Epidermal Growth Factor Receptor Inhibition in Epidermal Growth Factor Receptor-Amplified Gastroesophageal Cancer: Retrospective Global Experience

PURPOSE

Subset analyses from phase III evaluation of epidermal growth factor receptor inhibition (EGFRi) suggest improved outcomes in patients with EGFR-amplified gastroesophageal adenocarcinoma (GEA), but large-scale analyses are lacking. This multi-institutional analysis sought to determine the role of EGFRi in the largest cohort of patients with EGFR-amplified GEA to date.

PATIENTS AND METHODS

A total of 60 patients from 15 tertiary cancer centers in six countries met the inclusion criteria. These criteria required histologically confirmed GEA in the metastatic or unresectable setting with EGFR amplification identified by using a Clinical Laboratory Improvement Amendments-approved assay, and who received on- or off-protocol EGFRi. Testing could be by tissue next-generation sequencing, plasma circulating tumor DNA next-generation sequencing, and/or fluorescence in situ hybridization performed by a Clinical Laboratory Improvement Amendments approved laboratory. Treatment patterns and outcomes analysis was also performed using a deidentified clinicogenomic database (CGDB).

RESULTS

Sixty patients with EGFR-amplified GEA received EGFRi, including 31 of 60 patients (52%) with concurrent chemotherapy. Across treatment lines, patients achieved a 43% objective response rate with a median progression-free survival of 4.6 months (95% CI, 3.5 to 6.4). Patients receiving EGFRi in first-, second-, and third-line therapy achieved a median overall survival of 20.6 months (95% CI, 13.5 to not reached [NR]), 9 months (95% CI, 7.9 to NR), and 8.4 months (7.6 to NR), respectively. This survival far exceeded the 11.2-month (95% CI, 8.7 to 14.2) median overall survival from first-line initiation of non-EGFRi therapy in patients with EGFR-amplified GEA in the CGDB. Despite this benefit, analysis of the CGDB (January 2011-December 2020) suggests that only 5% of patients with EGFR-amplified GEA received EGFRi.

CONCLUSION

Patients with EGFR-amplified GEA derive significant benefit from EGFRi. Further prospective investigation of EGFRi in a well-selected patient population is ongoing in an upcoming trial of amivantamab in EGFR and/or MET amplified GEA.

CA209-8YD: A phase I/II trial of rucaparib in combination with ramucirumab with or without nivolumab in previously treated advanced gastroesophageal adenocarcinoma (GEA) (RiME)

TPS377

Background: GEA is one of the leading causes of cancer-related deaths worldwide and in the US. In chemo refractory GEA, therapeutic options are limited with modest efficacy. About 35% of GC have DNA damage response (DDR) gene alterations and PARP inhibitors have shown to induce synthetic lethality and reduce tumor burden in in vitro and in vivo models of GEA. DDR deficient tumors have increased tumor mutational load, tumor infiltrating lymphocytes, and increased chemokines and PD-L1 expression in the tumor microenvironment. PARP inhibitors like rucaparib enhance antigen presentation, induce pro-inflammatory cytokines, influence PD-1/PD-L1 expression, and modulate T- and B- cell activity. Furthermore, results from multiple GEA early phase trials have supported the immune modulatory impact of VEGF targeted agents like ramucirumab. We hypothesize that modulation of the tumor microenvironment via PARP and VEGF inhibition will enhance anti-tumor immunity and lead to clinical synergy when combined with immune checkpoint inhibitors like nivolumab in this population. Methods: A safety lead in phase of 6-9 patients will be followed by an open label, two parallel cohorts phase II study. A total of 52 patients (26 in each cohort) will be enrolled. A starting rucaparib dose of 600 mg BID in combination with the standard doses of ramucirumab and flat doses of nivolumab will be used for the safety lead in. Rucaparib dose will be lowered for phase II if > 1/6 patients experienced DLTs. Participants enrolled to cohort A will receive rucaparib at the recommended phase II dose (RP2D) PO twice daily + ramucirumab 8mg/kg IV q2w + nivolumab 480mg IV q4w (28-day cycles). Participants in cohort B will receive rucaparib at RP2D PO twice daily + ramucirumab 8mg/kg IV q2w (28-day cycles). Assessment of tumor response using modified RECIST v1.1 will be done every 2 cycles. 50% of Pts who will be enrolled in each of the 2 cohorts must have a deleterious tumor gene alteration in at least 1 gene in a screening 17-gene homologous recombination deficient (HRD) panel. Eligible Pts received ≥1 line of therapy, ECOG PS 0-1, adequate organ function, no prior PARP inhibitors, and have mismatch repair (MMR) proficient tumors with measurable disease. Primary objectives are to determine the RP2D and overall response rate (ORR) in phase I and II respectively. Secondary objectives include safety, overall benefit rate (OBR), median PFS, OS, and ORR in HRD positive and negative cohorts. Enrollment to the RiME trial is currently ongoing. The study is funded by research grants from Bristol Myers Squibb and Clovis. Clinical trial information: NCT03995017.

