Use and outcomes from neoadjuvant chemotherapy in borderline resectable pancreatic ductal adenocarcinoma in an Australasian population

BACKGROUND

Use of neoadjuvant (NA) chemotherapy is recommended when pancreatic ductal adenocarcinoma (PDAC) is borderline resectable METHOD: A retrospective analysis of consecutive patients with localized PDAC between January 2016 and March 2019 within the Australasian Pancreatic Cancer Registry (PURPLE, Pancreatic cancer: Understanding Routine Practice and Lifting End results) was performed. Clinicopathological characteristics, treatment, and outcome were analyzed. Overall survival (OS) comparison was performed using log-rank model and Kaplan-Meier analysis.

RESULTS

The PURPLE database included 754 cases with localised PDAC, including 148 (20%) cases with borderline resectable pancreatic cancer (BRPC). Of the 148 BRPC patients, 44 (30%) underwent immediate surgery, 80 (54%) received NA chemotherapy, and 24 (16%) were inoperable. The median age of NA therapy patients was 63 years and FOLFIRINOX (53%) was more often used as NA therapy than gemcitabine/nab-paclitaxel (31%). Patients who received FOLFIRINOX were younger than those who received gemcitabine/nab-paclitaxel (60 years vs. 67 years, p = .01). Surgery was performed in 54% (43 of 80) of BRPC patients receiving NA chemotherapy, with 53% (16 of 30) achieving R0 resections. BRPC patients undergoing surgery had a median OS of 30 months, and 38% (9 of 24) achieved R0 resection. NA chemotherapy patients had a median OS of 20 months, improving to 24 months versus 10 months for patients receiving FOLFIRINOX compared to gemcitabine/nab-paclitaxel (Hazard Ratio (HR) .3, p < .0001).

CONCLUSIONS

NA chemotherapy use in BRPC is increasing in Australia. One half of patients receiving NA chemotherapy proceed to curative resection, with 53% achieving R0 resections. Patients receiving Infusional 5-flurouracil, Irinotecan and Oxaliplatin (FOLIRINOX) had increased survival than gemcitabine/nab-paclitaxel. Treatment strategies are being explored in the MASTERPLAN and DYNAMIC-Pancreas trials.

Assessing real-world outcomes in metastatic colorectal cancer with KRASG12C mutation

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Background: The KRASG12C mutation is present in 3% of colorectal cancer and is of particular interest given the recent development of specific targeting drugs. Previous data suggest KRAS (all) mutations may impact prognosis. Here we assess the clinical features and outcomes of real world patients with KRASG12C mutant metastatic colorectal cancer (mCRC) to explore any clinicopathologic associations and prognostic impact. Methods: Patients diagnosed with mCRC between January 2011 and December 2018 were included in this prospective mCRC registry. Patients with BRAF mutations, unknown or unspecified KRAS variants were excluded. Clinicopathologic features, treatment and overall survival (OS) were compared for RAS wildtype (RASWT) and KRASG12C mutant patients, and between KRASG12C and other (RASother) mutations. Results: Of 1308 patients analysed, 674 (52%) were RASmut, of whom 56 (8.3%) were KRASG12C. More patients with KRASG12C were female compared to RASother and RASWT (Table). No differences were observed in primary tumor location, number of metastatic sites and distribution of metastases. The proportion of patients undergoing metastasectomy was similar between KRASG12C and RASother, and KRASG12C and RASWT. There was no difference in the proportion of patients receiving systemic therapy. RASWT patients received more lines of therapy. Median OS was similar between KRASG12C, RASother, and RASWT: 31.7 vs 29.2 vs 31.8 months respectively (P = 0.545). Conclusions: KRASG12C mutations were observed in 4.3% of mCRC patients and in 8.3% of RAS mutant cases. Patients with KRASG12C have comparable clinical features to RASWT or RASother mCRC. Treatment and survival were also similar between groups. KRASG12C does not appear to be prognostic, but may be an important predictive biomarker as promising targeted therapies continue to be developed. [Table: see text]

Circulating tumor DNA as a potential marker of adjuvant chemotherapy benefit following surgery for localized pancreatic cancer

BACKGROUND

In early-stage pancreatic cancer, there are currently no biomarkers to guide selection of therapeutic options. This prospective biomarker trial evaluated the feasibility and potential clinical utility of circulating tumor DNA (ctDNA) analysis to inform adjuvant therapy decision making.

MATERIALS AND METHODS

Patients considered by the multidisciplinary team to have resectable pancreatic adenocarcinoma were enrolled. Pre- and post-operative samples for ctDNA analysis were collected. PCR-based-SafeSeqS assays were used to identify mutations at codon 12, 13 and 61 of KRAS in the primary pancreatic tumor and to detect ctDNA. Results of ctDNA analysis were correlated with CA19-9, recurrence-free and overall survival (OS). Patient management was per standard of care, blinded to ctDNA data.

RESULTS

Of 112 patients consented pre-operatively, 81 (72%) underwent resection. KRAS mutations were identified in 91% (38/42) of available tumor samples. Of available plasma samples (N = 42), KRAS mutated ctDNA was detected in 62% (23/37) pre-operative and 37% (13/35) post-operative cases. At a median follow-up of 38.4 months, ctDNA detection in the pre-operative setting was associated with inferior recurrence-free survival (RFS) [hazard ratio (HR) 4.1; P = 0.002)] and OS (HR 4.1; P = 0.015). Detectable ctDNA following curative intent resection was associated with inferior RFS (HR 5.4; P < 0.0001) and OS (HR 4.0; P = 0.003). Recurrence occurred in 13/13 (100%) patients with detectable ctDNA post-operatively, including in seven that received gemcitabine-based adjuvant chemotherapy.

