EGFR-targeting therapy as an evolving concept: learning from nimotuzumab clinical development

Epidermal growth factor receptor (EGFR)-targeted therapies have been extensively evaluated in the clinic for different tumor localizations and using different EGFR-targeting products, either registered or still in clinical development. Nonetheless, there still is a long way to go to optimize the clinical benefit from EGFR-targeted therapies. In this article we briefly discuss on current paradigms guiding the use of EGFR-targeting agents in the clinic, and on new emergent concepts. The discussion is largely based on experiences from the clinical development of the monoclonal antibody nimotuzumab, which has shown a quite particular clinical profile, characterized by a very low toxicity. In order to optimize the design of EGFR-targeting therapies, clinical researchers should take into account the interconnection between the EGFR pathway and other cellular pathways. Thus, clinical trials need to incorporate more translational research.

Tumour responses following a steroid switch from prednisone to dexamethasone in castration-resistant prostate cancer patients progressing on abiraterone

BACKGROUND

Abiraterone is a CYP17A1 inhibitor that improves survival in castration-resistant prostate cancer (CRPC). Abiraterone is licensed in combination with prednisone 5 mg twice daily to prevent a syndrome of secondary mineralocorticoid excess. We hypothesised that a 'steroid switch' from prednisone to dexamethasone would induce secondary responses in patients progressing on abiraterone and prednisone 5 mg b.i.d.

METHODS

We performed a 'steroid switch' in patients with CRPC at PSA progression on abiraterone and prednisolone. Patients were monitored for secondary declines in PSA, radiological tumour regression and toxicity.

RESULTS

A retrospective analysis of 30 CRPC patients who underwent a steroid switch from prednisolone to dexamethasone while on abiraterone was performed. A total of six patients (20%) had a ⩾50% PSA decline that was confirmed by a second PSA level at least 3 weeks later. In all, 11 patients (39.2%) had a confirmed ⩾30% PSA decline. Median time to PSA progression on abiraterone and dexamethasone was 11.7 weeks (95% CI: 8.6-14.8 weeks) in the whole cohort and 27.6 weeks (95% CI: 14.5-40.7 weeks) in patients who achieved a confirmed 50% PSA decline. Nine patients had RECIST evaluable disease: two of these patients had RECIST partial response, six patients had stable disease and one patient had progressive disease at the first imaging assessment. Treatment was well tolerated, with no grade 3 and grade 4 adverse events. One patient had to be reverted to prednisolone because of grade 2 hypotension.

CONCLUSIONS

Durable PSA responses occur in up to 40% of patients following a 'steroid switch' for PSA progression on abiraterone and prednisone. Studies are ongoing to elucidate the mechanisms underlying this response.

Adenosine-induced cardiac arrest in complex cerebral aneurysms surgery: an Italian single-center experience

AIM

Even if endovascular techniques are improving, treatment of complex intracranial aneurysms still remains a neurosurgeon challenge. Adenosine administration, producing a brief and profound systemic hypotension, seems to improve surgical aneurysm visualization facilitating its exclusion with less risks of rupture. In our retrospective study we confirmed that adenosine advantages could be determinant for an optimal surgical result.

METHODS

We retrospectively reviewed all unruptured complex cerebral aneurysms surgically treated in our institution between August 2009 and April 2012. Treatment of those aneurysms was surgical, with proximal temporary artery occlusion or adenosine induced flow arrest. We compared the two different techniques, evaluating intra- and postoperative data; a three-month follow-up including a neurological assessment, cerebral angiography and echocardiography for the adenosine group was performed.

RESULTS

Twenty-four patients were collected in our study. Eleven patients underwent traditional temporary proximal clipping while in 13 patients intraoperative adenosine was used. Most common location was paraclinoid region. We did not observe any complication in the adenosine group. Adenosine was well tolerated, spontaneous recovery of sinusal cardiac rhythm was observed even at high and subsequent doses. The Intensive Care Unit and Hospital length of stay were shorter in adenosine group. A three-month follow-up did not show cardiac abnormalities with good angiographic aneurysms exclusion.

CONCLUSION

We observed that adenosine administration allowed an easier clipping thanks to a reduced wall tension in a clearer surgical field without cardiological adverse events. In our opinion adenosine induced arrest technique could be an efficacious, harmless and reliable alternative strategy for surgical treatment of complex cerebral aneurysms.

