Dual αV-integrin and neuropilin-1 targeting peptide CEND-1 plus nab-paclitaxel and gemcitabine for the treatment of metastatic pancreatic ductal adenocarcinoma: a first-in-human, open-label, multicentre, phase 1 study.

BACKGROUND: CEND-1 is a novel cyclic peptide that targets αV integrins and neuropilin-1 and enhances tumour delivery of co-administered anticancer drugs. We investigated the safety, tolerability, and biological activity of CEND-1 in patients with metastatic pancreatic ductal adenocarcinoma in combination with nab-paclitaxel and gemcitabine. METHODS: This open-label, multicentre, phase 1 study, conducted at three hospitals in Australia, enrolled participants aged 18 years or older with histologically confirmed metastatic pancreatic ductal adenocarcinoma who had one or more lesions measurable on MRI or CT, an Eastern Cooperative Oncology Group performance status score of 0 or 1, and a life expectancy of at least 3 months. Exclusion criteria included previous chemotherapy and brain metastases or other malignancy (unless receiving curative intent). There was no randomisation or masking. CEND-1 monotherapy was given as an intravenous fluid bolus on day 1 of a run-in phase of 7 days (0·2-3·2 mg/kg) followed by CEND-1 plus intravenous gemcitabine (1000 mg/m2) and nab-paclitaxel (125 mg/m2) on days 1, 8, and 15 of 28-day treatment cycles until disease progression. The primary safety endpoints were incidence, severity, and duration of treatment-emergent and treatment-related adverse events; overall survival; and clinical laboratory results, which were all assessed in the safety population. This study is registered with ClinicalTrials.gov, NCT03517176, and the Australian New Zealand Clinical Trials Registry, ACTRN12618000804280. FINDINGS: Between Aug 13, 2018, and Nov 30, 2019, 31 patients were enrolled (eight in the dose-escalation phase [cohort 1a] and 23 in the expansion phase [cohort 1b]). Two patients were excluded from the efficacy population. No CEND-1 dose-limiting toxicities were observed in the safety population (n=31). The most common grade 3 or 4 events were neutropenia (17 [55%] patients), anaemia (eight [26%]), leukopenia (five [16%]), and pulmonary embolism (four [13%]). Serious adverse events occurred in 22 (71%) patients, mostly related to disease progression. Ten deaths occurred during the study due to progression of metastatic pancreatic cancer (n=9) and a left middle cerebral artery stroke (n=1). In the efficacy population (n=29), 17 (59%) patients had an objective response, including one complete response and 16 partial responses. After a median follow-up of 26 months (IQR 24-30), median overall survival was 13·2 months (95% CI 9·7-22·5). INTERPRETATION: CEND-1 with nab-paclitaxel and gemcitabine has an acceptable safety profile, with no dose-limiting toxicities and encouraging activity. Adverse events were generally consistent with those seen with nab-paclitaxel and gemcitabine. Further randomised trials to determine the efficacy of CEND-1 are warranted. FUNDING: DrugCendR Australia Pty.

Immunotherapy use in oesophagogastric cancers-a review of the literature.

Cancers of the upper gastrointestinal tract are a leading cause of cancer-related death world-wide and historically have a poor prognosis. The incidence and histology of these cancers have varied temporally and geographically over the last three decades, with an emerging understanding of the differences in the molecular and genetic profiles across different subgroups. Management of oesophagogastric cancers is by a multidisciplinary team with utilisation of surgery, radiotherapy and systemic treatments in combinations where appropriate. Immune checkpoint inhibition (ICI) has drastically changed the treatment landscape of multiple solid malignancies in the last 5 years. In oesophagogastric cancer, clinical trials have only recently shown activity that is often associated with the molecular characteristics of these tumours, in particular PD-L1 scores or microsatellite instability (MSI-H). This review looks to present the pivotal trials in this space, discuss the complexities between trials that may explain the disparate results and assess the benefit ICI offers in the treatment landscape at present.

Targeting Mutated KRAS Genes to Treat Solid Tumours.