CONCLUSION

ctDNA studies in localized pancreatic cancer are challenging, with a substantial number of patients not able to undergo resection, not having sufficient tumor tissue for analysis or not completing per protocol sample collection. ctDNA analysis, pre- and/or post-surgery, is a promising prognostic marker. Studies of ctDNA guided therapy are justified, including of treatment intensification strategies for patients with detectable ctDNA post-operatively who appear at very high risk of recurrence despite gemcitabine-based adjuvant therapy.

Utilisation of systemic therapy options in routine treatment of metastatic colorectal cancer in Australia

BACKGROUND

In the treatment of metastatic colorectal cancer (mCRC), exposure to all three active cytotoxic agents, 5-fluorouracil/capecitabine, irinotecan and oxaliplatin, improves overall survival. The addition of biologic agents (bevacizumab and cetuximab/panitumumab) further improves survival. The uptake of available systemic agents for mCRC in routine practice in Australia is poorly described.

METHODS

The ACCORD database was interrogated to determine demographics, treatments and outcomes for patients diagnosed with mCRC between 1 January 2011 and 1 January 2016 at six Melbourne centres.

RESULTS

About 1130 mCRC patients were identified: median age was 69 years (range 26-105); 61% had synchronous disease. KRAS status was known in 62%, of whom 49% were KRAS wild-type. At the time of analysis, 67% of all patients had commenced systemic treatment, 50% had received two or more lines of therapy and 19% of KRAS wild-type patients had received all five active drugs. Of KRAS-mutated patients, 35% had received all four Pharmaceutical Benefits Scheme-reimbursed active drugs. Patients who had not received chemotherapy included 72 patients who underwent metastasectomy alone. At a median follow up of 34 months, median overall survival was 25 months for all patients and 69 months for those who underwent metastasectomy.

CONCLUSION

In this community-based cohort, 33% of patients had not received any systemic therapy for mCRC, and few patients had received all available active systemic agents. As many patients remain alive, these figures will likely increase over time. The overall survival of patients with mCRC in this community-based cohort was 25 months and not dissimilar to that achieved in recent clinical trials.

Potential role of circulating tumor DNA (ctDNA) in the early diagnosis and post-operative management of localised pancreatic cancer

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Background: Pancreatic cancer remains a devastating disease, with the diagnosis typically being made late. ctDNA has shown promise as a screening test for various tumor types. The detection of ctDNA post curative intent surgery has been associated with a high risk of recurrence in multiple solid tumors. We explored the potential of ctDNA to improve pancreatic cancer outcomes. Methods: Data from separate US and Australian series were combined. Plasma samples were collected prior to surgery in both studies and post-operative samples were collected in Australia from cases undergoing curative intent surgery. Clinicians were blinded to ctDNA results and adjuvant therapy was at clinician discretion. Tissue samples from both series were analyzed at Johns Hopkins University. Next generation sequencing was used to search for somatic KRAS mutations in the primary tumors and in cell-free DNA in the plasma. Clinico-pathologic, treatment and outcome data were collected. Results: 119 pts had a ctDNA sample at diagnosis (median age 67 years, 56.3% male). Sixty six pts (55.5 %) had detectable ctDNA, including 3/7 (42.9%) with stage I disease, 54/99 (54.5%) with stage II disease, 4/8 (50%) with stage III disease and 5/5 (100%) with metastases. Specific codon 12 KRAS (G12D, G12V or G12R) mutations were identified in the tumor tissue of 12/16 (75%) patients who had a ctDNA sample collected post-surgery. At a median follow-up of 15.2 months, 7/12 (58.3%) pts had recurred, including 3/8 (37.5%) with no detectable ctDNA and 4/4 (100%) with detectable ctDNA post-surgery (HR 4.9, p = 0.04). Detectable ctDNA post-surgery was significantly associated with poor overall survival (HR 6.93, p = 0.006), with a median of 8 months for pts with detectable ctDNA. Conclusions: ctDNA shows promise as a pancreatic cancer screening test, being detectable in a high proportion of pts with early stage disease. The detection of ctDNA post operatively predicts a very high risk of recurrence. The clinical utility of ctDNA to guide adjuvant therapy decision making, and its potential as a real-time marker of treatment effect, are being explored in further studies. Clinical trial information: ACTRN12612000763842.

FOLFOX and intensified split-course chemoradiation as initial treatment for rectal cancer with synchronous metastases

BACKGROUND

Optimal initial management of rectal carcinoma with synchronous metastases (RCSM) is controversial - both for patients being treated with curative and palliative intent. This study aims to evaluate the use of an upfront treatment strategy combining FOLFOX chemotherapy with split-course pelvic chemoradiation (FOLFOX + CRT) for patients with RCSM.

MATERIAL AND METHODS

An analysis of all patients who commenced treatment with FOLFOX + CRT at our institutions between January 2009 and June 2014 was performed. The regimen consisted of a total of 12 weeks of treatment with split-course pelvic chemoradiation (50.4Gy with concurrent oxaliplatin and 5-FU) alternating with FOLFOX chemotherapy. Restaging imaging was performed following treatment, with subsequent management as per local standard of care.

RESULTS

78 patients (15 with resectable liver-only metastases) were identified. 77 (99%) completed at least 45Gy of radiation and 87% completed ≥75% of planned dose intensity of both oxaliplatin and 5FU. Two (2.6%) patients died within 30 days of treatment. Rates of radiological complete or partial response for local and metastatic disease were 90% and 66%, respectively. 24% patients had radiological disease progression of metastatic disease. Median overall survival for patients with unresectable metastatic disease at baseline was 23 months (95%CI: 19-28). 12 patients underwent radical surgery to both the rectum and liver and had an estimated 3-year overall survival rate of 62% (95%CI: 37-100). For those patients who did not proceed to rectal surgery, only 7% required palliative re-irradiation or surgery at a later date and all >20months from initial treatment.