An inexpensive and worldwide available digital image analysis technique for histological fibrosis quantification in chronic hepatitis C

Hepatic fibrosis staging is based on semiquantitative scores. Digital imaging analysis (DIA) appears more accurate because fibrosis is quantified in a continuous scale. However, high cost, lack of standardization and worldwide unavailability restrict its use in clinical practice. We developed an inexpensive and widely available DIA technique for fibrosis quantification in hepatitis C, and here, we evaluate its reproducibility and correlation with semiquantitative scores, and determine the fibrosis percentage associated with septal fibrosis and cirrhosis. 282 needle biopsies staged by Ishak and METAVIR scores were included. Images of trichrome-stained sections were captured and processed using Adobe(®) Photoshop(®) CS3 and Adobe(®) Bridge(®) softwares. The percentage of fibrosis (fibrosis index) was determined by the ratio between the fibrosis area and the total sample area, expressed in pixels calculated in an automated way. An excellent correlation between DIA fibrosis index and Ishak and METAVIR scores was observed (Spearman's r = 0.95 and 0.92; P < 0.001, respectively). Excellent intra-observer reproducibility was observed in a randomly chosen subset of 39 biopsies with an intraclass correlation index of 0.99 (95% CI, 0.95-0.99). The best cut-offs associated with septal fibrosis and cirrhosis were 6% (AUROC 0.97, 95% CI, 0.95-0.99) and 27% (AUROC 1.0, 95% CI, 0.99-1), respectively. This new DIA technique had high correlation with semiquantitative scores in hepatitis C. This method is reproducible, inexpensive and available worldwide allowing its use in clinical practice. The incorporation of DIA technique provides a more complete evaluation of fibrosis adding the quantification to architectural patterns.

First Report of Wood Canker Caused by Neoscytalidium dimidiatum on Grapevine in California

In May 2012 in the Coachella valley, Riverside County, California, the decline of vines in table grape (Vitis vinifera) vineyards was observed. Foliar symptoms consisted of shoot blight with wilting and necrosis of leaves and drying and shriveling of berries. In some cases, the entire vine collapsed in the middle of the growing season (apoplexia). Wood cankers in the spurs, cordons, and trunks of affected vines were also present. The nine isolates recovered from the cankers were identified as Neoscytalidium dimidiatum (Penz.) Crous & Slippers based on morphological characteristics and DNA sequence comparisons. Two isolates were grown on potato dextrose agar (PDA) medium and a total of 50 conidia were measured per isolate. Conidia were ellipsoid to ovoid, with a truncate base and an acutely rounded apex, initially aseptate, becoming brown and two-celled at maturity, 7.2 ± 1.2 μm × 3.8 ± 0.4 μm. The rDNA internal transcribed spacer (ITS), and β-tubulin (BT) loci were amplified using primer pairs and methods previously described (4). A total of five isolates were sequenced. The DNA sequences of one N. dimidiatum grapevine isolate (UCR-Neo1) were deposited in the GenBank database (ITS, KC937066; BT, KC937067). Pathogenicity tests were performed by inoculating 12 grape cuttings cv. Thompson Seedless with isolate UCR-Neo1 and 12 control cuttings with sterile medium using a technique previously described (1). The experiment was repeated twice. After 20 weeks of incubation period in the greenhouse, the lesions length produced by N. dimidiatum averaged 13.5 mm and was significantly longer (P < 0.05) from the control (average 3 mm). N. dimidiatum was reisolated from all the inoculated plants and identified by colony morphology. The incidence of N. dimidiatum in table grape vineyards of the Coachella valley has been estimated at 15%, with nine vines infected out of 60 vines total. This pathogen has been identified in California in walnut nursery causing the death of trees due to the development of canker at the graft union (2). N. dimidiatum has also been identified as the causal agent of shoot blight, canker, and gummosis on citrus in Italy (3). The crop is also being grown in the Coachella valley and these findings warrant further investigation in order to determine the host range, distribution, and incidence of this pathogen in the area. References: (1) K. Baumgartner et al. Plant Dis. 97:912, 2013. (2) S. F. Chen et al. Plant Dis. 97:993, 2013. (3) G. Polizzi et al. Plant Dis 93:1215, 2009. (4) J. R. Urbez-Torres et al. Plant Dis. 92:519, 2008.