Kirsten rat sarcoma (KRAS) is one of the most frequently mutated oncogenes in solid tumours. It encodes an important signalling pathway that drives cellular proliferation and growth. It is frequently mutated in aggressive advanced solid tumours, particularly colorectal, lung and pancreatic cancer. Since the first mutated KRAS was discovered in the 1980s, decades of research to develop targeted inhibitors of mutant KRAS have fallen short of the task, until recently. Multiple agents are now in clinical trials, including specific mutant KRAS inhibitors, pan-KRAS inhibitors, therapeutic vaccines and other targeted inhibitors. Mutant-specific KRAS G12C inhibitors are the most advanced, with two inhibitors, adagrasib and sotorasib, achieving approval in 2021 for the second-line treatment of patients with KRAS G12C mutant lung cancer. In this review, we summarise the importance of mutant KRAS in solid tumours, prior attempts at inhibiting mutant KRAS, and the current promising targeted agents being investigated in clinical trials, along with future challenges.

Pancreatic, periampullary and biliary cancer with liver metastases: Should we consider resection in selected cases?

AIM: To analyse the safety and efficacy of curative intent surgery in biliary and pancreatic cancer. METHODS: An extensive literature review was performed using MEDLINE, Google Scholar and EMBASE to identify articles regarding hepato-pancreatoduodenectomy or resection of liver metastasis in patients with pancreatic, biliary tract, periampullary and gallbladder cancers. RESULTS: A total of 19 studies were identified and reviewed. Major hepatectomy was undertaken in 391 patients. The median overall survival for pancreatic cancer ranged from 5-36 mo and for biliary tract/gallbladder cancer, it was 8-38 mo. The 30 d mortality rate was only 1%-9%. Overall Survival was significantly better for patients, who had good response to neoadjuvant chemotherapy, underwent metachronous liver resection and who had intestinal type tumours. CONCLUSION: Resection of liver metastases in pancreatic and biliary cancers may provide survival benefit without compromising safety and quality of life in a very select group of patients. These data may be utilised to formulate selection criteria that may allow future investigation of resection in the era of more effective systemic therapy.

Targeted Therapies in Elderly Patients with Metastatic Colorectal Cancer: A Review of the Evidence.

Metastatic colorectal cancer (mCRC) is the third leading cause of cancer deaths worldwide. As the population of the western world ages, the incidence of colorectal tumours among elderly patients is increasing and consequently so is the demand for treatments for elderly patients. Unfortunately, elderly patients (≥65 years) often go untreated and they are also under-represented in clinical trials. Yet there is some evidence suggesting that 'fit' elderly patients have similar outcomes and tolerance to chemotherapy treatment to their younger counterparts (although the definition of fitness in the elderly population is still a matter of debate). The evidence supporting the administration of new targeted therapies in patients older than 65 years is scarce and more research is needed. In this paper, we review all the available data concerning the use of targeted therapies for mCRC in patients older than 65 years of age and discuss the differences between this age subgroup and younger patients.

Rural populations have equal surgical and survival outcomes in metastatic colorectal cancer.

OBJECTIVE: Previous Australian studies have suggested poorer survival of patients with colorectal cancer in remote areas. To date no studies have assessed the geographic disparity in patients with metastatic disease. This retrospective cohort study looks at geographic differences in the surgical care and survival of patients with metastatic colorectal disease. The paper utilises data from the South Australian Clinical Registry for Metastatic Colorectal Cancer (SACRMCC). DESIGN, PARTICIPANTS, INTERVENTIONS AND MAIN OUTCOME MEASURES: Data on patients' socio-economic status, primary and metastatic tumour characteristics, treatment and survival was extracted from the SACRMCC database. A binomial model analysis was used to identify geographical differences in the surgical treatment of patients and a Cox proportional hazards model was used to identify any geographic differences in survival. RESULTS: The findings showed no differences in the diagnosis of liver metastases or provision of liver surgery between geographic areas, however there was a reduced likelihood of liver surgery with increasing age. The median overall survival rate, from the date of diagnosis of metastatic disease, was 20.0 months and the distribution by geographic remoteness was 19.1 months, 20.2 months, 22.0 months and 20.4 months in Major Cities, Inner Regional, Outer Regional and Remote areas respectively. This was not statistically significant. CONCLUSION: Overall, there was no evidence of a geographical disparity in the diagnosis, surgical treatment or survival in metastatic colorectal cancer. This may be due to the shift toward centralising surgical care in South Australia. Nevertheless, there remains a need to improve the uptake of surgical care in the growing elderly population.

Equivalence of outcomes for rural and metropolitan patients with metastatic colorectal cancer in South Australia.