CONCLUSIONS

In patients with unresectable metastatic disease, FOLFOX + CRT provides durable pelvic control for the majority without the need for additional local treatment. For patients with an advanced primary tumor and synchronous resectable liver-only metastases, FOLFOX + CRT can be considered a feasible and tolerable upfront treatment option.

How accurate are medical oncologists' impressions of management of metastatic colorectal cancer in Australia?

AIM

Current efforts to understand patient management in clinical practice are largely based on clinician surveys with uncertain reliability. The TRACC (Treatment of Recurrent and Advanced Colorectal Cancer) database is a multisite registry collecting comprehensive treatment and outcome data on consecutive metastatic colorectal cancer (mCRC) patients at multiple sites across Australia. This study aims to determine the accuracy of oncologists' impressions of real-word practice by comparing clinicians' estimates to data captured by TRACC.

METHODS

Nineteen medical oncologists from nine hospitals contributing data to TRACC completed a 34-question survey regarding their impression of the management and outcomes of mCRC at their own practice and other hospitals contributing to the database. Responses were then compared with TRACC data to determine how closely their impressions reflected actual practice.

RESULTS

Data on 1300 patients with mCRC were available. Median clinician estimated frequency of KRAS testing within 6 months of diagnosis was 80% (range: 20-100%); the TRACC documented rate was 43%. Clinicians generally overestimated the rates of first-line treatment, particularly in patients over 75 years. Estimate for bevacizumab in first line was 60% (35-80%) versus 49% in TRACC. Estimated rate for liver resection varied substantially (5-35%), and the estimated median (27%) was inconsistent with the TRACC rate (12%). Oncologists generally felt their practice was similar to other hospitals.

CONCLUSIONS

Oncologists' estimates of current clinical practice varied and were discordant with the TRACC database, often with a tendency to overestimate interventions. Clinician surveys alone do not reliably capture contemporary clinical practices in mCRC.

Small bowel adenocarcinoma treatment: A single centre experience

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Background: Small bowel adenocarcinoma (SBA) has a high mortality. Randomised controlled trials are not feasible due to its rarity, therefore there is no gold standard treatment approach. Surgical resection for early stage disease is the only potentially curative option. Systemic therapeutic options are generally extrapolated from oesophagogastric and colorectal chemotherapy regimens. Methods: This is a retrospective review of treatment and outcomes for SBA patients who attended Eastern Health between 1st January 2010 and 30thJune 2015. Approval was obtained from the Eastern Health Human Research and Ethics Committee. Results: Thirty-six patients with SBA were identified: 16 (44%) duodenal, 12 (33%) ampullary, 6 (17%) jejunal, 2 (6%) terminal ileum, 1 not specified. Median age was 72 and 25 (69%) were male. Stage at diagnosis was as follows: Stage 1 = 4 (11%), Stage 2 = 8 (22%), Stage 3 = 9 (25%) and Stage 4 = 10 (28%). Surgery with curative intent occurred in 19 patients (Whipple’s = 13, wide local excision = 6) of whom 6 received adjuvant (predominantly fluoropyrimidine-based) chemotherapy. One patient died from post-operative complications. At last follow-up, 8 patients remained in complete remission; 11 had relapsed; 3 were lost to follow-up. Three patients had died due to disease. Median relapse-free survival in the curative-intent group was 21.4 months. Median overall survival (OS) has not been reached. Sixteen patients were initially treated with palliative intent. Ten underwent palliative surgery (bypass = 7; resection = 3). Overall, 16 patients commenced palliative chemotherapy, including 8 from the curative-intent group post-relapse. The most commonly used regimen was oxaliplatin plus fluoropyrimidine. Best responses to chemotherapy were partial response = 5 (31%) and stable disease = 4 (25%). Six patients received second-line chemotherapy. Median progression-free survival on first-line chemotherapy was 4.8 months. Median OS was 9.4 months. Conclusions: SBA has a poor prognosis. Although 56% of advanced SBA patients had disease control using chemotherapy extrapolated from other gastrointestinal malignancies, responses were not durable.

Utilization of systemic therapy options in the routine treatment of metastatic colorectal cancer

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Background: In the treatment of metastatic colorectal cancer (mCRC), exposure to all three active cytotoxic agents; 5-fluorouracil/capecitabine (FP), irinotecan (Ir) and oxaliplatin (Ox), and the biologic agents, bevacizumab (Bev) and cetuximab and panitumumab (EGFR-I) improves outcomes. The current uptake of systemic agents for mCRC in a community setting in Australia is poorly described. Methods: The ACCORD database was interrogated to determine demographics, treatments and outcomes for all patients diagnosed with mCRC between 1/01/2011 and 1/01/2015 at 6 Melbourne centres (3 public and 3 private). Results: 865 patients were identified: median age was 68 years. 68% were ECOG 0-1, 60% had de novo metastatic disease. RAS status was known in 59%, of whom 48% were RAS wild-type (WT). At the time of analysis 69% of all patients had received systemic treatment with 51% receiving treatment second line and beyond; 65% RAS WT, 57% RASm, 16% RAS-Unk. See Table. Metastasectomy was performed in 29% of patients of whom 38% remain disease-free. With a median follow-up of 31.3 months 46% of patients remain alive. The median overall survival was 25 months for all patients(unresected;17.6 months, resected: not reached). Conclusions: A high proportion of patients receiving routine clinical care in the community setting do not receive any systemic therapy and few patients receive all available active agents. Despite this, the overall survival of patients with mCRC in this community-based cohort was 25 months and in-line with clinical trial data. [Table: see text]

Impact of Primary Tumor Site on Bevacizumab Efficacy in Metastatic Colorectal Cancer

BACKGROUND

With an ever-increasing focus on personalized medicine, all factors known to affect treatment response need to be considered when defining optimal therapy for individual patients. While the prognostic impact of primary tumor site on colorectal cancer (CRC) outcomes is established, emerging data suggest potential differences in response to biologic therapies. We studied the impact of tumor site on bevacizumab efficacy in patients with metastatic CRC.