Safety and efficacy of combining genotype-guided irinotecan (Iri) with 5FU, leucovorin (LV), oxaliplatin (Ox), and docetaxel (Tax) (gFOLFOXIRITAX): The I-FLOAT phase 1 dose-escalation study for advanced upper GI cancers

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Background: 5FU, Ox, Iri, and Tax are each active in upper GI cancers. Triplet cytotoxic therapies (txs) improved survival compared to doublets/singlets. However, combination of all 4 agents (FOLFOXIRITAX) has not been studied. UGT1A1 polymorphisms reduce UGT enzymatic activity predisposing to Iri toxicity. We sought to determine the maximum tolerated dose (MTD) in the 1st month of tx among each of the low (L), intermediate (I) and high (H) risk UGT1A1 genotype (UGT) groups. Methods: Previously untx’d advanced upper GI cancer patients (pts) with ECOG PS 0/1 received gFOLFOXIRITAX (+ trastuzumab if HER2+) with pegfilgrastim. 5FU 2400mg/m2 over 46 hrs, LV 400mg/m2, Ox 85mg/m2, and Tax 25mg/m2 were given IV Q14 days. UGT-L, I, and H risk groups received starting Iri dose levels (DL1) of 120, 105 and 45mg/m2, respectively; Iri doses were escalated in each UGT group by 15mg/m2 increments and Tax to DL2 of 37.5mg/m2 using a I3+3 novel design (Liu & Ji. J Biopharm Stat 2020). Other endpoints included overall safety (thru up to 8 cycles before maintenance 5FU +/- Iri/tras), ORR (RECIST1.1), & ctDNA response (> 50% decrease in highest MAF) by G360 (Guardant Health). Results: From 6/30/2020-8/6/2021 20 pts (8F, 12M) enrolled: median age 50 (range 21-76); 8 ECOG PS 1, UGT-L:I:H with 3:14:3 pts; 10 esophageal, 6 gastric, 2 pancreatic, 1 unknown GI primary and 1 bile duct cancer; 2 pts HER2+; 18 metastatic, 2 locally advanced unresectable. The median (range) of albumin and neutrophil-to-lymphocyte ratio (NLR) were 3.9 mg/dL (3.3-4.6) and 4.28 (1.89-27.6), respectively; 80% (16/20) of pts had a NLR > 2.88, a poor prognostic marker. Dose limiting toxicities (DLTs) were seen in 4 pts: one G3 diarrhea (UGT-H, DL1/DL1 Iri/Tax), two G3 sepsis not neutropenic (one UGT-I, DL2/DL2 Iri/Tax; and one UGT-I, DL3/DL1 Iri/Tax) and one G3 fatigue (UGT-I DL2/DL2 Iri/Tax). MTD has not been reached in any UGT TAX DL1 cohorts to date; currently enrolling UGT-H Iri/Tax DL1/DL1, UGT-I DL4/DL1, & UGT-L DL3/DL1. Any Gr tx related toxicities in ³ 10% pts thru up to 8 cycles: nausea (70%), fatigue (70%, 5% G3), diarrhea (65%, 5% G3), anorexia (50%), peripheral neuropathy (30%, 5% G3), anemia (30%), thrombocytopenia (25%), elevated LFTs (25%), hyponatremia (25%), vomiting (20%), mucositis (20%, 5% G3), hyperglycemia (20%), edema (15%), alopecia (15%), hypocalcemia (15%) and dysgeusia (10%). Of evaluable pts across all cohorts, PR/CR was seen in 13/16 (81%) patients, with 2 (12.5%) SD and 1 (6.25%) PD for a disease control rate of 94%. Of evaluable pts, best ctDNA response was seen in 12/13 (92%). Conclusions: gFOLFOXIRITAX demonstrated tolerability at initial dose levels of Iri/Tax, with dose escalation continuing. Efficacy is promising and could be an aggressive approach in upper GI cancers having high relapse risk in curative-intent settings. Clinical trial information: NCT04361708.

