Cetuximab monotherapy and cetuximab plus irinotecan in irinotecan-refractory metastatic colorectal cancer

Targeting EGFR in Esophagogastric Cancer

Esophagogastric cancer (EGC) remains a major cause of cancer-related mortality. Overall survival in the metastatic setting remains poor, with few molecular targeted approaches having been successfully incorporated into routine care to-date: only first line anti-HER2 therapy in ERBB2-expressing tumors, second line anti-VEGFR2 therapy with ramucirumab in unselected patients, and pembrolizumab in PD-L1 expressing or MSI-H patients. EGFR inhibitors were extensively studied in EGC, including phase III trials with cetuximab (EXPAND), panitumumab (REAL3), and gefitinib (COG). All three trials were conducted in unselected populations, and therefore, failed to demonstrate clinical benefit. Here, we review previous attempts at targeting EGFR in EGC and potential future biomarkers for targeting this pathway in patients with EGFR-amplified tumors.

The role of IgE specific for galactose-α-1,3-galactose in predicting cetuximab induced hypersensitivity reaction: a systematic review and a diagnostic meta-analysis

Recombinant monoclonal antibodies are used for treating various diseases, from asthma, rheumatoid arthritis, and inflammatory bowel disease to cancer. Although monoclonal antibodies are known to have fewer toxic reactions compared with the conventional cytotoxic antineoplastic drugs, the cases of severe systemic hypersensitivity reaction (HSR) should be acknowledged. Our aim was to assess the diagnostic accuracy of the anti-IgE for galactose-α-1,3-galactose in patients with HSRs to cetuximab. We searched in PubMed, Cochrane Library, Scopus, and World of Science databases to July 1st, 2020. We included a total of 6 studies, with 1074 patients. Meta-analysis was performed using bivariate analysis and the random-effect model. The pooled sensitivity was 73% (95% CI 62-81%) and the pooled specificity was 88% (95% CI 79-94%). We had not found significant heterogeneity and, despite some discrepancies in the nature of data available in the analysed studies, we draw the conclusion that the presence of cetuximab specific IgE (anti cetuximab antibody) and/or galactose-α-1,3-galactose shows moderate to high sensitivity and specificity of developing an HSR. More studies are needed to establish a protocol necessary for the proper prediction and avoidance of HSR related to cetuximab.

Early stopping in seamless phase I/II clinical trials

In recent years, seamless phase I/II clinical trials have drawn much attention, as they consider both toxicity and efficacy endpoints in finding an optimal dose (OD). Engaging an appropriate number of patients in a trial is a challenging task. This paper attempts a dynamic stopping rule to save resources in phase I/II trials. That is, the stopping rule aims to save patients from unnecessary toxic or subtherapeutic doses. We allow a trial to stop early when widths of the confidence intervals for the dose-response parameters become narrower or when the sample size is equal to a predefined size, whichever comes first. The simulation study of dose-response scenarios in various settings demonstrates that the proposed stopping rule can engage an appropriate number of patients. Therefore, we suggest its use in clinical trials.

Treatments after first progression in metastatic colorectal cancer. A literature review and evidence-based algorithm

Prolonging survival, achieving symptoms palliation and preserving quality of life are the primary therapeutic goals of treatments administered after disease progression in mCRC. Even if the impact of these therapies on the prognosis of affected patients is less relevant than the impact of the upfront treatment, tailoring the optimal second-line therapy is increasingly important. Several therapeutic options are available, and different factors including not only patient- and disease-related characteristics, but also the first-line treatment received (i.e., type, timing of disease progression, observed outcome and reported toxicities) may drive this choice. Herein, we describe the current state of the art in the landscape of treatments after progression in mCRC. Based on a critical review of the literature, we built a patient-oriented therapeutic algorithm, aiming to guide clinicians in their daily decision-making.

A prospective, single-arm, multicenter trial of neoadjuvant chemotherapy with mFOLFOX6 plus panitumumab without radiotherapy for locally advanced rectal cancer

PURPOSE

The present study evaluated the safety and efficacy of neoadjuvant chemotherapy with modified 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus panitumumab in clinical stage III rectal cancer with KRAS wild-type.

METHODS

We conducted a prospective multicenter phase II trial. KRAS wild-type clinical stage III rectal cancer patients were enrolled. Patients received 6 cycles of mFOLFOX6 with 6 mg/kg panitumumab as neoadjuvant chemotherapy. The primary outcome was the response rate (RR) defined by RECIST. Lateral lymph node dissection (LLDN) was performed when patients had a locally advanced tumor < 9 cm from the anal margin.

RESULTS

A total of 50 patients were enrolled. Twelve (24.0%) experienced grade 3-4 adverse events during neoadjuvant chemotherapy. The RR was 88.0% (complete response 2.0%, partial response 86.0%), which met the primary outcome. All patients underwent laparoscopic surgery and achieved R0 resection. Seven patients underwent resection of other adjacent organs, and 43 underwent LLND. Twelve patients (24.0%) experienced grade 3-4 postoperative complications, and 4 (8.0%) had pathological complete response (pCR). Thirteen patients (26.0%) had lymph node metastasis. Forty-five patients (90.0%) received postoperative adjuvant chemotherapy. The 3-year relapse-free survival (RFS) and overall survival (OS) rates were 79.0% and 93.7%, respectively.

CONCLUSIONS

Neoadjuvant chemotherapy of mFOLFOX6 plus panitumumab without radiotherapy resulted in a low pCR rate but a high PR rate, low local recurrence rate, and good long-term outcome, suggesting that this treatment strategy may be a viable option for patients unable or unwilling to receive radiotherapy. The trial was registered with the UMIN Clinical Trials Registry, number 000006039.

Skin inflammatory response and efficacy of anti-epidermal growth factor receptor therapy in metastatic colorectal cancer (CUTACETUX)

Anti-epidermal growth factor receptor (EGFR) monoclonal antibody is a standard treatment of metastatic colorectal cancer (mCRC) and its most common adverse effect is a papulopustular acneiform rash. The aim of the CUTACETUX study was to characterize the skin inflammatory response associated with this rash and its relation to treatment efficacy. This prospective study included patients with mCRC treated with first-line chemotherapy plus cetuximab. Patients underwent skin biopsies before the initiation of cetuximab (D0) and before the third infusion (D28), one in a rash zone and one in an unaffected zone. Expression of Th17-related cytokines (IL-17A, IL-21, IL-22), antimicrobial peptides (S100A7 and BD-2), innate response-related cytokines (IL-1β, IL-6, TNF-α and OSM), T-reg-related cytokines (IL-10 and TGF-β), Th1-related cytokine (IFN-γ), Th2-related cytokine (IL-4), Thymic stromal lymphopoietin and keratinocyte-derived cytokines (IL-8, IL-23 and CCL20) were determined by RT-PCR. Twenty-seven patients were included. Levels of most of the cytokines increased at D28 in the rash zone compared to D0. No significant association was observed between variations of cytokines levels and treatment response in the rash zone and only the increase of IL-4 (p = .04) and IL-23 (p = .02) levels between D0 and D28 in the unaffected zone was significantly associated with treatment response. Increased levels of IL-8 (p = .02), BD-2 (p = .02), IL-1β (p = .004) and OSM (p = .02) in the rash zone were associated with longer progression-free survival. Expression of Th2-related and keratinocyte-derived cytokines in the skin was associated with anti-EGFR efficacy. If this inflammatory signature can explain the rash, the exact mechanism by which these cytokines are involved in anti-EGFR tumor response remains to be studied.

Nanobodies: The "Magic Bullets" in therapeutics, drug delivery and diagnostics

Antibodies represent a well-established class of clinical diagnostics for medical applications as well as essential research and biotechnological tools. Although both polyclonal and monoclonal antibodies are indispensable reagents in basic research and diagnostics but both of them have their limitations. Hence, there is urgent need to develop strategies aimed at production of alternative scaffolds and recombinant antibodies of smaller dimensions that could be easily produced, selected and manipulated. Unlike conventional antibodies, members of Camelidae and sharks produce antibodies composed only of heavy chains with small size, high solubility, thermal stability, refolding capacity and good tissue penetration in vivo. The discovery of these naturally occurring antibodies having only heavy-chain in Camelidae family and their further development into small recombinant nanobodies represents an attractive alternative in drug delivery, diagnostics and imaging. Nanobody derivatives are soluble, stable, versatile, have unique refolding capacities, reduced aggregation tendencies and high-target binding capabilities. They can be genetically customized to target enzymes, transmembrane proteins or molecular interactions. Their ability to recognize recessed antigenic sites has been attributed to their smaller size and the ability of the extended CDR3 loop to quickly penetrate into such epitopes. With the advent of molecular engineering and phage display technology, they can be of potential use in molecular imaging, drug delivery and therapeutics for several major diseases. In this review we present the recent advances in nanobodies for modulating immune functions, for targeting cancers, viruses, toxins and microbes as well as their utility as diagnostic and biosensor tools.