PATIENTS AND METHODS

We analyzed data of patients in an Australian prospective multicenter metastatic CRC (mCRC) registry who received first-line chemotherapy. Tumor site was defined as right colon, cecum to transverse; left colon, splenic flexure to rectosigmoid; and rectum. Kaplan-Meier and Cox models were used for survival analyses.

RESULTS

Of 926 patients, 297 had right colon, 354 left colon, and 275 rectum primary disease. Median age was 68.6, 65.9, and 63.3 years, respectively (P = .001). Right colon disease was significantly associated with intraperitoneal spread (P < .0001), while left colon and rectum disease preferentially metastasized to the liver and lungs, respectively (P < .0001 in both settings). A total of 636 patients (68.7%) received bevacizumab. Progression-free survival was superior for bevacizumab-treated patients in all groups but appeared greatest in right colon disease (hazard ratio, 0.46; 95% confidence interval, 0.36-0.60; P ≤ .001). Overall survival was longest in patients with disease of the rectum, followed by left colon and right colon (median, 26.2, 23.6, and 18.2 months, respectively; P = .0004).

CONCLUSION

Tumor site appears to be prognostic in mCRC, with rectum and right colon disease associated with the best and worst outcomes, respectively. Patients who received bevacizumab in addition to chemotherapy had superior outcomes, with the effect appearing greatest in patients with right colon disease.

A phase 1b study of the anti-cancer stem cell agent demcizumab (DEM) and gemcitabine (GEM) +/- nab-paclitaxel in patients with pancreatic cancer

341

Background: Delta-like ligand 4 (DLL4) activates the Notch pathway. DEM is a humanized anti-DLL4 antibody that inhibits tumor growth & decreases cancer stem cell frequency in human tumor xenograft models. DEM also has an antiangiogenic effect & synergistic activity when combined with GEM & nab-paclitaxel in pt derived xenograft models of pancreatic cancer. Methods: Pts with 1st line pancreatic cancer were enrolled. Pts in cohorts 1-3 received DEM (2.5 every 2 or 4 wks or 5 mg/kg every 4 wks including 3 truncated pts) & GEM 1000 mg/m2 7 of 8 wks, then 3 of 4 wks. Pts in cohorts 4, 5, 6 & 7 received truncated DEM (2.5, 3.5 or 5 mg/kg every 2 wks through Day 70) & nab-paclitaxel 125 mg/m2 + gemcitabine 1000 mg/m2 3 of 4 wks. The primary objective was to determine the MTD. Other objectives were safety, efficacy, immunogenicity, PK & biomarkers. Results: Fifty-six pts were enrolled; 8, 8, 8, 6, 8, 9 & 9 pts received 2.5 mg/kg every 2 wks, 2.5 mg/kg every 4 wks, 5 mg/kg every 4 wks, 2.5 mg/kg every 2 wks (truncated), 5 mg/kg every 2 wks (truncated), 3.5 mg/kg every 2 wks (truncated) & 3.5 mg/kg every 2 wks (truncated), respectively. Related AEs in > 20% of pts were fatigue (36%), nausea (32%), vomiting (23%), hypertension (21%) & diarrhea (20%). Hypertension was managed with anti-hypertensives. Increased BNP is an early indicator of the cardiac effects of DEM & mildly elevated values were used to initiate a cardioprotective ACE inhibitor or carvedilol. Two pts who received DEM continuously developed reversible pulmonary hypertension & 1 of these pts developed heart failure. As a result, DEM was limited to 70 days in cohorts 4, 5, 6 & 7. In cohorts 1-3, 4 of 16 (25%) pts had a PR. In cohorts 4, 5, 6 & 7, 14 of 28 (50%) pts had a PR & 11 had SD. The truncated DEM pts had a median PFS of 9.0 mos (95% CI: 3.7 mos-NR) & a median survival of 10.1 mos (95% CI: 6.5-16.2 mos), respectively. Conclusions: This therapy was generally well tolerated with fatigue, nausea & vomiting being the most common related AEs. Truncated DEM dosing (i.e., limited to 70 days) avoided clinically significant cardiopulmonary toxicity. Encouraging clinical activity was observed. Biomarker analysis showed modulation of the Notch pathway. Final data will be presented. Clinical trial information: NCT01189929.

Effect of baseline carbohydrate antigen 19-9 (CA19-9) level on overall survival (OS) in NAPOLI-1 trial: A phase III study of MM-398 (nal-IRI), with or without 5-fluorouracil and leucovorin (5-FU/LV), versus 5-FU/LV in metastatic pancreatic cancer (mPAC) previously treated with gemcitabine-based therapy

425

Background: CA19-9 has been shown to correlate with response to therapy and OS in patients with mPAC. NAPOLI-1, a randomized phase 3 study evaluated nal-IRI, a nanoliposomal formulation of irinotecan, with or without 5-FU/LV vs 5-FU/LV in patients with mPAC previously treated with gemcitabine-based therapy. Nal-IRI+5-FU/LV significantly improved OS (primary endpoint) vs 5-FU/LV (6.1 mo vs 4.2 mo; unstratified hazard ratio [HR] = 0.67; P = 0.012). CA19-9 response (≥50% decline from baseline) was superior with nal-IRI+5FU/LV compared with 5-FU/LV (29% vs 9%; P=0.0006). Nal-IRI alone did not show a statistical improvement in survival. Methods: Patients with a recorded baseline CA19-9 measurement were divided into quartiles to evaluate the treatment effect pattern of CA19-9 from nal-IRI+5-FU/LV and 5-FU/LV arms. Quartile ranges were based on 404 available CA19-9 values from randomized patients (N=417). Unstratified Cox proportional hazards regression was used to estimate HRs and corresponding 95% CIs. Effect of baseline CA19-9 on time to response, progression-free survival, and response will be presented. Results: Of patients randomized to receive nal-IRI+5-FU/LV (n = 117) or 5-FU/LV enrolled contemporaneously (n = 119), 218 received study drug and had a baseline CA19-9 measurement. Results show a greater treatment effect on OS with higher CA19-9 level relative to 5-FU/LV. Conclusions: In patients with mPAC previously treated with gemcitabine-based therapy, nal-IRI+5-FU/LV significantly improved OS supported by progression free survival and objective response rate. The CA19-9 serum level can provide important information with regards to overall survival. Clinical trial information: NCT01494506. [Table: see text]