Spatial and Temporal Heterogeneity of PD-L1 Expression and Tumor Mutational Burden in Gastroesophageal Adenocarcinoma at Baseline Diagnosis and after Chemotherapy

PURPOSE

Intrapatient heterogeneity of programmed death ligand 1 (PD-L1) expression and tumor mutational burden (TMB) in gastroesophageal adenocarcinoma (GEA) could influence their roles as predictive biomarkers for response to immune checkpoint inhibitors (ICI). In this retrospective analysis, we evaluated the spatiotemporal heterogeneity and prognostic relevance of PD-L1 expression and TMB in GEA.

EXPERIMENTAL DESIGN

A cohort of 211 patients with stage II-IV GEA was retrospectively reviewed for a total of 407 tumor samples with PD-L1 expression data and 319 tumor samples with TMB data. PD-L1 status was defined as positive if combined positive score (CPS) ≥1 using the 22C3 pharmDx assay. TMB levels were categorized as low, intermediate, or high (≤5, 5-15, or >15 mutations/Mb), or using a single threshold (<10 or ≥10 mutation/Mb), determined by next-generation sequencing using a targeted gene panel.

RESULTS

Of 407 tumors, 56% were PD-L1 negative and 44% PD-L1 positive. Of 319 tumors, 50% were TMB-low, 45% TMB-intermediate, and 5% TMB-high; 86% had <10 and 14% ≥10 mutations/Mb. TMB level was significantly associated with MSI-status. PD-L1 expression and TMB exhibited marked spatial heterogeneity between baseline primary and metastatic tumors (61% and 69% concordance), and temporal heterogeneity between tumors before and after chemotherapy (57%-63% and 73%-75% concordance). PD-L1 expression and TMB were not significantly associated with overall survival.

CONCLUSIONS

PD-L1 expression and TMB exhibit marked spatial and temporal heterogeneity in GEA. This heterogeneity should be considered when obtaining tumor samples for molecular testing and when deciding whether ICI therapy is appropriate.See related commentary by Klempner et al., p. 6401.

Personalized Antibodies for Gastroesophageal Adenocarcinoma (PANGEA): A Phase II Study Evaluating an Individualized Treatment Strategy for Metastatic Disease

The one-year and median overall survival (mOS) rates of advanced gastroesophageal adenocarcinomas (GEA) are ∼50% and <12 months, respectively. Baseline spatial and temporal molecular heterogeneity of targetable alterations may be a cause of failure of targeted/immunooncologic therapies. This heterogeneity, coupled with infrequent incidence of some biomarkers, has resulted in stalled therapeutic progress. We hypothesized that a personalized treatment strategy, applied at first diagnosis then serially over up to three treatment lines using monoclonal antibodies combined with optimally sequenced chemotherapy, could contend with these hurdles. This was tested using a novel clinical expansion-platform type II design with a survival primary endpoint. Of 68 patients by intention-to-treat, the one-year survival rate was 66% and mOS was 15.7 months, meeting the primary efficacy endpoint (one-sided P = 0.0024). First-line response rate (74%), disease control rate (99%), and median progression-free survival (8.2 months) were superior to historical controls. The PANGEA strategy led to improved outcomes warranting a larger randomized study. SIGNIFICANCE: This study highlights excellent outcomes achieved by individually optimizing chemotherapy, biomarker profiling, and matching of targeted therapies at baseline and over time for GEA. Testing a predefined treatment strategy resulted in improved outcomes versus historical controls. Therapeutic resistance observed in correlative analyses suggests that dual targeted inhibition may be beneficial.This article is highlighted in the In This Issue feature, p. 211.