Precision Approaches in the Management of Colorectal Cancer: Current Evidence and Latest Advancements Towards Individualizing the Treatment

The genetic and molecular underpinnings of metastatic colorectal cancer have been studied for decades, and the applicability of these findings in clinical decision making continues to evolve. Advancements in translating molecular studies have provided a basis for tailoring chemotherapeutic regimens in metastatic colorectal cancer (mCRC) treatment, which have informed multiple practice guidelines. Various genetic and molecular pathways have been identified as clinically significant in the pathogenesis of metastatic colorectal cancer. These include rat sarcoma (RAS), epithelial growth factor receptor (EGFR), vascular endothelial growth factor VEGF, microsatellite instability, mismatch repair, and v-raf murine sarcoma viral oncogene homolog b1 (BRAF) with established clinical implications. RAS mutations and deficiencies in the mismatch repair pathway guide decisions regarding the administration of anti-EGFR-based therapies and immunotherapy, respectively. Furthermore, there are several emerging pathways and therapeutic modalities that have not entered mainstream use in mCRC treatment and are ripe for further investigation. The well-established data in the arena of targeted therapies provide evidence-based support for the use or avoidance of various therapeutic regimens in mCRC treatment, while the emerging pathways and platforms offer a glimpse into the future of transforming a precision approach into a personalized treatment.

Nimotuzumab Site-Specifically Labeled with 89Zr and 225Ac Using SpyTag/SpyCatcher for PET Imaging and Alpha Particle Radioimmunotherapy of Epidermal Growth Factor Receptor Positive Cancers

Simple Summary

Monoclonal antibodies (IgG) are excellent probes for targeting cell surface receptors for imaging and therapeutic applications. These theranostic agents are often developed by randomly conjugating radioisotopes/drugs/chelators to the primary amine of lysine or the sulfhydryl groups of cysteine on the antibody. Random conjugation often alters the properties of the antibody. We have site-specifically radiolabeled nimotuzumab an anti-epidermal growth factor receptor (EGFR) monoclonal antibody with 89Zr and 225Ac using SpyTag: ∆N-SpyCatcher for positron emission tomography (PET) imaging and alpha particle radiotherapy, and evaluated these agents in a model of EGFR-positive triple negative breast cancer (TNBC). Nimotuzumab-SpyTag-∆N-SpyCatcher constructs showed improved binding in vitro compared with randomly conjugated constructs. 89Zr-nimotuzumab-SpyTag-∆N-SpyCatcher specifically delineated EGFR-positive xenograft in vivo using microPET/CT imaging. Compared with control treatment groups, 225Ac-nimotuzumab-SpyTag-∆N-SpyCatcher more than doubled the survival of mice bearing EGFR-positive MDA-MB-231 TNBC xenograft. This work highlights a facile method to site-specifically radiolabel antibodies using SpyTag: ∆N-SpyCatcher.

Abstract

To develop imaging and therapeutic agents, antibodies are often conjugated randomly to a chelator/radioisotope or drug using a primary amine (NH₂) of lysine or sulfhydryl (SH) of cysteine. Random conjugation to NH₂ or SH groups can require extreme conditions and may affect target recognition/binding and must therefore be tested. In the present study, nimotuzumab was site-specifically labeled using ∆N-SpyCatcher/SpyTag with different chelators and radiometals. Nimotuzumab is a well-tolerated anti-EGFR antibody with low skin toxicities. First, ΔN-SpyCatcher was reduced using tris(2-carboxyethyl)phosphine (TCEP), which was followed by desferoxamine-maleimide (DFO-mal) conjugation to yield a reactive ΔN-SpyCatcher-DFO. The ΔN-SpyCatcher-DFO was reacted with nimotuzumab-SpyTag to obtain stable nimotuzumab-SpyTag-∆N-SpyCatcher-DFO. Radiolabeling was performed with ⁸⁹Zr, and the conjugate was used for the in vivo microPET imaging of EGFR-positive MDA-MB-468 xenografts. Similarly, ∆N-SpyCatcher was conjugated to an eighteen-membered macrocyclic chelator macropa-maleimide and used to radiolabel nimotuzumab-SpyTag with actinium-225 (²²⁵Ac) for in vivo radiotherapy studies. All constructs were characterized using biolayer interferometry, flow cytometry, radioligand binding assays, HPLC, and bioanalyzer. MicroPET/CT imaging showed a good tumor uptake of ⁸⁹Zr-nimotuzumab-SpyTag-∆N-SpyCatcher with 6.0 ± 0.6%IA/cc (n = 3) at 48 h post injection. The EC₅₀ of ²²⁵Ac-nimotuzumab-SpyTag-∆N-SpyCatcher and ²²⁵Ac-control-IgG-SpyTag-∆N-SpyCatcher against an EGFR-positive cell-line (MDA-MB-468) was 3.7 ± 3.3 Bq/mL (0.04 ± 0.03 nM) and 18.5 ± 4.4 Bq/mL (0.2 ± 0.04 nM), respectively. In mice bearing MDA-MB-468 EGFR-positive xenografts, ²²⁵Ac-nimotuzumab-SpyTag-∆N-SpyCatcher significantly (p = 0.0017) prolonged the survival of mice (64 days) compared to ²²⁵Ac-control IgG (28.5 days), nimotuzumab (28.5 days), or PBS-treated mice (30 days). The results showed that the conjugation and labeling using SpyTag/∆N-SpyCatcher to nimotuzumab did not significantly (p > 0.05) alter the receptor binding of nimotuzumab compared with a non-specific conjugation approach. ²²⁵Ac-nimotuzumab-SpyTag-∆N-SpyCatcher was effective in vitro and in an EGFR-positive triple negative breast cancer xenograft model.

Protocol of the EFFORT study: a prospective study of FOLFIRI plus aflibercept as second-line treatment after progression on FOLFOXIRI plus bevacizumab or during maintenance treatment in patients with unresectable/metastatic colorectal cancer

Background

FOLFOXIRI plus bevacizumab is used as a first-line therapy for patients with unresectable or metastatic colorectal cancer. However, there are no clear recommendations for second-line therapy after FOLFOXIRI plus bevacizumab combination. Here, we describe our planning for the EFFORT study to investigate whether FOLFIRI plus aflibercept has efficacy following FOLFOXIRI plus bevacizumab for mCRC.

Methods

EFFORT is an open-label, multicenter, single arm phase II study to evaluate whether a FOLFIRI plus aflibercept has efficacy following FOLFOXIRI plus bevacizumab for mCRC. Patients with unresectable or metastatic colorectal cancer who received FOLFOXIRI plus bevacizumab as a first-line therapy will receive aflibercept and FOLFIRI (aflibercept 4 mg/kg, irinotecan 150 mg/m² IV over 90 min, with levofolinate 200 mg/m² IV over 2 h, followed by fluorouracil 400 mg/m² bolus and fluorouracil 2400 mg/m² continuous infusion over 46 h) every 2 weeks on day 1 of each cycle. The primary endpoint is progression-free survival (PFS). To achieve 80% power to show a significant response benefit with a one-sided alpha level of 0.10, assuming a threshold progression-free survival of 3 months and an expected value of at least 5.4 months, we estimated that 32 patients are necessary. Secondary endpoints include overall survival, overall response rate, safety, and exploratory biomarker analysis for differentiating anti-VEGF drug in 2nd-line chemotherapy for unresectable or metastatic colorectal cancer.

Discussion

This is the first study to investigate whether FOLFIRI plus aflibercept has efficacy following FOLFOXIRI plus bevacizumab for unresectable or metastatic colorectal cancer. Switching to a different type of anti-VEGF drug in second-line therapy after FOLFOXIRI plus bevacizumab appears to be an attractive treatment strategy when considering survival benefit. It is expected that this phase II study will prove the efficacy of this strategy and that a biomarker for drug selection will be discovered.

Trial registration

Japan Registry of Clinical Trials jRCTs071190003. Registered April 18, 2019.

Efficacy and safety of panitumumab in a cohort of patients with metastatic colorectal cancer in France: PANI OUEST, a post-EMA-approval descriptive study with a geriatric oncology focus

BACKGROUND/AIMS

The Bretagne-Pays de la Loire cancer observatory, an oncology network created by the French Ministry of Health, is specifically dedicated to assess the use of new targeted anticancer therapies in routine practice. In line with the French National Cancer III program, our cancer network set up a real-life cohort, which is independent of the pharmaceutical industry, for patients with colorectal cancer to monitor patient safety and quality of care and promote pharmacovigilance.

MATERIALS AND METHODS

Panitumumab monotherapy was assessed in 243 patients with wild-type Kirsten rat sarcoma who were treated for metastatic colorectal cancer (mCRC) between July 2008 and December 2010 after prior chemotherapy using oxaliplatine and irinotecan. This was a post-European medicine agency marketing (EMA-M) study Results: This study shed light on the best practices, strategic adaptations, clinical results (treatment objective responses, 13%; progression free survival, 2.99 months [2.73-3.15]; and overall survival, 6.8 months [5.49-8.38]) as well as expected or unexpected (grade 3 or 4: 11.5%) secondary effects in the phase IV panitumumab treatment of mCRC.