Primary Tumor Resection and Overall Survival in Patients With Metastatic Colorectal Cancer Treated With Palliative Intent

BACKGROUND

The survival impact of primary tumor resection in patients with metastatic colorectal cancer (mCRC) treated with palliative intent remains uncertain. In the absence of randomized data, the objectives of the present study were to examine the effect of primary tumor resection (PTR) and major prognostic variables on overall survival (OS) of patients with de novo mCRC.

PATIENTS AND METHODS

Consecutive patients from the Australian 'Treatment of Recurrent and Advanced Colorectal Cancer' registry were examined from June 2009 to March 2015. Univariate and multivariate Cox proportional hazards regression analyses were used to identify associations between multiple patient or clinical variables and OS. Patients with metachronous mCRC were excluded from the analyses.

RESULTS

A total of 690 patients de novo and 373 metachronous mCRC patients treated with palliative intent were identified. The median follow-up period was 30 months. The median age of de novo patients was 66 years; 57% were male; 77% had an Eastern Cooperative Oncology Group performance status of 0 to 1; and 76% had a colon primary. A total of 216 de novo mCRC patients treated with palliative intent underwent PTR at diagnosis and were more likely to have a colon primary (odds ratio [OR], 15.4), a lower carcinoembryonic antigen level (OR, 2.08), and peritoneal involvement (OR, 2.58; P < .001). On multivariate analysis, PTR at diagnosis in de novo patients was not associated with significantly improved OS (hazard ratio [HR], 0.82; 99% confidence interval [CI], 0.62-1.09; P = .068). PTR at diagnosis did not correlate with outcome in de novo patients with a colon primary (HR, 0.74; 99% CI, 0.54-1.01; P = .014) or a rectal primary (HR, 0.81; 99% CI, 0.27-2.44; P = .621).

CONCLUSION

For de novo mCRC patients treated with palliative intent, PTR at diagnosis does not significantly improve OS when adjusting for known major prognostic factors. The outcomes of randomized trials examining the survival impact of PTR are awaited.

Phase II trial evaluating the feasibility of interdigitating folfox with chemoradiotherapy in locally advanced and metastatic rectal cancer

BACKGROUND

Patients (pts) with metastatic rectal cancer and symptomatic primary, require local and systemic control. Chemotherapy used during chemoradiotherapy (CRT) is adequate for radiosensitisation, but suboptimal for systemic control. The aim of this phase II study was to assess tolerability, local/systemic benefits, of a novel regimen delivering interdigitating intensive chemotherapy with radical CRT.

METHODS

Eligible pts had untreated synchronous symptomatic primary/metastatic rectal cancer. A total of 12 weeks of treatment with split-course pelvic CRT (total 50.4 Gy with concurrent oxaliplatin and 5-FU infusion) alternating with FOLFOX chemotherapy. All pts staged with CT, MRI and FDG-PET pre and post treatment.

RESULTS

Twenty-six pts were treated. Rectal primary MRI stage: T3 81% and T4 15%. Liver metastases in 81%. Twenty-four pts (92%) completed the 12-week regimen. All patients received planned RT dose, and for both agents over 88% of patients achieved a relative dose intensity of >75%. Grade 3 toxicities: neutropenia 23%, diarrhoea 15%, and radiation skin reaction 12%. Grade 4 toxicity: neutropenia 15%. FDG-PET metabolic response rate for rectal primary 96%, and for metastatic disease 60%.

CONCLUSIONS

Delivery of interdigitating chemotherapy with radical CRT was feasible to treat both primary and metastatic rectal cancer. High completion and response rates were encouraging.

A phase 1b study of the anticancer stem cell agent demcizumab (DEM) and gemcitabine (GEM) with or without paclitaxel protein bound particles (nab-paclitaxel) in patients with pancreatic cancer

279

Background: Delta-like ligand 4 (DLL4) is a ligand that activates the Notch pathway. DEM is a humanized IgG2anti-DLL4 antibody that inhibits tumor growth and decreases cancer stem cell (CSC) frequency in minimally passaged human xenograft models. In addition, DEM has been shown to have an antiangiogenic effect and showed synergistic activity when combined with GEM and nab-paclitaxel in human pancreatic tumor-derived xenograft models. Methods: Pts with 1st line stage pancreatic cancer received DEM (2.5 every 2 or 4 wks or 5 mg/kg every 4 wks) and GEM 1000 mg/m27 of 8 wks, then 3 of every 4 wks. The primary objective was to determine the MTD of DEM. Other objectives were safety, efficacy, immunogenicity, PK and biomarkers of Notch signaling and CSCs. Results: Twenty four pts were enrolled; 8 received 2.5 mg/kg every 2 wks, 8 received 2.5 mg/kg every 4 wks & 8 received 5 mg/kg every 4 wks of DEM. Three (12.5%) and 21 (87.5%) pts had stage III and IV disease, respectively. Related AEs (all grades) in > 15% of pts were: fatigue (29%), hypertension (29%), vomiting (29%), nausea (25%), thrombocytopenia (21%) and decreased appetite (21%). The hypertension was managed with oral anti-hypertensives. Increased BNP values appear to be an early indicator of the cardiac effects of DEM and mildly elevated values are being used to initiate cardioprotective therapy with an ACE inhibitor or carvedilol. One pt who received 5 mg/kg developed reversible pulmonary hypertension and heart failure on study day 143. As a result, the duration of DEM will be limited to 70 days in subsequent cohorts. Four of 16 (25%) pts had a RECIST partial response and 7 had stable disease. The median PFS for the 5 mg/kg cohort was 5.9 months. The PK and immunogenicity data will also be presented. Conclusions: DEM plus GEM were generally well tolerated with fatigue, hypertension, and vomiting being the most common drug related AEs. Encouraging early clinical activity was observed. The duration of DEM is being limited to 70 days and nab-paclitaxel is also being given in subsequent cohorts. The first cohort of pts receiving GEM, nab-paclitaxel, and DEM has been enrolled and > 100 days of follow-up on these pts will be presented. Clinical trial information: NCT01189929.