Influence of the Al content on the in vitro bioactivity and biocompatibility of PVD Ti1−xAlxN coatings for orthopaedic applications

The biomedical applications of titanium aluminium nitride (Ti_1−xAlxN) coatings strongly depend on roughness, wettability and aluminium content.

Curcumin promotes autophagic survival of a subset of colon cancer stem cells, which are ablated by DCLK1-siRNA

Curcumin is known to induce apoptosis of cancer cells by different mechanisms, but its effects on cancer stem cells (CSC) have been less investigated. Here, we report that curcumin promotes the survival of DCLK1-positive colon CSCs, potentially confounding application of its anticancer properties. At optimal concentrations, curcumin greatly reduced expression levels of stem cell markers (DCLK1/CD44/ALDHA1/Lgr5/Nanog) in three-dimensional spheroid cultures and tumor xenografts derived from colon cancer cells. However, curcumin unexpectedly induced proliferation and autophagic survival of a subset of DCLK1-positive CSCs. Spheroid cultures were disintegrated by curcumin in vitro but regrew within 30 to 40 days of treatment, suggesting a survival benefit from autophagy, permitting long-term persistence of colorectal cancer. Notably, RNA interference-mediated silencing of DCLK1 triggered apoptotic cell death of colon cancer cells in vitro and in vivo, and abolished colorectal cancer survival in response to curcumin; combination of DCLK1-siRNA and curcumin dramatically reversed CSC phenotype, contributing to attenuation of the growth of spheroid cultures and tumor xenografts. Taken together, our findings confirm a role of DCLK1 in colon CSCs and highlight DCLK1 as a target to enhance antitumor properties of curcumin.

Freeze-fracture electron microscopy of lipid membranes on colloidal polyelectrolyte multilayer coated supports

Lipid membranes were assembled on polyelectrolyte (PE)-coated colloidal particles. The assembly was studied by means of confocal microscopy, flow cytometry, scanning force microscopy, and freeze-fracture electron microscopy. A homogeneous lipid coverage was established within the limits of optical resolution. Flow cytometry showed that the lipid coverage was uniform. Freeze-fracture electron microscopy revealed that the lipid was adsorbed as a bilayer, which closely followed the surface profile of the polyelectrolyte support. Additional adsorption of polyelectrolyte layers on top of the lipid bilayer introduced inhomogeneities as evident from jumps in the fracture plane. Characteristic lipid multilayers have not been seen with freeze-fracture electron microscopy.

Permeation of macromolecules into polyelectrolyte microcapsules

Polyelectrolyte microcapsules (PEMCs) have been prepared by coating red blood cells with the polyelectrolytes poly(styrenesulfonate), poly(allylamine hydrochloride), and dextran sulfate applying the layer-by-layer technique with subsequent dissolution of the core. The capsule permeability for human serum albumin (HSA) was studied as a function of the ionic strength and pH by means of confocal microscopy. PEMCs produced with dextran sulfate and poly(allylamine hydrochloride) show a significant increase in permeability for HSA at salt concentrations over 1 mM. For PEMCs prepared with poly(styrenesulfonate) and poly(allylamine hydrochloride) the limiting salt concentration is 5 mM. No pH dependence for permeation was observed. A correlation between the permeation and adsorption of HSA on the PEMC walls was investigated. Finally, a mechanism for the permeability, combining electrostatic interactions, and the presence of pores in the polymer layers is presented confirmed by the considerable increase of permeation of charged molecules in the presence of salt and the permeation of neutral molecules regardless of the ionic strength.