CONCLUSION

Our results are similar to those by Amado whose phase III study led to obtaining EMA-M for panitumumab and tend to confirm the antitumor activity of this antiepidermal growth factor receptor antibody in the treatment of mCRC. In addition, our results opened avenues to further assessment of panitumumab use as monotherapy as well as its benefit-risk ratio while taking into account the patients' general and clinical characteristics. In 2012, the French National Authority for Health appended these data to the panitumumab transparency committee report.

Oncogenic allelic interaction in Xiphophorus highlights hybrid incompatibility

The Bateson–Dobzhansky–Muller (BDM) model describes negative epistatic interactions that occur between genes with a different evolutionary history to account for hybrid incompatibility and is a central theory explaining genetic mechanisms underlying speciation. Since the early 1900 s when the BDM model was forwarded examples of BDM incompatibility have been described in only a few nonvertebrate cases. This study reports the only vertebrate system, with clearly defined interacting loci, that supports the BDM model. In addition, this study also poses that tumorigenesis serves as a novel mechanism that accounts for postzygotic isolation.

Mixing genomes of different species by hybridization can disrupt species-specific genetic interactions that were adapted and fixed within each species population. Such disruption can predispose the hybrids to abnormalities and disease that decrease the overall fitness of the hybrids and is therefore named as hybrid incompatibility. Interspecies hybridization between southern platyfish and green swordtails leads to lethal melanocyte tumorigenesis. This occurs in hybrids with tumor incidence following progeny ratio that is consistent with two-locus interaction, suggesting melanoma development is a result of negative epistasis. Such observations make Xiphophorus one of the only two vertebrate hybrid incompatibility examples in which interacting genes have been identified. One of the two interacting loci has been characterized as a mutant epidermal growth factor receptor. However, the other locus has not been identified despite over five decades of active research. Here we report the localization of the melanoma regulatory locus to a single gene, rab3d, which shows all expected features of the long-sought oncogene interacting locus. Our findings provide insights into the role of egfr regulation in regard to cancer etiology. Finally, they provide a molecular explainable example of hybrid incompatibility.

Comparison of Various Phase I Combination Therapy Designs in Oncology for Evaluation of Early Tumor Shrinkage Using Simulations

There is still a lack of efficient designs for identifying the dose response in oncology combination therapies in early clinical trials. The concentration response relationship can be identified using the early tumor shrinkage time course, which has been shown to be a good early response marker of clinical efficacy. The performance of various designs using an exposure–tumor growth inhibition model was explored using simulations. Different combination effects of new drug M and cetuximab (reference therapy) were explored first assuming no effect of M on cetuximab (to investigate the type I error (α)), and subsequently assuming additivity or synergy between cetuximab and M. One‐arm, two‐arm, and four‐arm designs were evaluated. In the one‐arm design, 60 patients received cetuximab + M. In the two‐arm design, 30 patients received cetuximab and 30 received cetuximab + M. In the four‐arm design, in addition to cetuximab and cetuximab + M as standard doses, combination arms with lower doses of cetuximab were evaluated (15 patients/arm). Model‐based predictions or “simulated observations” of early tumor shrinkage at week 8 (ETS8) were compared between the different arms. With the same number of individuals, the one‐arm design showed better statistical power than other designs but led to strong inflation of α in case of misestimated reference for ETS8 value. The two‐arm design protected against this misestimation and, with the same total number of subjects, would provide higher statistical power than a four‐arm design. However, a four‐arm design would be helpful for exploring more doses of cetuximab in combination with M to better understand the interaction.

Graft-versus-cancereffect and innovative approaches in thetreatment of refractory solid tumors

Background/aim

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been used for the treatment of various refractory solid tumors during the last two decades. After the demonstration of graft-versus-leukemia (GvL) effect in a leukemic murine model following allo-HSCT from other strains of mice, graft-versus-tumor (GvT) effect in a solid tumor after allo-HSCT has also been reported in a murine model in 1984. Several trials have reported the presence of a GvT effect in patients with various refractory solid tumors, including renal, ovarian and colon cancers, as well as soft tissue sarcomas [1]. The growing data on haploidentical transplants also indicate GvT effect in some pediatric refractory solid tumors. Novel immunotherapy-based treatment modalities aim at inducing an allo-reactivity against the metastatic solid tumor via a GvT effect. Recipient derived immune effector cells (RDICs) in the antitumor reactivity following allo-HSCT have also been considered as an emerging therapy for advanced refractory solid tumors.

Conclusion

This review summarizes the background, rationale, and clinical results of immune-based strategies using GvT effect for the treatment of various metastatic and refractory solid tumors, as well as innovative approaches such as haploidentical HSCT, CAR-T cell therapies and tumor infiltrating lymphocytes (TIL).

BRAF Mutation in Colorectal Cancers: From Prognostic Marker to Targetable Mutation

Simple Summary

Colorectal cancer with a mutation in an oncogene BRAF has paid much attention, as it comprises a population with dismal prognosis since two decades ago. A series of research since then has successfully changed this malignancy to be treatable with specific treatment. Here we thoroughly overviewed the basic, translational and clinical studies on colorectal cancer with BRAF mutation from a physician’s viewpoint. Accumulating lines of evidence suggest that intervention of the trunk cellular growth signal transduction pathway, namely EGFR-RAS-RAF-MEK-ERK pathway, is a clue to controlling this disease. However, it is not so straightforward. Recent studies unveil the diverse and plastic nature of this signal transduction pathway. We will introduce our endeavor to conquer this condition, based on newly arriving datasets, and discuss how we could open the door to future development of CRC treatment.

Abstract

The Raf murine sarcoma viral oncogene homolog B (BRAF) mutation is detected in 8–12% of metastatic colorectal cancers (mCRCs) and is strongly correlated with poor prognosis. The recent success of the BEACON CRC study and the development of targeted therapy have led to the determination of BRAF-mutated mCRCs as an independent category. For nearly two decades, a growing body of evidence has established the significance of the BRAF mutation in the development of CRC. Herein, we overview both basic and clinical data relevant to BRAF-mutated CRC, mainly focusing on the development of treatment strategies. This review is organized into eight sections, including clinicopathological features, molecular features, prognosis, the predictive value of anti-epidermal growth factor receptor (EGFR) therapy, resistant mechanisms for BRAF-targeting treatment, the heterogeneity of the BRAF mutation, future perspectives, and conclusions. A characterization of the canonical mitogen-activated protein kinase (MAPK) pathway is essential for controlling this malignancy, and the optimal combination of multiple interventions for treatments remains a point of debate.

Phase 2 study of irinotecan plus cetuximab rechallenge as third-line treatment in KRAS wild-type metastatic colorectal cancer: JACCRO CC-08

BACKGROUND

Regorafenib or trifluridine/tipiracil as third-line treatment have limited efficacy in metastatic colorectal cancer (mCRC).

METHODS

This Phase 2 trial evaluated the efficacy and safety of irinotecan plus cetuximab rechallenge as third-line treatment in KRAS wild-type mCRC patients who achieved clinical benefit with first-line cetuximab-containing therapy. The primary endpoint was 3-month progression-free survival (PFS) rate. A sample size was calculated; 30 patients with a 3-month PFS rate of 45% deemed promising and 15% unacceptable. Patients with greater and less than the cut-off value of cetuximab-free intervals (CFIs) were classified into the long and short CFI groups, respectively, in subgroup analyses.

RESULTS

Among 34 eligible patients who received treatment at least once, 3-month PFS rate was 44.1% (95% confidence interval, 27.4-60.8%). The median PFS and overall survival (OS) were 2.4 and 8.2 months, respectively. The response and disease control rates were 2.9 and 55.9%, respectively. PFS and OS were significantly longer in the long- than in the short CFI group.

CONCLUSIONS

Irinotecan plus cetuximab rechallenge as third-line treatment for KRAS wild-type mCRC was safe and had promising activity, especially in those with a long CFI, warranting further investigation in a Phase 3 randomised trial.

CLINICAL TRIAL REGISTRATION

UMIN000010638.

Phase 2 study of cetuximab (Erbitux) in patients with progressive or recurrent endometrial cancer

INTRODUCTION

Overexpression of the epidermal growth factor receptor (EGFR) found in common subtypes of endometrial cancer has been associated with advanced stage disease and a poor prognosis. The purpose of this phase 2 study was to evaluate the efficacy and safety of cetuximab in patients with recurrent endometrial cancer.