Abstract B78: A Phase Ib study of demcizumab (DEM, anti-DLL4) with gemcitabine (GEM) in patients with first line locally advanced or metastatic pancreatic cancer

Background: Delta-like ligand 4 (DLL4) is a ligand that activates the Notch pathway which is important for cancer stem cell (CSC) survival. DEM is a humanized IgG2 anti-DLL4 antibody that has been shown to inhibit tumor growth and decrease CSC frequency in minimally passaged human xenograft models. In addition, inhibition of DLL4 has also been shown in preclinical studies to cause dysfunctional sprouting of new vessels resulting in an antiangiogenic effect. DEM also showed synergistic activity when combined with GEM in human pancreatic tumor-derived xenograft models.

Material and Methods: Patients with first line stage III or IV pancreatic cancer received DEM (2.5 every 2 or 4 wks or 5 mg/kg every 4 wks) and GEM 1000 mg/m2 7 of the 1st 8 wks and then 3 of every 4 wks until disease progression. The primary objective was to determine the maximum tolerated dose of DEM. Other objectives included: safety, efficacy, immunogenicity, pharmacokinetic, and biomarkers of Notch signaling and CSCs.

Results: Twenty four patients were enrolled; 8 pts received 2.5 mg/kg every 2 wks, 8 received 2.5 mg/kg every 4 wks and 8 received 5 mg/kg every 4 wks of DEM. The median age was 65.5 yrs. Three (12.5%) and 21 (87.5%) patients had stage III and IV disease, respectively. Seven, 16 and 1 patients were ECOG performance status 0, 1, and 2, respectively. Related adverse events (all grades) in ≥10% of patients included: fatigue (29%), hypertension (29%), vomiting (29%), nausea (25%), thrombocytopenia (21%), decreased appetite (21%), increased B-type natriuretic peptide (BNP) (13%), anemia (13%), peripheral edema (13%), pulmonary hypertension (13%), dizziness (13%) and rash (13%). The hypertension was successfully managed with oral anti-hypertensives. Increased BNP values appear to be an early indicator of the cardiac effects of DEM and mildly elevated values are being used to initiate cardioprotective therapy with an ACE inhibitor or carvedilol. One patient who received 5 mg/kg developed reversible pulmonary hypertension and heart failure on study day 143. As a result, the duration of DEM will be limited to 70 days in subsequent cohorts and paclitaxel protein-bound particles will also be added to the regimen. Four of 16 (25%) evaluable patients had a RECIST partial response and 7 had stable disease. The median progression free survival for the 5 mg/kg cohort was 5.9 months. The pharmacokinetic and immunogenicity samples are being analyzed and these data will be presented.

Conclusion: DEM plus GEM was generally well tolerated with fatigue, hypertension and vomiting being the most common drug related adverse events. The duration of demcizumab therapy is being limited to 70 days in subsequent cohorts due to cardiopulmonary toxicity which was observed following more prolonged administration. Encouraging early clinical activity has been observed. Subsequent cohorts will include paclitaxel protein-bound particles. Enrollment is ongoing and updated results will be presented.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B78.

Citation Format: Antonio Cubillo, Michael Jameson, Enrique Grande, Francis Parnis, Peter Grimison, Prasad Cooray, Mark Jeffery, Robert Stagg, Jakob Dupont, Niall Tebbutt. A Phase Ib study of demcizumab (DEM, anti-DLL4) with gemcitabine (GEM) in patients with first line locally advanced or metastatic pancreatic cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B78.

Final results of AGITG ATTAX3 study: Randomized phase II study of weekly docetaxel (T), cisplatin, and fluoropyrimidine (F) with or without panitumumab (P) in advanced esophagogastric (OG) cancer

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Background: This randomized phase II study evaluated the efficacy and safety of P, a fully human mAb against the epidermal growth factor receptor combined with T-based chemotherapy in advanced OG cancer. Methods: Eligible pts had histologically confirmed metastatic OG cancer (adeno-carcinoma and squamous cell carcinoma) were ≥18 years of age, PS 0-2, with adequate renal, haematologic and liver function with measurable disease. All pts provided informed consent. Selection was not based on kras determination. Pts received T 30mg/m2 d1,8, C 60mg/m2 d1 and F; investigator choice of 5FU infusion 160mg/m2/d or capecitabine 500mg/m2bd continuous ±P 9 mg/kg d1 q3w. Treatment was administered for 8 cycles or until PD. The primary endpoint was response rate according to RECIST (1.1) assessed q6w. Planned enrolment target was 100 pts. Stratification variables included histology, PS and choice of F. Results: From April 2010 to November 2011, 77 pts were enrolled from 15 institutions. A safety alert from the REAL3 study (also involving P in OG cancer) prompted an unplanned review of data from ATTAX3 by the IDMC. The IDMC found no evidence of adverse outcomes associated with P, but as it did not appear that P would significantly improve efficacy, they recommended cessation of the study to new enrolment. Previously enrolled pts were treated and followed according to protocol. Median follow up is 24m. Treatment arms were well balanced; median age 59, 64y, male 77%, 87%, PS0-1 95%,90%, adenocarcinoma 90%,90%, capecitabine 67%, 66% for TCF/TCF-P, respectively. Common grade 3/4 toxicities include infection 18%,24%, febrile neutropenia 10%, 5%, anorexia 10%, 24%, nausea 18%,30%, stomatitis 3%,5%, diarrhoea 15%,24% , acneiform rash 0%, 8%, fatigue 18%, 30%, hypomagnesemia 10%, 16% for TCF/TCF-P. Efficacy outcomes are summarized in Table. Conclusions: The addition of P to T-based chemotherapy in advanced OG cancer did not improve efficacy and was associated with an increase in some toxicities. Clinical trial information: ACTRN12609000109202. [Table: see text]