Synthesis, structure, and antitumor activity of a novel tetranuclear titanium complex

The coordination complex cyclo-tetrakis[bis(1-phenyl-3-methyl-4-benzoylpyrazolon-5-ato++ +)mu-o xotitanium(IV)] has been synthesized and characterized with IR and NMR spectroscopies and X-ray diffraction. The core of this species consists of an eight-membered Ti-mu-oxo ring with alternate short-long Ti-O bond lengths. Besides these two O ligands, each metal is bound octahedrally to four O atoms from two chelating 1-phenyl-3-methyl-4-benzoylpyrazolon-5-ato anions. Several sets of Ti-O bond lengths are present: the shortest are the two Ti-O(oxo) (which are cis to each other), the longest are the two Ti-O(acyl) (cis to each other), and the two Ti-O(pyrazolonato) (trans to each other) are intermediate. The beta-diketonate ligand asymmetry, a feature considered essential in other antitumor Ti compounds, induces the short-long Ti-O(oxo) sequence of bond lengths. The antitumor activity of this compound, encapsulated in a dipalmitoylphosphatidylcholine liposome, has been studied in vitro using TA-3 (mouse mammary adenocarcinoma), HEP-2 (human epithelial larynx carcinoma), and VERO (African green monkey kidney) cell lines and in vivo in CF-1 and AJ female mice ip inoculated with TA-3. In vitro cytotoxicity is greater for TA-3 than for HEP-2 and null for VERO cell lines. In vivo results show a marked increase in survival time (T/C = 293% for AJ and 208% for CF-1), whereas tumor weight decrease was observed for CF-1-treated mice. These results suggest the Ti complex-liposome system may be promising as an antitumor drug.

Microencapsulation by means of step-wise adsorption of polyelectrolytes

Step-wise adsorption of polyelectrolytes is used for the fabrication of micro- and nanocapsules with determined size, capsule wall composition and thickness. The capsule walls made of polyelectrolyte multilayers exclude high molecular weight compounds. Assembling of lipid layers onto these polyelectrolyte capsules prevents the permeation of small dyes. Encapsulation of magnetite nanoparticles is demonstrated and the features of these novel capsules are discussed.

Microencapsulation of Organic Solvents in Polyelectrolyte Multilayer Micrometer-Sized Shells

Hollow-shell micrometer-sized particles were fabricated in aqueous media by stepwise deposition of oppositely charged polyelectrolytes onto melamine latex particles and biological cells with a dissolution of the core afterward. It is demonstrated that these shells can be suspended in various organic media, such as methanol, ethanol, pentanol, hexanol, octanol, octane, and decane, by a gradual solvent exchange. At this stage of the procedure the shells contain the respective organic solvent. Oil suspensions in water are then formed by transferring the particles from the organic media into water, without the use of any further surfactant addition. By an additional adsorption step employing phospholipids, it is possible to obtain a dispersion of shells in organic solvents containing an aqueous solution inside. AFM measurements are provided which show that the shells preserve their integrity in the different solvents. Confocal microscopy is employed to demonstrate encapsulation of solvents and the presence of lipids. Copyright 1999 Academic Press.

Interleukin-1-induced sickness behavior depends on behavioral lateralization in mice