METHODS

The study was an open-label phase 2 clinical trial conducted at two institutions. Patients with recurrent or progressive endometrial cancer of any histologic type with the exception of uterine sarcoma received cetuximab at an initial dose of 400 mg/m2 IV followed by weekly doses of 250 mg/m2. One cycle was considered 4 weeks of treatment. The primary efficacy endpoint was clinical benefit response, defined as a complete or partial response or prolonged stable disease (>8 weeks) by RECIST 1.0 criteria.

RESULTS

A total of 30 patients were enrolled with a median age of 64 years (range 42-83). Of the 20 evaluable patients, three (15%) had clinical benefit response (one complete response, two stable disease). The patient with a clinical benefit response received a total of 27 cycles and the two patients with stable disease were taken off the study due to progression after four and six cycles, respectively. Of the 10 inevaluable patients, nine received ≤1 cycle due to clinical deterioration and one had an anaphylactic reaction. One patient had a grade 3 rash which resolved after a delay in treatment. No dose reduction was reported.

CONCLUSIONS

In this cohort, single agent therapy with cetuximab was well tolerated and had a 15% clinical benefit response. Further studies are required to better identify patients who may respond to this treatment.

Phase Ib/II study of weekly topotecan and daily gefitinib in patients with platinum resistant ovarian, peritoneal, or fallopian tube cancer

INTRODUCTION

50-70% of epithelial ovarian cancers overexpress epidermal growth factor receptor, and its expression has been correlated with poor prognosis. We conducted a phase Ib/II trial to examine the efficacy, safety, and toxicity of gefitinib, a tyrosine kinase inhibitor, combined with topotecan in women with recurrent ovarian cancer with epidermal growth factor receptor positivity.

METHODS

Patients with measurable recurrent or persistent cancer after treatment with a platinum containing regimen with positive epidermal growth factor receptor expression, as determined by immunohistochemistry, were eligible for the study. Initial treatment was 250 mg/day gefitinib (oral) and 2.0 mg/m2 topotecan (intravenous) on days 1, 8, and 15, on a 28 day cycle. Dose escalations were planned for topotecan (dose levels 1-3: 2, 3, and 4 mg/m2) until the maximum tolerated dose was reached.

RESULTS

19 patients received a total of 61 cycles. Median age was 59.8 years (range 42-76 years). Histologic types in treated patients included 74% serous (n=14), 11% mixed (n=2), 11% transitional (n=2), and 5% clear cell (n=1). For phase Ib, three patients were treated at dose level 1, three at dose level 2, and three at dose level 3 for topotecan. The maximum tolerated dose was 4.0 mg/m2 (days 1, 8, and 15) for topotecan and 250 mg (daily) for gefitinib. Therefore, dose level 3 was used for phase II. Among the 19 patients, 63.2% (n=12) had progressive disease, 15.8% (n=3) had stable disease, 10.5% (n=2) had a partial response, and 10.5% (n=2) were not evaluable. The most serious adverse events of any grade attributed to the therapy were anemia (89.4%), neutropenia (68.4%), abdominal pain (84%), constipation (78.9%), and diarrhea (78.9%).

CONCLUSION

Although the drug combination was relatively well tolerated, this prospective phase Ib/II clinical trial did not show sufficient clinical activity of topotecan combined with gefitinib in patients with epidermal growth factor receptor positive recurrent ovarian, fallopian tube, or peritoneal cancers.

Cancer Immunotherapy Dosing: A Pharmacokinetic/Pharmacodynamic Perspective

Immune check-point inhibitors are drugs that are markedly different from other anticancer drugs because of their indirect mechanisms of antitumoral action and their apparently random effect in terms of efficacy and toxicity. This marked pharmacodynamics variability in patients calls for reconsidering to what extent approved dosing used in clinical practice are optimal or whether they should require efforts for customization in outlier patients. To better understand whether or not dosing could be an actionable item in oncology, in this review, preclinical and clinical development of immune checkpoint inhibitors are described, particularly from the angle of dose finding studies. Other issues in connection with dosing issues are developed, such as the flat dosing alternative, the putative role therapeutic drug monitoring could play, the rise of combinatorial strategies, and pharmaco-economic aspects.

Identification of a novel anti-EGFR nanobody by phage display and its distinct paratope and epitope via homology modeling and molecular docking

Since EGFR is an important and effective target for tumor therapy in the clinic. Several monoclonal antibodies and nanobodies were proved to target domain III of EGFR. Regarding the increased attention on nanobodies, the present study aimed to generate nanobodies specifically against domain III. After camel immunization, a gene repertoire of sdAb fragments with a diversity of 3×10⁹ clones was produced. Following the construction of two sdAb phage display libraries, the successful epitope binning was carried out to identify the nanobody with the designated epitope. Modelling of the identified nanobody and molecular docking studies illustrated the paratope and epitope. Docking analysis revealed that the paratope focused on CDR2 loop of the identified nanobody. The identified nanobody potently cover part of the epitope of Matuzumab and Nb 9G8, which indicated that it blocked EGFR by preventing dimerization of the receptors.

Comparative effectiveness of weekly versus every-2-weeks cetuximab in metastatic colorectal cancer in a US-insured population

Aim: To test the noninferiority of cetuximab administered every 2 weeks (Q2W) versus once weekly (Q1W) in treating metastatic colorectal cancer (mCRC) with regard to overall survival (OS). Patients: Patients receiving cetuximab plus chemotherapy for mCRC in a line-agnostic setting. Methods: This cohort study in IBM MarketScan followed patients from initiation of cetuximab for mCRC until the end of the data availability period, proxy-based death or loss of insurance coverage for >30 days. Results: The hazard ratio for OS was 0.94 (0.85-1.03), and the inferiority hypothesis was rejected at p < 0.001. No significant differences were noted in rates of safety events between Q2W and Q1W. Conclusion: Our real-world study confirmed the noninferiority of cetuximab administered Q2W versus Q1W for OS.

Colorectal liver metastases: Current management and future perspectives

The liver is the commonest site of metastatic disease for patients with colorectal cancer, with at least 25% developing colorectal liver metastases (CRLM) during the course of their illness. The management of CRLM has evolved into a complex field requiring input from experienced members of a multi-disciplinary team involving radiology (cross sectional, nuclear medicine and interventional), Oncology, Liver surgery, Colorectal surgery, and Histopathology. Patient management is based on assessment of sophisticated clinical, radiological and biomarker information. Despite incomplete evidence in this very heterogeneous patient group, maximising resection of CRLM using all available techniques remains a key objective and provides the best chance of long-term survival and cure. To this end, liver resection is maximised by the use of downsizing chemotherapy, optimisation of liver remnant by portal vein embolization, associating liver partition and portal vein ligation for staged hepatectomy, and combining resection with ablation, in the context of improvements in the functional assessment of the future remnant liver. Liver resection may safely be carried out laparoscopically or open, and synchronously with, or before, colorectal surgery in selected patients. For unresectable patients, treatment options including systemic chemotherapy, targeted biological agents, intra-arterial infusion or bead delivered chemotherapy, tumour ablation, stereotactic radiotherapy, and selective internal radiotherapy contribute to improve survival and may convert initially unresectable patients to operability. Currently evolving areas include biomarker characterisation of tumours, the development of novel systemic agents targeting specific oncogenic pathways, and the potential re-emergence of radical surgical options such as liver transplantation.

Arterial Embolization Using Microspheres for Hypervascular Liver Metastases Refractory to Standard Treatments: A Multicenter Prospective Clinical Trial

PURPOSE

To evaluate the clinical utility of bland arterial embolization using microspheres in patients with hypervascular liver metastases refractory to standard treatments.

MATERIALS AND METHODS

Primary endpoints of this prospective single-arm non-comparative study were objective response and disease control rates (ORR and DCR), based on the modified Response Evaluation Criteria in Solid Tumors at 4 weeks after embolization. Secondary endpoints were ORR according to primary tumor, overall survival, progression-free survival (PFS), and safety.

RESULTS

Twenty-five patients with a median age of 66 years (range, 40-95 years) were enrolled in this study. The median maximum diameter of liver metastasis was 3.7 cm (range, 2.0-15.2 cm). Primary lesions were colorectal cancer in 12 patients (48%, 12/25), other cancer in 7 (28%, 7/25), neuroendocrine tumor in 4 (16%, 4/25), and sarcoma in 2 (8%, 2/25). ORR and DCR were 52% (13/25) and 72% (18/25) in all patients, 42% (5/12) and 75% (9/12) in colorectal cancer patients, and 62% (8/13) and 69% (9/13) in other malignant tumor patients (p = 0.43, p > 0.99). Median survival time was 19 months in all patients, 19 months in colorectal cancer patients, and 8 months (p = 0.16) in other malignant tumor patients. Median PFS time was 4 months in all patients, 4 months in colorectal cancer patients, and 6 months (p = 0.0085) in other malignant tumor patients. There were no grade-3 or -4 adverse events.

CONCLUSION

Microsphere embolization appears to be an effective and safe treatment for hypervascular liver metastases refractory to standard treatments.