Neoadjuvant therapy with nanoparticle albumin-bound (nab)-paclitaxel to enhance the resectability of locally advanced pancreatic cancer (LAPC)

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Background: Resection offers the only probability of cure for pancreatic adenocarcinoma but only a minority have resectable disease at diagnosis. Effective neo-adjuvant therapy for LAPC could down-size the tumor rendering it resectable. Neo-adjuvant therapy may retard cancer dissemination thought to occur early in pancreatic cancer. The aim of this study was to retrospectively evaluate if neo-adjuvant treatment with nab-paclitaxel in patients with LAPC could result in tumor down-sizing to allow resection and improve outcomes. Methods: Data was collected from the medical records of pancreatic cancer patients who presented to two clinics from 06/2009 to 12/2011 and were treated with nab-paclitaxel (n = 63). Resectability was assessed by review of imaging by the radiologist and the treating surgeon. Twenty three of 63 patients had LAPC and 40/63 had stage IV disease. Of the LAPC patients, 8/23 (35%) were classified as borderline resectable (BR) and 15/23 (65%) were classified as unresectable (UR). Patients received nab-paclitaxel (100-125 mg/m2 D1,8,15) in combination with gemcitabine or carboplatin. The BR/UR patients (n=23) received a median 5 cycles of chemotherapy. They were re-evaluated for suitability for surgical resection. Results: Following neo-adjuvant treatment, 16/23 (69%) had a radiological PR and 17/23 (74%) had a major biochemical response (defined as >70% decline in Ca19.9 level). A total of 6/23 patients (26%) were then able to undergo surgical resection, with resections planned for further 2/23 (8%) patients.Of the 6 resected patients, 4 had R0 resections and 2 had R1 resection. After a median follow up of 18 months, all 6 resected patients are alive and 4 of them remain free of cancer recurrence. The median survival for patients who remained unresectable (15/23) was 9 months. The median survival for converted patients (6/23) has not yet reached. Conclusions: These results suggest that a subgroup of patients with LAPC could be converted to a resectable stage with the use of nab-paclitaxel as neo-adjuvant therapy. Such converted patients may enjoy durable improved outcomes and this approach warrants further investigation in a phase II clinical trial.

Phase II trial evaluating a 12-week regimen of interdigitating FOLFOX chemotherapy plus pelvic chemoradiation for the simultaneous treatment of primary and metastatic rectal cancer

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Background: Current chemotherapy regimens used during chemoradiation (CRT) are adequate for radiosensitization but suboptimal for systemic control. The aim of this study was to assess tolerability, and local/systemic benefits of new regimen delivering intensive chemotherapy and radical radiotherapy in an interdigitating manner. Methods: Phase II prospective study for patients (pts) with untreated simultaneous symptomatic primary and metastatic rectal cancer. The treatment regimen: 12 weeks long. FOLFOX chemotherapy (oxaliplatin 100mg/m2, leucovorin 200mg/m2, 5-FU 400mg/m2 bolus, all day 1, and 5FU continuous infusion [CI] 2.4 g/m2/46 hours) was given in weeks 1, 6, and 11. Pelvic CRT: 25.2 Gy in 3 weeks, 1.8 Gy/fr, with concurrent oxaliplatin 85mg/m2 day 1 and 5-FU CI 200mg/m2/day given in weeks 3-5, and 8-10. Pts received, in 12 weeks, 3 courses of FOLFOX and pelvic radiation 50.4 Gy with concurrent oxaliplatin/5-FU. All pt were staged with CT, MRI and FDG-PET before and post-treatment. Results: 26 pts treated. The mean age was 61 years, 69% male. Rectal primary MRI stage was T2 4%, T3 81% and T4 15%. Liver and lung metastases were present in 81%, and 35% of pts, respectively: 38% of patients had more than one site of metastatic disease. 24 pts (92%) completed the 12-week treatment regimen. All pts received the planned radiation dose. 65% of pts received the planned number of oxaliplatin courses with 88% of pts receiving at least 75% of the protocol oxaliplatin dose. In this 12-week period, grade 3 toxicities were neutropenia 23%, diarrhoea 15%, and radiation perineal skin reaction 12%. Only grade 4 toxicity was neutropenia: 15%. PET metabolic response (CR+PR) rate for rectal primary was 96%. Overall PET metabolic response rate for metastatic disease was 60% (CR rate 16%). Conclusions: It is thus feasible to deliver intensive chemotherapy and radical radiotherapy in an interdigitating manner to treat both primary and metastatic rectal cancer simultaneously. High completion and response rates are encouraging. This regimen is the subject of a current phase II neoadjuvant trial for resectable rectal cancer (TROG 09.01).