Inter-individual differences in brain-immune interactions have been demonstrated previously in mice using lateralization as a behavioral trait of population heterogeneity. Lipopolysaccharide (LPS), which is known to induce neurochemical, neuroendocrine, and immune responses depending on lateralization, is also able to induce sickness behavior, via the production of interleukin-1 (IL-1). The objective of this study was to determine whether lateralization can influence the behavioral response to LPS and to IL-1. To test this hypothesis, adult female C3H mice, previously selected for paw preference in a food reaching task, were injected intraperitoneally (i.p.) with 0.75 microg LPS or 0.75 microg recombinant IL-1beta. Sickness induced by these molecules was measured by depressed social behavior, increased immobility, loss of body weight, and reduced food intake during the 6 h following injection. LPS-induced sickness was similar in right- and left-pawed mice. In contrast, IL-1-induced sickness behavior was dependent on behavioral lateralization. IL-1-induced depression of social investigation was more pronounced in right-pawed mice than in left-pawed animals. Likewise, IL-1-induced immobility was more important in right-pawed mice. There was a similar trend for food intake to be lower and loss of body weight to be higher in right-pawed mice than in left-pawed animals. These results demonstrate that right-pawed mice are more sensitive to IL-1-induced sickness than left-pawed animals. They extend our previous data showing a greater susceptibility to stress of right-pawed animals. The existence of inter-individual differences in the reactivity to stress or immune activation may be useful to study the mechanisms of the various strategies used by an individual in response to environmental aggressions.

In the mouse, the corticoid stress response depends on lateralization

The influence of brain/behavioral lateralization on the neuroendocrine stress response was studied in the mouse. Using a paw preference test in a food reaching task, mice were classified as left-pawed, ambidextrous or right-pawed. Plasma levels of corticosterone (CS) were measured in basal conditions, 4 h after an intraperitoneal injection of lipopolysaccharide (LPS) or after a short period of restraint. In unstressed control mice, plasma levels of corticosterone were higher in left-pawed animals as compared to ambidextrous. LPS increased plasma levels of CS to similarly high levels, around 600 ng/ml, in the three experimental groups. By contrast after 1 h of restraint, the increased CS levels, lower to those observed after LPS injection, were higher in left-pawed mice as compared to right-pawed animals. These results are the first demonstration that activation of the hypothalamic-pituitary-adrenal axis observed during the stress response to a physical stimulus may be related to lateralization.

Hormonal regulation of rat testicular gamma-glutamyl-transpeptidase "in vivo" and "in vitro"

The hormonal regulation of gamma-glutamyl transpeptidase (gamma-GTP), an enzyme marker of Sertoli cells, was studied in immature rats that received 50 micrograms/day of testosterone propionate (TP) during 6 days to suppress pituitary LH and FSH. Suppression of LH was monitored indirectly by the determination of intratesticular levels of testosterone and suppression of FSH by radioimmunoassay of serum FSH. Enzyme activity in the testis decreased in parallel to intratesticular testosterone suppression, and it did recover up to control values when animals received 500 micrograms/day of TP, a dose that was able to maintain intratesticular testosterone at normal levels. beta-glucuronidase, another enzyme marker of Sertoli cells, was not affected by these treatments. A significant decrease in gamma-GTP was detected 24h after significant suppression of intratesticular testosterone and it returned to control levels 2 days after increasing the dose of TP to 500 micrograms/day. Administration of FSH to rats with depletion of intratesticular testosterone was able to maintain testicular gamma-GTP at control levels. An stimulatory action of FSH could also be demonstrated in primary Sertoli cell cultures. It is concluded that testicular gamma-GTP is under the regulation of both androgens and FSH while beta-glucuronidase is not. Eventhough the function of gamma-GTP in the testis is not known, the key role that it plays in other tissues suggests that it might be important in the regulation of Sertoli cell-germ cell interactions.

Relative cellular distribution of particulate androgen binding between sertoli and germ cells in rat testis

An androgen binding activity with characteristics similar to ABP is present in a particulate fraction (105,000 g pellet) obtained by differential centrifugation of seminiferous tubules, impure Sertoli cells and impure germ cells homogenates. Purification of germ cells through albumin gradients, results in almost a complete loss of androgen binding activity in the purified germ cell suspensions. Furthermore, Sertoli cell enriched testes from 22-, 32- and 40-day old rats showed increases in particulate androgen binding, when compared to matched controls, parallel to increments in the activity of a Sertoli cell marker enzyme (beta-glucuronidase). These results suggest that particulate androgen binding activity is only present in Sertoli cells and this protein may play a role in the compartmentalization of androgens in the testis.