Hepatic Perfusion for Diffuse Metastatic Cancer to the Liver: Open and Percutaneous Techniques

The management of patients with diffuse liver metastases remains a significant clinical challenge. In many cancer patients, metastatic disease may be isolated to the liver or the liver may be the dominant site of progressive metastatic cancer. In this setting, progression of disease in the liver generally is the most significant cause of morbidity and mortality.

Carboplatin re-treatment in platinum-resistant epithelial ovarian cancer patients

PURPOSE

Treatment of multi-resistant epithelial ovarian cancer represents a clinical challenge with limited choices. Anti-angiogenic therapy has shown great potential in combination with frontline-therapy. Studies investigating heavily pre-treated patients are few. This study investigated the effect of re-treating patients with carboplatin combined with bevacizumab and cell-free DNA (cfDNA) as a potential predictor of outcome.

METHODS

This single-center study enrolled 73 multi-resistant ovarian cancer patients from 2008 to 2015. Patients were treated with a combination of bevacizumab (10 mg/kg) and carboplatin (AUC5) every 3 weeks. Baseline plasma samples were analyzed for cfDNA levels. Treatment response was evaluated based on the Response Evaluation Criteria in Solid Tumors (RECIST) criteria and CA125 blood values.

RESULTS

The response rate according to RECIST and/or CA125 was 57%. Median number of cycles was 6. The median progression-free survival and overall survival was 5.0 and 11.2 months, respectively. Eighteen patients developed allergic reactions to carboplatin. Patients were grouped into two cfDNA-groups according to median value. The cfDNA value was correlated to progression-free survival (PFS, p = 0.015), but not to overall survival (OS, p = 0.067) in the univariate analysis. In the multivariate analysis both PFS and OS were highly correlated to the levels of cfDNA (PFS, hazard ratio = 1.87, p = 0.012; OS, hazard ratio = 1.67, p = 0.037) with patients with high levels of cfDNA having poorest outcome.

CONCLUSION

Our results might provide guidance in cases with heavily pre-treated patients, where alternatives are limited. Carboplatin and bevacizumab treatment should be weighed against best supportive care, current non-platinum therapies and experimental treatment. cfDNA seems to offer prognostic insight.

Alternative Treatment Options in Patients with Colorectal Cancer Who Encounter Fluoropyrimidine-Induced Cardiotoxicity

5-Fluorouracil (5-FU) remains to be the backbone of chemotherapy regimens approved for treatment of colorectal cancer and other gastrointestinal cancers and breast cancer. The incidence of cardiotoxicity associated with 5-FU ranges from 1.5-18%. Previous studies also concluded that rechallenging a patient with previous 5-FU cardiotoxicity with either lower dose or another mode of administration could result in repeat of cardiac complication in up to 45% of patients. Nearly 13% of patients died upon re-exposure to 5-FU. Clinical manifestations of cardiac complications of fluoropyrimidines including angina, myocardial infarction, arrhythmias, hypotension, Tako-Tsubo syndrome, heart failure, cardiogenic shock, pericarditis, and even sudden death have been reported. Cardiotoxicity is unpredictable and no alternative chemotherapeutics have been defined so far. The author describes here treatment options for patients with metastatic colorectal cancer who have encountered fluoropyrimidine-induced cardiotoxicity, including switching to a different fluoropyrimidine, switching to a different schedule of intravenous 5-FU, or switching to a non-fluoropyrimidine-containing chemotherapy regimen if one exists. Switching to a non-fluoropyrimidine-containing chemotherapy regimen is usually the most feasible choice for patients with metastatic disease as data on adjuvant setting is usually a fluoropyrimidine or its combination with oxaliplatin at present.

Oral mucositis: the hidden side of cancer therapy

Inflammation response of epithelial mucosa to chemo- radiotherapy cytotoxic effects leads to mucositis, a painful side effect of antineoplastic treatments. About 40% of the patients treated with chemotherapy develop mucositis; this percentage rises to about 90% for head and neck cancer patients (HNC) treated with both chemo- and radiotherapy. 19% of the latter will be hospitalized and will experience a delay in antineoplastic treatment for high-grade mucositis management, resulting in a reduction of the quality of life, a worse prognosis and an increase in patient management costs. Currently, several interventions and prevention guidelines are available, but their effectiveness is uncertain. This review comprehensively describes mucositis, debating the impact of standard chemo-radiotherapy and targeted therapy on mucositis development and pointing out the limits and the benefits of current mucositis treatment strategies and assessment guidelines. Moreover, the review critically examines the feasibility of the existing biomarkers to predict patient risk of developing oral mucositis and their role in early diagnosis. Despite the expression levels of some proteins involved in the inflammation response, such as TNF-α or IL-1β, partially correlate with mucositis process, their presence does not exclude others mucositis-independent inflammation events. This strongly suggests the need to discover biomarkers that specifically feature mucositis process development. Non-coding RNAs might hold this potential.

Blood-based RAS mutation testing: concordance with tissue-based RAS testing and mutational changes on progression

Aim: To determine the concordance between plasma and tissue RAS mutation status in metastatic colorectal cancer patients to gauge whether blood-based testing is a viable alternative. We also evaluated the change in mutation status on progression. Materials/methods: RAS testing was performed on plasma from patients commencing first-line therapy (OncoBEAM™ RAS CEIVD kit). Results were then compared with formalin-fixed paraffin embedded tumor samples. Results: The overall percentage agreement (concordance) was 86.0% (86/100), which demonstrates that blood-based testing is an alternative to tissue-based testing. Reproducibility was 100% between three laboratories and 20% showed changes in their RAS mutational status on progression. Conclusion: These results show good concordance between tissue and plasma samples and suggest the need for longitudinal plasma testing during treatment to guide management decisions.

Efficacy and Safety of Regorafenib in Combination with Chemotherapy as Second-Line Treatment in Patients with Metastatic Colorectal Cancer: A Network Meta-Analysis and Systematic Literature Review

INTRODUCTION

Although various therapies are available for the treatment of metastatic colorectal cancer (mCRC), there is lack of head-to-head evidence. Recent studies have demonstrated the efficacy of chemotherapy in combination with different biological agents including regorafenib in second-line therapy in patients with mCRC. We conducted a network meta-analysis (NMA) to estimate the relative efficacy and safety of regorafenib in combination with chemotherapy compared to other biological agents with chemotherapy combinations.

METHODS

A literature search was conducted in PubMed, Embase, and Cochrane databases to identify all randomized controlled trials (RCTs) evaluating the efficacy and safety of bevacizumab, regorafenib, panitumumab, cetuximab, ramucirumab, conatumumab, ganitumab, and aflibercept in combination with chemotherapy against chemotherapy alone as second-line setting from inception to 7 February 2019 in patients with mCRC. The survival outcomes were analyzed by the frequentist statistical approach (R software, netmeta package) while the level of individual treatment arms was assessed using the Bayesian method (R software, gemtc package).

RESULTS

We identified 12 articles involving eight RCTs studies analyzing 6805 patients. The studies compared bevacizumab (3), regorafenib (1), panitumumab (2), cetuximab (3), ramucirumab (1), conatumumab (1), ganitumab (1), and aflibercept (1) against chemotherapy alone as comparator. The progression-free survival (PFS) revealed that regorafenib performed better than aflibercept (HR 0.9631, 95% CI 0.6785-1.367), ganitumab (HR 0.7228, 95% CI 0.3985-1.3109), panitumumab (HR 0.9653, 95% CI 0.6781-1.3742), and ramucirumab (HR 0.9206, 95% CI 0.6504-1.303). Regorafenib performed better than bevacizumab (OR 0.797, 95% CI 0.328-1.88) in terms of tumor response. Safety analysis showed that regorafenib performed better in reducing grade ≥ 3 adverse events (AE) than cetuximab and conatumumab, neutropenia than conatumumab, and fatigue than cetuximab.

CONCLUSIONS

Regorafenib combined with chemotherapy might be a potential alternative to conventional therapeutic options in second-line treatment of patients with metastatic colorectal cancer and could be considered as the best option for treating patients with KRAS and BRAF mutated mCRC. However future RCTs are needed to confirm these results.

Genomic Characterization of Cholangiocarcinoma in Primary Sclerosing Cholangitis Reveals Therapeutic Opportunities

BACKGROUND AND AIMS

Lifetime risk of biliary tract cancer (BTC) in primary sclerosing cholangitis (PSC) may exceed 20%, and BTC is currently the leading cause of death in patients with PSC. To open new avenues for management, we aimed to delineate clinically relevant genomic and pathological features of a large panel of PSC-associated BTC (PSC-BTC).