Effect of nab-paclitaxel combination chemotherapy on response and survival in pancreatic cancer

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Background: Pancreatic cancer has traditionally had few effective chemotherapy options. Recent discovery of the over-expression of SPARC (Secreted Protein Acidic Rich in Cysteine) on the majority of pancreatic cancers suggests possible utility of nab-paclitaxel, (a novel albumin-bound form of paclitaxel) as a treatment option. A small prospective study (ASCO 2009) supported this theory. We sought to retrospectively evaluate the treatment efficacy of nab-paclitaxel with gemcitabine or carboplatin in patients with pancreatic cancer to assess concordance with the previous small prospective study. Methods: Data was collected retrospectively from the medical records of pancreatic cancer patients who presented to the private clinic of two treating oncologists (n = 63) from June 2009 to December 2011 and were treated with nab- paclitaxel in combination with either gemcitabine or carboplatin. Patients were assessed on the basis of changes in serum tumour marker (CA19-9, CEA or CA15-3) and changes in tumour size on radiological imaging. Results: 39 (70%) patients had a biochemical response with a greater than 20% drop in tumour markers. Of these, 30 (94%) showed greater than 70% drop with all responders showing reduction in markers within 6 weeks of starting. The number of patients with biochemically defined disease control was 48 (86%). 36 patients were deceased by the end of the series with median overall survival being 12.9 months. The median survival time from starting nab-paclitaxel for these patients was 7.9 months. Very long survival times (up to 28.1 months following commencement nab-paclitaxel) were also observed in 2 patients at the time of data analysis. The overall disease control rate radiologically was 76.79% (43 of 56). Of the 43 responders, 10 were complete responders, 22 showed partial radiological response and 11 had stable disease. Conclusions: This retrospective case series demonstrates a near doubling of overall median survival time and also an improved response rate in patients on nab-paclitaxel treatment as compared to historical data of other treatment options for pancreatic carcinoma. It further supports Von Hoff’s data from ASCO 2010. Further prospective data is eagerly awaited.

Multiple periungual pyogenic granulomas following systemic 5-fluorouracil

A 65-year-old man presented with a 7-month history of eight bleeding periungual lesions on both feet. The clinical diagnosis of multiple pyogenic granulomas was confirmed by histological examination. Historically, the pyogenic granulomas appeared 3 months after commencing 5-fluorouracil chemotherapy for rectal carcinoma, suggesting a possible causative relationship. Chemotherapy was ceased by the supervising oncologist. Resolution occurred after two lesions had been treated with curettage and diathermy, and the remaining lesions with occlusive dressings over Kenacomb ointment (triamcinolone acetonide 0.1%, neomycin sulphate 0.25%, gramicidin 0.025%, nystatin 100,000 U/g) topically twice daily for a period of 3 months.

Calpain cleavage of focal adhesion proteins regulates the cytoskeletal attachment of integrin alphaIIbbeta3 (platelet glycoprotein IIb/IIIa) and the cellular retraction of fibrin clots

The intracellular thiol protease calpain catalyzes the limited proteolysis of various focal adhesion structural proteins and signaling enzymes in adherent cells. In human platelets, calpain activation is dependent on fibrinogen binding to integrin alphaIIbbeta3 and subsequent platelet aggregation, suggesting a potential role for this protease in the regulation of postaggregation responses. In this study, we have examined the effects of calpain activation on several postaggregation events in human platelets, including the cytoskeletal attachment of integrin alphaIIbbeta3, the tyrosine phosphorylation of cytoskeletal proteins, and the cellular retraction of fibrin clots. We demonstrate that calpain activation in either washed platelets or platelet-rich plasma is associated with a marked reduction in platelet-mediated fibrin clot retraction. This relaxation of clot retraction was observed in both thrombin and ionophore A23187-stimulated platelets. Calcium dose-response studies (extracellular calcium concentrations between 0.1 microM and 1 M) revealed a strong correlation between calpain activation and relaxed clot retraction. Furthermore, pretreating platelets with the calpain inhibitors calpeptin and calpain inhibitor I prevented the calpain-mediated reduction in clot retraction. Relaxed fibrin clot retraction was associated with the cleavage of several platelet focal adhesion structural proteins and signaling enzymes, resulting in the dissociation of talin, pp60(c-)src, and integrin alphaIIbbeta3 from the contractile cytoskeleton and the tyrosine dephosphorylation of multiple cytoskeletal proteins. These studies suggest an important role for calpain in the regulation of multiple postaggregation events in human platelets. The ability of calpain to inhibit clot retraction is likely to be due to the cleavage of both structural and signaling proteins involved in modulating integrin-cytoskeletal interactions.

Non-receptor protein tyrosine kinases and phosphatases in human platelets

There is now a large and rapidly growing body of information on the different types of non-receptor tyrosine kinases and phosphatases present within platelets. These enzymes appear to play a critical role in co-ordinating, integrating and amplifying signals from multiple cell surface receptors. Despite considerable progress in this area of research over the last decade, a coherent understanding of how these enzymes fit into the complex communication networks of platelets remains elusive. The challenge ahead will be to define the molecular interactions and hierarchies between tyrosine kinases, phosphatases and other platelet signalling enzymes, and to pinpoint the key phosphorylation reactions required for the induction of specific platelet responses.

Focal adhesion kinase (pp125FAK) cleavage and regulation by calpain

Focal adhesion kinase (125 kDa form; pp125FAK) is a widely expressed non-receptor tyrosine kinase that is implicated in integrin-mediated signal transduction. We have identified a novel means of pp 125FAK regulation in human platelets, in which this kinase undergoes sequential proteolytic modification from the native 125 kDa form to 90, 45 and 40 kDa fragments in thrombin-, collagen- and ionophore A23187-stimulated platelets. The proteolysis of pp125FAK was prevented by pretreating platelets with the calpain inhibitors calpeptin or calpain inhibitor-1, and was reproduced in vitro by incubating immunoprecipitated pp125FAK with purified calpain. Proteolysis of pp125FAK resulted in a dramatic reduction in its autokinase activity and led to its dissociation from the cytoskeletal fraction of platelets. These studies define a novel signal-terminating role for calpain, wherein proteolytic modification of pp125FAK attenuates its autokinase activity and induces its subcellular relocation within the cell.