Soil diversity and hydration as observed by ChemCam at Gale crater, Mars

The ChemCam instrument, which provides insight into martian soil chemistry at the submillimeter scale, identified two principal soil types along the Curiosity rover traverse: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic soil component is representative of widespread martian soils and is similar in composition to the martian dust. It possesses a ubiquitous hydrogen signature in ChemCam spectra, corresponding to the hydration of the amorphous phases found in the soil by the CheMin instrument. This hydration likely accounts for an important fraction of the global hydration of the surface seen by previous orbital measurements. ChemCam analyses did not reveal any significant exchange of water vapor between the regolith and the atmosphere. These observations provide constraints on the nature of the amorphous phases and their hydration.

Trial proactive: A prospective, randomized, multicenter, open label phase III study of active specific immunotherapy with racotumomab plus best support treatment versus best support treatment in patients with advanced non-small cell lung cancer

TPS3123

Background: Gangliosides, especially NeuGc-GM3, are attractive targets for cancer immunotherapy. They are not expressed in normal human cells but are overexpressed and involved in tumor growth in several tumors (melanoma, neuroectodermal pediatric tumors and breast cancer). More than 70% of non-small cell lung cancers (NSCLC) express NeuGc-GM3. Racotumomab is an anti-idiotypic monoclonal antibody that mimics NeuGc gangliosides. Administered as a therapeutic vaccine it acts as an antigen, inducing a cellular and humoral immune response against NeuGc-GM3 and other gangliosides. Previous trials have shown its low toxicity and high immunogenicity. Recently, a multicenter, randomized, placebo controlled, double-blind trial in 176 NSCLC (IIIB and IV) patients with at least stable disease after first line therapy and progression free at inclusion showed a statistical significant survival benefit in favor of racotumomab. Methods: This phase III, multinational, randomized (1:1), open label trial will evaluate efficacy and safety of racotumomab plus best supportive care (BSC) versus BSC. 1,082 patients with NSCLC (stages III or IV) showing response or stable disease after standard first-line therapy (platinum-based chemotherapy and radiotherapy) are eligible if they remain free of progression and have a PS ≤ 1. Vaccination consists of an induction period (5 doses, 1 every 14 days) followed by a maintenance period (1 dose every 28 days, until worsening of the PS or unacceptable toxicity occur). Upon progression other onco-specific therapies may be used and vaccination can continue. Overall survival (OS) will be compared using a two-sided log rank test at a significance level (alpha) of 0.05 with 90% power to detect a hazard ratio of 0.79. There will be 3 interim analyses and a final analysis when 758 deaths occur. So far 190 patients have been randomized. An Independent Data Monitoring Committee oversees the study and has so far (last meeting September 2012) concluded that the trial can continue. The trial is registered in ClinicalTrials.gov under NCT01460472. Clinical trial information: NCT01460472.

Active immunotherapy in patients with progressive disease (PD) after first-line therapy: Racotumomab experience

3086

Background: Racotumomab is a therapeutic vaccine that induces a cellular and humoral immune response against NeuGc-containing gangliosides expressed in several tumors but not in normal human tissues. A previous randomized, double blinded, placebo-controlled trial has demonstrated low toxicity of racotumomab and a statistically significant benefit in overall survival (OS) in patients with advanced non-small-cell lung cancer (NSCLC) who had achieved partial or complete response or disease stabilization after first line therapy. Methods: An open, non-randomized study was performed to evaluate if racotumomab could also be beneficial in patients with progressive disease. Patients with recurrent and advanced stages (IIIB/IV) of NSCLC, in progression after completion of first-line onco-specific treatment as per the NCCN Oncology Therapeutic Guidelines (surgery, chemotherapy and/or radiotherapy) were included in the study. Most of them had received 4 to 6 cycles of cisplatin/vinblastin. Vaccination consisted of 5 intradermic doses of racotumomab (1 every 14 days), followed by 1 dose every 28 days until patient refusal or worsening of ECOG status. The patients did not receive second-line therapy. Results: 180 patients were included in an intent to treat (ITT) survival analysis (Kaplan Meier estimate), after at least 10 months of follow-up. Median survival was 8.06 months. OS rate (%) at 24 months was 21%. A control group of 85 consecutive patients treated at the same institution by the same investigators, who did not receive second-line therapy or racotumomab showed a median survival of 6.26 months (log rank test p= 0.011). OS rate (%) at 24 months was only 7%. A per protocol survival analysis including only the 124 patients (68.8%) who received ≥ 5 doses of racotumomab showed a median survival of 12 months. OS rate (%) at 24 months was 30%. Conclusions: Patients with PD after first-line treatment show favorable results in survival when vaccinated with racotumomab. This result is similar to previous clinical trials where racotumomab was administered to patients with objective response (partial or complete) or stable disease after first line therapy.