APPROACH AND RESULTS

We analyzed formalin-fixed, paraffin-embedded tumor tissue from 186 patients with PSC-BTC from 11 centers in eight countries with all anatomical locations included. We performed tumor DNA sequencing at 42 clinically relevant genetic loci to detect mutations, translocations, and copy number variations, along with histomorphological and immunohistochemical characterization. Regardless of the anatomical localization, PSC-BTC exhibited a uniform molecular and histological characteristic similar to extrahepatic cholangiocarcinoma. We detected a high frequency of genomic alterations typical of extrahepatic cholangiocarcinoma, such as TP53 (35.5%), KRAS (28.0%), CDKN2A (14.5%), and SMAD4 (11.3%), as well as potentially druggable mutations (e.g., HER2/ERBB2). We found a high frequency of nontypical/nonductal histomorphological subtypes (55.2%) and of the usually rare BTC precursor lesion, intraductal papillary neoplasia (18.3%).

CONCLUSIONS

Genomic alterations in PSC-BTC include a significant number of putative actionable therapeutic targets. Notably, PSC-BTC shows a distinct extrahepatic morpho-molecular phenotype, independent of the anatomical location of the tumor. These findings advance our understanding of PSC-associated cholangiocarcinogenesis and provide strong incentives for clinical trials to test genome-based personalized treatment strategies in PSC-BTC.

Summarising salient information on historical controls: A structured assessment of validity and comparability across studies

BACKGROUND

While placebo-controlled randomised controlled trials remain the standard way to evaluate drugs for efficacy, historical data are used extensively across the development cycle. This ranges from supplementing contemporary data to increase the power of trials to cross-trial comparisons in estimating comparative efficacy. In many cases, these approaches are performed without in-depth review of the context of data, which may lead to bias and incorrect conclusions.

METHODS

We discuss the original 'Pocock' criteria for the use of historical data and how the use of historical data has evolved over time. Based on these factors and personal experience, we created a series of questions that may be asked of historical data, prior to their use. Based on the answers to these questions, various statistical approaches are recommended. The strategy is illustrated with a case study in colorectal cancer.

RESULTS

A number of areas need to be considered with historical data, which we split into three categories: outcome measurement, study/patient characteristics (including setting and inclusion/exclusion criteria), and disease process/intervention effects. Each of these areas may introduce issues if not appropriately handled, while some may preclude the use of historical data entirely. We present a tool (in the form of a table) for highlighting any such issues. Application of the tool to a colorectal cancer data set demonstrates under what conditions historical data could be used and what the limitations of such an analysis would be.

CONCLUSION

Historical data can be a powerful tool to augment or compare with contemporary trial data, though caution is required. We present some of the issues that may be considered when involving historical data and what (if any) statistical approaches may account for differences between studies. We recommend that, where historical data are to be used in analyses, potential differences between studies are addressed explicitly.

Advances in epidermal growth factor receptor specific immunotherapy: lessons to be learned from armed antibodies

The epidermal growth factor receptor (EGFR) has been recognized as an important therapeutic target in oncology. It is commonly overexpressed in a variety of solid tumors and is critically involved in cell survival, proliferation, metastasis, and angiogenesis. This multi-dimensional role of EGFR in the progression and aggressiveness of cancer, has evolved from conventional to more targeted therapeutic approaches. With the advent of hybridoma technology and phage display techniques, the first anti-EGFR monoclonal antibodies (mAbs) (Cetuximab and Panitumumab) were developed. Due to major limitations including host immune reactions and poor tumor penetration, these antibodies were modified and used as guiding mechanisms for the specific delivery of readily available chemotherapeutic agents or plants/bacterial toxins, giving rise to antibody-drug conjugates (ADCs) and immunotoxins (ITs), respectively. Continued refinement of ITs led to deimmunization strategies based on depletion of B and T-cell epitopes or substitution of non-human toxins leading to a growing repertoire of human enzymes capable of inducing cell death. Similarly, the modification of classical ADCs has resulted in the first, fully recombinant versions. In this review, we discuss significant advancements in EGFR-targeting immunoconjugates, including ITs and recombinant photoactivable ADCs, which serve as a blueprint for further developments in the evolving domain of cancer immunotherapy.

Effectiveness of first-line cetuximab in wild-type RAS metastatic colorectal cancer according to tumour BRAF mutation status from the EREBUS cohort

AIMS

Poor efficacy has been reported for patients with BRAF mutations for metastatic colorectal cancer (mCRC).

METHODS

EREBUS is a French cohort study of wild-type (wt) KRAS unresectable mCRC patients initiating a first-line treatment with cetuximab from 2009 to 2010, followed for two years (five years for vital status). Molecular genetics platforms have provided additional RAS and BRAF mutation testing results. Progression-free survival (PFS) and overall survival (OS) were assessed according to tumour mutation (mt) status: RASmt/BRAFany, RASwt/BRAFmt and RASwt/BRAFwt. Multivariate Cox analyses were used to evaluate association between mutation status and death or progression.

RESULTS

A total of 389 patients were included in 65 centres and with a known tumour mutation status: 64 RASmt/BRAFany (21%), 33 RASwt/BRAFmt (13%) and 213 RASwt/BRAFwt (87%). Respective baseline characteristics were: median age 65, 64 and 63 years, male gender 63%, 64% and 69%, Eastern Cooperative Oncology Group performance status ≤ 1 75%, 76% and 79%, and liver-only metastases 39%, 33% and 40%. Median progression-free survival was 8.0 months [5.9-9.3] for patients with RASmt/BRAFany, 6.0 months [2.3-7.2] for patients with RASwt/BRAFmt, and 10.4 months [9.5-11.0] for patients with RASwt/BRAFwt. Respectively, median overall survival was 18.4 months [10.9-23.3], 9.7 months [6.9-16.6] and 29.3 months [26.3-36.1]. In multivariate analyses, progression (HR = 2.71 [1.79-4.10]) and death (HR = 2.79 [1.81-4.30]) were more likely for RASwt/BRAFmt vs RASwt/BRAFwt patients.

CONCLUSIONS

BRAF mutations were associated with markedly poorer outcomes in initially unresectable RASwt mCRC patients treated by cetuximab in first-line treatment.

Antibody-Based Immunotherapy: Alternative Approaches for the Treatment of Metastatic Melanoma

Melanoma is the least common form of skin cancer and is associated with the highest mortality. Where melanoma is mostly unresponsive to conventional therapies (e.g., chemotherapy), BRAF inhibitor treatment has shown improved therapeutic outcomes. Photodynamic therapy (PDT) relies on a light-activated compound to produce death-inducing amounts of reactive oxygen species (ROS). Their capacity to selectively accumulate in tumor cells has been confirmed in melanoma treatment with some encouraging results. However, this treatment approach has not reached clinical fruition for melanoma due to major limitations associated with the development of resistance and subsequent side effects. These adverse effects might be bypassed by immunotherapy in the form of antibody–drug conjugates (ADCs) relying on the ability of monoclonal antibodies (mAbs) to target specific tumor-associated antigens (TAAs) and to be used as carriers to specifically deliver cytotoxic warheads into corresponding tumor cells. Of late, the continued refinement of ADC therapeutic efficacy has given rise to photoimmunotherapy (PIT) (a light-sensitive compound conjugated to mAbs), which by virtue of requiring light activation only exerts its toxic effect on light-irradiated cells. As such, this review aims to highlight the potential clinical benefits of various armed antibody-based immunotherapies, including PDT, as alternative approaches for the treatment of metastatic melanoma.

Current Options for Third-line and Beyond Treatment of Metastatic Colorectal Cancer. Spanish TTD Group Expert Opinion

Colorectal cancer (CRC) is a public health problem: it is the third most common cancer in men (746,000 new cases/year) and the second in women (614,000 new cases/year), representing the second leading cause of death by cancer worldwide. The survival of patients with metastatic CRC (mCRC) has increased prominently in recent years, reaching a median of 25 to 30 months. A growing number of patients with mCRC are candidates to receive a treatment in third line or beyond, although the optimal drug regimen and sequence are still unknown. In this situation of refractoriness, there are several alternatives: (1) To administer sequentially the 2 oral drugs approved in this indication: trifluridine/tipiracil and regorafenib, which have shown a statistically significant benefit in progression-free survival and overall survival with a different toxicity profile. (2) To administer cetuximab or panitumumab in treatment-naive patients with RAS wild type, which is increasingly rare because these drugs are usually indicated in first- or second-line. (3) To reuse drugs already administered that were discontinued owing to toxicity or progression (oxaliplatin, irinotecan, fluoropyrimidine, antiangiogenics, anti-epidermal growth factor receptor [if RAS wild-type]). High-quality evidence is limited, but this strategy is often used in routine clinical practice in the absence of alternative therapies especially in patients with good performance status. (4) To use specific treatments for very selected populations, such as trastuzumab/lapatinib in mCRC human epidermal growth factor receptor 2-positive, immunotherapy in microsatellite instability, intrahepatic therapies in limited disease or primarily located in the liver, although the main recommendation is to include patients in clinical trials.