OBJECTIVE: To compare the management and outcome of rural and metropolitan patients with metastatic colorectal cancer (mCRC) in South Australia. DESIGN, SETTING AND PATIENTS: Retrospective cohort study of patients with mCRC submitted to the South Australian mCRC registry between 2 February 2006 and a cut-off date of 28 May 2012. MAIN OUTCOME MEASURES: Differences in oncological and surgical management and overall survival (calculated using the Kaplan-Meier method) between city and rural patients. RESULTS: Of 2289 patients, 624 (27.3%) were rural. There was a higher proportion of male patients in the rural cohort, but other patient characteristics did not significantly differ between the cohorts. Equivalent rates of chemotherapy administration between city and rural patients were observed across each line of treatment (first line: 56.0% v 58.3%, P = 0.32; second line: 23.3% v 22.5%, P = 0.78; and third line: 10.1% v 9.3%, P = 0.69). A higher proportion of city patients received combination chemotherapy in the first-line setting (67.4% v 59.9%; P = 0.01). When an oxaliplatin combination was prescribed, oral capecitabine was used more frequently in rural patients (22.9% v 8.4%; P < 0.001). No significant difference was seen in rates of hepatic resection or other non-chemotherapy treatments between cohorts. Median overall survival was equivalent between city and rural patients (14.6 v 14.9 months, P = 0.18). CONCLUSION: Patterns of chemotherapy and surgical management of rural patients with mCRC in SA are equivalent to their metropolitan counterparts and lead to comparable overall survival. The centralised model of oncological care in SA may ensure rural patients gain access to optimal care.

Can we accurately report PTEN status in advanced colorectal cancer?

BACKGROUND: Loss of phosphatase and tensin homologue (PTEN) function evaluated by loss of PTEN protein expression on immunohistochemistry (IHC) has been reported as both prognostic in metastatic colorectal cancer and predictive of response to anti-EGFR monoclonal antibodies although results remain uncertain. Difficulties in the methodological assessment of PTEN are likely to be a major contributor to recent conflicting results. METHODS: We assessed loss of PTEN function in 51 colorectal cancer specimens using Taqman® copy number variation (CNV) and IHC. Two blinded pathologists performed independent IHC assessment on each specimen and inter-observer variability of IHC assessment and concordance of IHC versus Taqman® CNV was assessed. RESULTS: Concordance between pathologists (PTEN loss vs no loss) on IHC assessment was 37/51 (73%). In specimens with concordant IHC assessment, concordance between IHC and Taqman® copy number in PTEN loss assessment was 25/37 (68%). CONCLUSION: Assessment PTEN loss in colorectal cancer is limited by the inter-observer variability of IHC, and discordance of CNV with loss of protein expression. An understanding of the genetic mechanisms of PTEN loss and implementation of improved and standardized methodologies of PTEN assessment are required to clarify the role of PTEN as a biomarker in colorectal cancer.

A descriptive study of persistent oxaliplatin-induced peripheral neuropathy in patients with colorectal cancer.

BACKGROUND: Prolonged neurotoxicity after systemic chemotherapy has the potential to impact on quality of life. We explored the frequency of persistent peripheral neuropathy in patients who received oxaliplatin for colorectal cancer at two local centres. PATIENTS AND METHODS: Questionnaires were sent to patients who completed treatment with oxaliplatin for colorectal cancer at least 20 months prior to entering the study. Neuropathy questions were adapted from the FACT/GOG-Ntx (V.4) questionnaire. RESULTS: Of the 56 eligible patients, 27 returned the questionnaire. Twenty-five patients (93 %) experienced neuropathic symptoms during their treatment; 11 had grade-2, and two had grade-3 symptoms. At the time of completing the questionnaire, 17 patients (63.0 %; 95%CI 43.9-79.4 %) were still symptomatic with 12 patients (44.4 %; 95%CI 26.8-63.3) having grade-2 or grade-3 symptoms and three patients (11.1 %; 95%CI 2.9-27.3) having grade-3 neuropathic symptoms. Participants who received more than 900 mg/m2 oxaliplatin had a significantly higher risk of persistent grade-2 or grade-3 neuropathy (p = 0.031, RR = 8.3 95%CI = 1.2-57.4). There was a trend toward increased risk of persistent neuropathy of any grade among participants with a history of regular alcohol use (p = 0.051; RR = 1.7 95%CI 1.0-2.8). CONCLUSION: Persistent oxaliplatin-induced neuropathy is not as uncommon as previously suggested, and the rate of grade-2 and grade-3 symptoms could be considerably higher than previous reports.

Hepatic encephalopathy associated with cancer or anticancer therapy.

