March 2012 to October 2020, 355 eligible patients have been included in the present analysis. Among these, 118 (33.2%), 66 (18.6%), and 11 (3.1%) received a maintenance with 5-fluorouracil/leucovorin (5FU/LV)+anti-EGFR, anti-EGFR, and 5FU/LV, respectively, while 160 (45.1%) patients continued induction treatment (non-maintenance) until disease progression, unacceptable toxicity, patient decision, or completion of planned treatment. The median period of follow-up for the overall population was 33.7 months (95%CI = 28.9–35.6). The median PFS values of the 5FU/LV+anti-EGFR, anti-EGFR, 5FU/LV, and non-maintenance cohorts were 16.0 (95%CI = 14.3–17.7, 86 events), 13.0 (95%CI = 11.4–14.5, 56 events), 14.0 (95%CI = 8.1–20.0, 8 events), and 10.1 months (95%CI = 9.0–11.2, 136 events), respectively (p < 0.001). The median OS values were 39.6 (95%CI = 31.5–47.7, 43 events), 36.1 (95%CI = 31.6–40.7, 36 events), 39.5 (95%CI = 28.2–50.8, 4 events), and 25.1 months (95%CI = 22.6–27.6, 99 events), respectively (p < 0.001). After adjusting for key covariates, a statistically significant improvement in PFS in favor of 5FU/LV+anti-EGFR (HR = 0.59, 95%CI = 0.44–0.77, p < 0.001) and anti-EGFR (HR = 0.71, 95%CI = 0.51–0.98, p = 0.039) compared to the non-maintenance cohort was found. Compared to the non-maintenance cohort, OS was improved by 5FU/LV+anti-EGFR (HR = 0.55, 95%CI = 0.38–0.81, p = 0.002) and, with marginal significance, by anti-EGFR (HR = 0.67, 95%CI = 0.51–0.98, p = 0.051). No difference was found in ORR. Any grade non-hematological and hematological events were generally higher in the non-maintenance compared to the maintenance cohorts.

Conclusion

Among the treatment strategies following an anti-EGFR-based doublet first-line induction regimen in patients affected by left-sided RAS/BRAF wild-type mCRC treated in a “real-life” setting, 5FU/LV+anti-EGFR resulted the most adopted, effective, and relatively safe regimen.