Hepatic arterial infusion of oxaliplatin plus systemic chemotherapy and targeted therapy for unresectable colorectal liver metastases

BACKGROUND

Hepatic arterial infusion (HAI) combined with systemic chemotherapy has shown promising results in patients with unresectable colorectal liver metastases (CRLM), even after failure to systemic therapy. Addition of systemic targeted therapies has been investigated with controversial results regarding tolerance, especially with HAI-floruxidine when combined with systemic bevacizumab. Our study aimed to analyse feasibility, safety and efficacy of HAI-oxaliplatin plus systemic chemotherapy and targeted therapies.

METHODS

Between 2005 and 2016, single-centre consecutive patients with unresectable CRLM who received at least one cycle of HAI-oxaliplatin plus systemic chemotherapy and targeted therapies (cetuximab/panitumumab or bevacizumab) were analysed.

RESULTS

A total of 89 patients (median age 55 years (range, 26-76 years) who previously received a median number of one systemic chemotherapy regimen (range, 0-5) including oxaliplatin in 78% of cases were included. Median number of HAI-oxaliplatin cycles was 9 (range, 1-28) combined with systemic chemotherapy and targeted therapies (LV5FU2 [63%], FOLFIRI [36%]) plus anti-EGFR (30%), or bevacizumab (70%). Grade 3/4 toxicities included neutropenia (40%), HAI-related abdominal pain (43%) and neurotoxicity (12%). The intent-to-treat objective response rate was 42%, and 45% had stable disease, allowing complete CRLM resection/ablation in 27% of patients. After a median follow-up of 72 months, median overall and progression-free survival was 20 and 9 months, respectively.

CONCLUSION

Addition of targeted therapy to systemic chemotherapy combined with HAI-oxaliplatin is feasible, safe and shows promising activity, even after systemic chemotherapy failure.

An Overview of Promising Biomarkers in Cancer Screening and Detection

Applications of biomarkers have been proved in oncology screening, diagnosis, predicting response to treatment as well as monitoring the progress of the disease. Considering the crucial role played by them during different disease stages, it is extremely important to evaluate, validate, and assess them to incorporate them into routine clinical care. In this review, the role of few most promising and successfully used biomarkers in cancer detection, i.e. PD-L1, E-Cadherin, TP53, Exosomes, cfDNA, EGFR, mTOR with regard to their structure, mode of action, and reports signifying their pathological significance, are addressed. Also, an overview of some successfully used biomarkers for cancer medicine has been presented. The study also summarizes biomarker-driven personalized cancer therapy i.e., approved targets and indications, as per the US FDA. The review also highlights the increasingly prominent role of biomarkers in drug development at all stages, with particular reference to clinical trials. The increasing utility of biomarkers in clinical trials is clearly evident from the trend shown, wherein ~55 percent of all oncology clinical trials in 2019 were seen to involve biomarkers, as opposed to ~ 15 percent in 2001, which clearly proves the essence and applicability of biomarkers for synergizing clinical information with tumor progression. Still, there are significant challenges in the implementation of these possibilities with strong evidence in cost-- effective manner.

Hyperphosphatemia Secondary to the Selective Fibroblast Growth Factor Receptor 1-3 Inhibitor Infigratinib (BGJ398) Is Associated with Antitumor Efficacy in Fibroblast Growth Factor Receptor 3-altered Advanced/Metastatic Urothelial Carcinoma

BACKGROUND

Infigratinib (BGJ398) is a potent, selective fibroblast growth factor receptor (FGFR) 1-3 inhibitor with significant activity in metastatic urothelial carcinoma (mUC) bearing FGFR3 alterations. It can cause hyperphosphatemia due to the "on-target" class effect of FGFR1 inhibition.

OBJECTIVE

To investigate the relationship between hyperphosphatemia and treatment response in patients with mUC.

INTERVENTION

Oral infigratinib 125 mg/d for 21 d every 28 d.

DESIGN, SETTING, AND PARTICIPANTS

Data from patients treated with infigratinib in a phase I trial with platinum-refractory mUC and activating FGFR3 alterations were retrospectively analyzed for clinical efficacy in relation to serum hyperphosphatemia. The relationship between plasma infigratinib concentration and phosphorous levels was also assessed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Clinical outcomes were compared in groups with/without hyperphosphatemia.

RESULTS AND LIMITATIONS

Of the 67 patients enrolled, 48 (71.6%) had hyperphosphatemia on one or more laboratory tests. Findings in patients with versus without hyperphosphatemia were the following: overall response rate 33.3% (95% confidence interval [CI] 20.4-48.4) versus 5.3% (95% CI 0.1-26.0); disease control rate 75.0% (95% CI 60.4-86.4) versus 36.8% (95% CI 16.3-61.6). This trend was maintained in a 1-mo landmark analysis. Pharmacokinetic/pharmacodynamic analysis showed that serum phosphorus levels and physiologic infigratinib concentrations were correlated positively. Key limitations include retrospective design, lack of comparator, and limited sample size.

CONCLUSIONS

This is the first published study to suggest that hyperphosphatemia caused by FGFR inhibitors, such as infigratinib, can be a surrogate biomarker for treatment response. These findings are consistent with other reported observations and will need to be validated further in a larger prospective trial.

PATIENT SUMMARY

Targeted therapy is a new paradigm in treating bladder cancer. In a study using infigratinib, a drug that targets mutations in a gene called fibroblast growth factor receptor 3 (FGFR3), we found that elevated levels of phosphorous were associated with greater clinical benefit. In the future, these data may help inform treatment strategies.

Molecular Targets for the Treatment of Metastatic Colorectal Cancer

Over the past years, colorectal cancer (CRC) was subtyped according to its molecular and genetic characteristics, allowing the development of therapeutic strategies, based on predictive biomarkers. Biomarkers such as microsatellite instability (MSI), RAS and BRAF mutations, HER2 amplification or NTRK fusions represent major tools for personalized therapeutic strategies. Moreover, the routine implementation of molecular predictive tests provides new perspectives and challenges for the therapeutic management of CRC patients, such as liquid biopsies and the reintroduction of anti-EGFR monoclonal antibodies. In this review, we summarize the current landscape of targeted therapies for metastatic CRC patients, with a focus on new developments for EGFR blockade and emerging biomarkers (MSI, HER2, NTRK).

Clinical Application of Targeted Deep Sequencing in Metastatic Colorectal Cancer Patients: Actionable Genomic Alteration in K-MASTER Project

Purpose

Next-generation sequencing (NGS) can facilitate precision medicine approaches in metastatic colorectal cancer (mCRC) patients. We investigated the molecular profiling of Korean mCRC patients under the K-MASTER project which was initiated in June 2017 as a nationwide precision medicine oncology clinical trial platform which used NGS assay to screen actionable mutations.

Materials and Methods

As of 22 January 2020, total of 994 mCRC patients were registered in K-MASTER project. Targeted sequencing was performed using three platforms which were composed of the K-MASTER cancer panel v1.1 and the SNUH FIRST Cancer Panel v3.01. If tumor tissue was not available, cell-free DNA was extracted and the targeted sequencing was performed by Axen Cancer Panel as a liquid biopsy.

Results

In 994 mCRC patients, we found 1,564 clinically meaningful pathogenic variants which mutated in 71 genes. Anti-EGFR therapy candidates were 467 patients (47.0%) and BRAF V600E mutation (n=47, 4.7%), deficient mismatch repair/microsatellite instability–high (n=15, 1.5%), HER2 amplifications (n=10, 1.0%) could be incorporated with recently approved drugs. The patients with high tumor mutation burden (n=101, 12.7%) and DNA damaging response and repair defect pathway alteration (n=42, 4.2%) could be enrolled clinical trials with immune checkpoint inhibitors. There were more colorectal cancer molecular alterations such as PIK3CA, KRAS G12C, atypical BRAF, and HER2 mutations and even rarer but actionable genes that approved or ongoing clinical trials in other solid tumors.

Conclusion

K-MASTER project provides an intriguing background to investigate new clinical trials with biomarkers and give therapeutic opportunity for mCRC patients.

Controversies in the treatment of RAS wild-type metastatic colorectal cancer

Objective

To provide guidance for the management of RAS wild-type (wt) metastatic colorectal cancer (mCRC) in daily practice.

Methods

Nominal group and Delphi techniques were used. A steering committee of seven experts analyzed the current management of RAS wt mCRC, through which they identified controversies, critically analyzed the available evidence, and formulated several guiding statements for clinicians. Subsequently, a group of 30 experts (the expert panel) was selected to test agreement with the statements, through two Delphi rounds. The following response categories were established in both rounds: 1 = totally agree, 2 = basically agree, 3 = basically disagree, 4 = totally disagree. Agreement was defined if ≥ 75% of answers were in categories 1 and 2 (consensus with the agreement) or 3 and 4 (consensus with the disagreement).

Results

Overall, 71 statements were proposed, which incorporated the following areas: (1) overarching principles; (2) tumor location; (3) triplets; (4) maintenance; (5) second-line and beyond treatments; (6) Rechallenge and liquid biopsy. After the two Delphi rounds, only six statements maintained a lack of clear consensus.