Hepatic encephalopathy is an uncommon cause of neurologic deterioration associated with hyperammonemia, which results from hepatic dysfunction or altered ammonia metabolism. Often overlooked, hyperammonemia may occur via any of several pathophysiological processes, and in the setting of malignancy, it is a potentially reversible cause of confusion and coma. Hepatic dysfunction as a result of malignant infiltration, chemotherapeutic toxicities, targeted anticancer therapies, reactivation hepatitis, portosystemic shunting, and transarterial chemoembolization (TACE) is discussed, and an approach to etiological diagnosis and management is outlined.

Rechallenge with oxaliplatin and fluoropyrimidine for metastatic colorectal carcinoma after prior therapy.

OBJECTIVES: Patients with advanced colorectal cancer (CRC) who have received oxaliplatin, 5-fluoropyrimidine, and irinotecan chemotherapy (with or without bevacizumab) and antiepidermal growth factor receptor therapy (if KRAS is wild type) have no further standard treatment options. Although repeating a prior chemotherapy [in particular, oxaliplatin and fluoropyrimidine (FOX)] is an option, there is very little evidence in the literature for this approach; thus, we reviewed our registry to assess the frequency and outcome of rechallenging with FOX. METHODS: Patients who had been rechallenged with FOX were identified from the South Australian metastatic CRC database. Patient characteristics were analyzed, and tumor response was retrospectively assessed using Response Evaluation Criteria in Solid Tumors criteria. RESULTS: Twenty patients were eligible for inclusion in this analysis. The number of prior lines of therapy received for metastatic CRC was 4 lines for 2 patients, 3 lines for 6 patients, 2 lines for 7 patients, and 1 line for 3 patients, with 3 patients having received oxaliplatin as adjuvant therapy. Four patients had received bevacizumab previously, 7 patients had undergone antiepidermal growth factor receptor treatment, and 4 patients had undergone liver resection earlier. Response rate was 18%, and 47% had stable disease. The median progression-free survival was 3.7 months, median overall survival was 7.8 months, and 1-year survival was 37%. CONCLUSIONS: In this selected population, there is evidence of modest activity of rechallenge with FOX chemotherapy, although radiologic response is uncommon.

Cetuximab in metastatic colorectal cancer.

Management of metastatic colorectal cancer has evolved in the last 10 years, with the availability of targeted therapies resulting in improvement in quality of life and overall survival. Cetuximab is a chimeric monoclonal antibody that binds to the EGF receptor, and the net effects are inhibition of tumor growth, invasion, angiogenesis and metastasis. Cetuximab binding to the EGF receptor is also known to augment the effects of chemotherapy and radiotherapy. Only tumors expressing wild-type KRAS respond to cetuximab and improvements in progression-free survival and overall survival are seen, whereas patients with mutant KRAS are considered to be resistant. Cetuximab is currently available worldwide for use as monotherapy or in combination with chemotherapy in first-, second- or third-line settings in metastatic colorectal cancer patients with wild-type KRAS.

Reversing Hyperammonemia in Neuroendocrine Tumors.

Ammonia is a neurotoxin that is normally cleared by the intact liver and if not, hyperammonemia results in hepatic encephalopathy. Hyperammonemia may be owing to primary or secondary causes. Early diagnosis is important to prevent permanent brain damage. Advanced malignancy involving the liver is associated with hyperammonemia as a result of abnormality of the portal venous system or massive hepatic tumor burdon. Neuroendocrine tumors are an example of a malignant process that frequently involves the liver but despite this, may still have a relatively good prognosis, and are often characterized by chronic manageable symptoms and slow progression. Hyperammonemia in neuroendocrine tumor would represent a potentially reversible but ongoing process associated with an indolent malignancy. We present 2 cases that are examples of this diagnosis and discuss the diagnostic and management issues that may arise.

Contrast induced hyperthyroidism due to iodine excess.

Iodine induced hyperthyroidism is a thyrotoxic condition caused by exposure to excessive iodine. Historically this type of hyperthyroidism has been described in areas of iodine deficiency. With advances in medicine, iodine induced hyperthyroidism has been observed following the use of drugs containing iodine-for example, amiodarone, and contrast agents used in radiological imaging. In elderly patients it is frequently difficult to diagnose and control contrast related hyperthyroidism, as most of these patients do not always present with typical signs and symptoms of hyperthyroidism. Treatment can be very challenging as drugs commonly used to treat hyperthyroidism have little effect on already formed thyroid hormone due to iodine excess.