A view on EGFR-targeted therapies from the oncogene-addiction perspective

Tumor cell growth and survival can often be impaired by inactivating a single oncogen– a phenomenon that has been called as “oncogene addiction.” It is in such scenarios that molecular targeted therapies may succeed. among known oncogenes, the epidermal growth factor receptor (EGFR) has become the target of different cancer therapies. So far, however, the clinical benefit from EGFR-targeted therapies has been rather limited. a critical review of the large amount of clinical data obtained with anti-EGFR agents, carried out from the perspective of the oncogene addiction concept, may help to understand the causes of the unsatisfactory results. In this article we intend to do such an exercise taking as basis for the analysis a few case studies of anti-EGFR agents that are currently in the clinic. There, the “EGFR addiction” phenomenon becomes apparent in high-responder patients. We further discuss how the concept of oncogene addiction needs to be interpreted on the light of emerging experimental evidences and ideas; in particular, that EGFR addiction may reflect the interconnection of several cellular pathways. In this regard we set forth several hypotheses; namely, that requirement of higher glucose uptake by hypoxic tumor cells may reinforce EGFR addiction; and that chronic use of EGFR-targeted antibodies in EGFR-addicted tumors would induce stable disease by reversing the malignant phenotype of cancer stem cells and also by sustaining an anti-tumor T cell response. Finally, we discuss possible reasons for the failure of certain combinatorial therapies involving anti-EGFR agents, arguing that some of these agents might produce either a negative or a positive trans-modulation effect on other oncogenes. It becomes evident that we need operational definitions of EGFR addiction in order to determine which patient populations may benefit from treatment with anti-EGFR drugs, and to improve the design of these therapies.

Liana abundance, diversity, and distribution on Barro Colorado Island, Panama

Lianas are a key component of tropical forests; however, most surveys are too small to accurately quantify liana community composition, diversity, abundance, and spatial distribution - critical components for measuring the contribution of lianas to forest processes. In 2007, we tagged, mapped, measured the diameter, and identified all lianas ≥1 cm rooted in a 50-ha plot on Barro Colorado Island, Panama (BCI). We calculated liana density, basal area, and species richness for both independently rooted lianas and all rooted liana stems (genets plus clones). We compared spatial aggregation patterns of liana and tree species, and among liana species that varied in the amount of clonal reproduction. We also tested whether liana and tree densities have increased on BCI compared to surveys conducted 30-years earlier. This study represents the most comprehensive spatially contiguous sampling of lianas ever conducted and, over the 50 ha area, we found 67,447 rooted liana stems comprising 162 species. Rooted lianas composed nearly 25% of the woody stems (trees and lianas), 35% of woody species richness, and 3% of woody basal area. Lianas were spatially aggregated within the 50-ha plot and the liana species with the highest proportion of clonal stems more spatially aggregated than the least clonal species, possibly indicating clonal stem recruitment following canopy disturbance. Over the past 30 years, liana density increased by 75% for stems ≥1 cm diameter and nearly 140% for stems ≥5 cm diameter, while tree density on BCI decreased 11.5%; a finding consistent with other neotropical forests. Our data confirm that lianas contribute substantially to tropical forest stem density and diversity, they have highly clumped distributions that appear to be driven by clonal stem recruitment into treefall gaps, and they are increasing relative to trees, thus indicating that lianas will play a greater role in the future dynamics of BCI and other neotropical forests.

Nations' income inequality predicts ambivalence in stereotype content: how societies mind the gap

Income inequality undermines societies: The more inequality, the more health problems, social tensions, and the lower social mobility, trust, life expectancy. Given people's tendency to legitimate existing social arrangements, the stereotype content model (SCM) argues that ambivalence-perceiving many groups as either warm or competent, but not both-may help maintain socio-economic disparities. The association between stereotype ambivalence and income inequality in 37 cross-national samples from Europe, the Americas, Oceania, Asia, and Africa investigates how groups' overall warmth-competence, status-competence, and competition-warmth correlations vary across societies, and whether these variations associate with income inequality (Gini index). More unequal societies report more ambivalent stereotypes, whereas more equal ones dislike competitive groups and do not necessarily respect them as competent. Unequal societies may need ambivalence for system stability: Income inequality compensates groups with partially positive social images.