Conclusions

This document aims to describe the expert’s attitude when dealing with several common clinical questions regarding patients with RAS wt mCRC.

Electronic supplementary material

The online version of this article (10.1007/s12094-020-02475-8) contains supplementary material, which is available to authorized users.

Identifying optimal magnesium replenishment points based on risk of severe hypomagnesemia in colorectal cancer patients treated with cetuximab or panitumumab

PURPOSE

Cetuximab and panitumumab are monoclonal antibodies that target the epidermal growth factor receptor (EGFR). Treatment with cetuximab and panitumumab commonly causes hypomagnesemia, and optimal management of this adverse effect remains unclear. Here, we evaluated the optimal magnesium replacement points based on the risk of severe hypomagnesemia in colorectal cancer patients who received cetuximab or panitumumab.

METHODS

We retrospectively evaluated 184 patients who received cetuximab or panitumumab for colorectal cancer at Ogaki Municipal Hospital (Ogaki, Japan) between January 2010 and December 2019. Univariate analyses were conducted to evaluate the relationship between patient baseline characteristics and development of hypomagnesemia following cetuximab or panitumumab treatment. Variables that were significantly associated with hypomagnesemia in the univariate analyses as well as previously reported risk factors were entered into a multivariate logistic regression model.

RESULTS

The incidence of hypomagnesemia was associated with panitumumab treatment, pre-replenishment serum magnesium concentration, treatment duration, and treatment line. Severe hypomagnesemia post-cetuximab or panitumumab treatment was significantly associated with low baseline magnesium concentrations (< 1.8 mg/dL; odds ratio 18.100, 95% confidence interval 1.570-210.000; p = 0.020) and low serum magnesium concentrations during treatment (< 1.1 mg/dL; odds ratio 93.800, 95% confidence interval 3.510-2510.000; p = 0.007).

CONCLUSION

To minimize the risk of severe hypomagnesemia during anti-EGFR treatment, magnesium replenishment should be initiated in patients with pre-replenishment concentrations of < 1.8 mg/dL, preferably before reaching intra-treatment concentrations of < 1.1 mg/dL.

Past, Present, and Future of Anticancer Nanomedicine

This review aims to summarize the methods that have been used till today, highlight methods that are currently being developed, and predict the future roadmap for anticancer therapy. In the beginning of this review, established approaches for anticancer therapy, such as conventional chemotherapy, hormonal therapy, monoclonal antibodies, and tyrosine kinase inhibitors are summarized. To counteract the side effects of conventional chemotherapy and to increase limited anticancer efficacy, nanodrug- and stem cell-based therapies have been introduced. However, current level of understanding and strategies of nanodrug and stem cell-based therapies have limitations that make them inadequate for clinical application. Subsequently, this manuscript reviews methods with fewer side effects compared to those of the methods mentioned above which are currently being investigated and are already being applied in the clinic. The newer strategies that are already being clinically applied include cancer immunotherapy, especially T cell-mediated therapy and immune checkpoint inhibitors, and strategies that are gaining attention include the manipulation of the tumor microenvironment or the activation of dendritic cells. Tumor-associated macrophage repolarization is another potential strategy for cancer immunotherapy, a method which activates macrophages to immunologically attack malignant cells. At the end of this review, we discuss combination therapies, which are the future of cancer treatment. Nanoparticle-based anticancer immunotherapies seem to be effective, in that they effectively use nanodrugs to elicit a greater immune response. The combination of these therapies with others, such as photothermal or tumor vaccine therapy, can result in a greater anticancer effect. Thus, the future of anticancer therapy aims to increase the effectiveness of therapy using various therapies in a synergistic combination rather than individually.

Colorectal cancer residual disease at maximal response to EGFR blockade displays a druggable Paneth cell-like phenotype

Blockade of epidermal growth factor receptor (EGFR) causes tumor regression in some patients with metastatic colorectal cancer (mCRC). However, residual disease reservoirs typically remain even after maximal response to therapy, leading to relapse. Using patient-derived xenografts (PDXs), we observed that mCRC cells surviving EGFR inhibition exhibited gene expression patterns similar to those of a quiescent subpopulation of normal intestinal secretory precursors with Paneth cell characteristics. Compared with untreated tumors, these pseudodifferentiated tumor remnants had reduced expression of genes encoding EGFR-activating ligands, enhanced activity of human epidermal growth factor receptor 2 (HER2) and HER3, and persistent signaling along the phosphatidylinositol 3-kinase (PI3K) pathway. Clinically, properties of residual disease cells from the PDX models were detected in lingering tumors of responsive patients and in tumors of individuals who had experienced early recurrence. Mechanistically, residual tumor reprogramming after EGFR neutralization was mediated by inactivation of Yes-associated protein (YAP), a master regulator of intestinal epithelium recovery from injury. In preclinical trials, Pan-HER antibodies minimized residual disease, blunted PI3K signaling, and induced long-term tumor control after treatment discontinuation. We found that tolerance to EGFR inhibition is characterized by inactivation of an intrinsic lineage program that drives both regenerative signaling during intestinal repair and EGFR-dependent tumorigenesis. Thus, our results shed light on CRC lineage plasticity as an adaptive escape mechanism from EGFR-targeted therapy and suggest opportunities to preemptively target residual disease.

Tumor organoids to study gastroesophageal cancer: a primer

Gastroesophageal cancers are leading causes of cancer death. Our attempts at adopting molecularly based treatment approaches have been slow and ineffective even though we begin to identify specific targetable gene mutations and pathways. It is clear that we should no longer treat all gastroesophageal cancers as a homogeneous disease, which is what we do when we use non-specific chemotherapy. However, we currently cannot monitor successful gene/pathway targeting, nor understand how/when tumors develop resistance, nor predict which patients will derive maximal benefit. To improve outcomes, we must precisely detail the heterogeneity of these tumors to then individualize cancer therapy as well as develop novel avenues to study and predict treatment effects in individual patients. To this end, patient-derived organoids, in which tumor cells from individual patients are grown in a Petri dish, are a new versatile system that allows for timely expandability, detailed molecular characterization, and genetic manipulation with the promise of enabling predictive assessment of treatment response. In this review, we will explore the development and basic techniques for organoid generation, and discuss the current and potential future applications of this exciting technology to study the basic science of carcinogenesis and to predict/guide cancer patient care in the clinics.

The Latest Battles Between EGFR Monoclonal Antibodies and Resistant Tumor Cells

Epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor involved in homeostatic regulation of normal cells and carcinogenesis of epithelial malignancies. With rapid development of the precision medicine era, a series of new therapies targeting EGFR are underway. Four EGFR monoclonal antibody drugs (cetuximab, panitumumab, nimotuzumab, and necitumumab) are already on the market, and a dozen other EGFR monoclonal antibodies are in clinical trials. Here, we comprehensively review the newly identified biological properties and anti-tumor mechanisms of EGFR monoclonal antibodies. We summarize recently completed and ongoing clinical trials of the classic and new EGFR monoclonal antibodies. More importantly, according to our new standard, we re-classify the complex evolving tumor cell resistance mechanisms, including those involving exosomes, non-coding RNA and the tumor microenvironment, against EGFR monoclonal antibodies. Finally, we analyzed the limitations of EGFR monoclonal antibody therapy, and discussed the current strategies overcoming EGFR related drug resistance. This review will help us better understand the latest battles between EGFR monoclonal antibodies and resistant tumor cells, and the future directions to develop anti-tumor EGFR monoclonal antibodies with durable effects.

Therapeutic paradigm of dual targeting VEGF and PDGF for effectively treating FGF-2 off-target tumors

FGF-2 displays multifarious functions in regulation of angiogenesis and vascular remodeling. However, effective drugs for treating FGF-2⁺ tumors are unavailable. Here we show that FGF-2 modulates tumor vessels by recruiting NG2⁺ pricytes onto tumor microvessels through a PDGFRβ-dependent mechanism. FGF-2⁺ tumors are intrinsically resistant to clinically available drugs targeting VEGF and PDGF. Surprisingly, dual targeting the VEGF and PDGF signaling produces a superior antitumor effect in FGF-2⁺ breast cancer and fibrosarcoma models. Mechanistically, inhibition of PDGFRβ ablates FGF-2-recruited perivascular coverage, exposing anti-VEGF agents to inhibit vascular sprouting. These findings show that the off-target FGF-2 is a resistant biomarker for anti-VEGF and anti-PDGF monotherapy, but a highly beneficial marker for combination therapy. Our data shed light on mechanistic interactions between various angiogenic and remodeling factors in tumor neovascularization. Optimization of antiangiogenic drugs with different principles could produce therapeutic benefits for treating their resistant off-target cancers.

Anti-VEGF therapy has many limitations that might be resolved by using combination treatment approaches. Here, the authors demonstrate that the dual-targeting of VEGF and PDGF is required for targeting resistant FGF2+ tumors which depend on the recruitment of pericytes on tumor microvessels.