Abstract B103: Intralesional administration of CTLA-4 blocking monoclonal antibodies as a means to optimize bladder cancer therapy

CTLA-4 blockade as well as CD40 agonistic therapy comes with adverse events when administrated systemically to patients. Whereas anti-CD40 therapy is associated with both cytokine release and liver toxicity, CTLA-4 blockade leads to auto-immune manifestations. Cytokine release affects the maximum tolerated dose (MTD) for anti-CD40, thereby hampering anti-tumor responses. Whereas patients with localized bladder cancer respond to immunotherapy in the form of BCG, they suffer high relapse frequencies and toxicity. Patients with a more advanced disease have a poor prognosis due to relapses, and not all patients are fit to undergo radical cystectomy, mainly due to age, underlying diseases and health status. There is also a high tumor recurrence (50% of cystectomy patients relapse with local or metastatic tumor growth). We believe these patients could benefit from local immunotherapy similar to BCG instillations, but focusing on strengthening the adaptive immune response rather than the innate. In solid cancer where an accessible tumor lesion is available, monoclonal antibody therapies targeting our immune cells can be administrated intralesionally (1). In a preclinical bladder cancer model we show that both anti-CD40 and anti-CTLA-4 therapy can be used in a lower dose with a peritumoral injection route (2, 3 and current work). Local anti-CD40 therapy partly limits systemic spread of the antibody and the efficacy is dependent on the presence of tumor antigens at the site of the location. CD8+ T cells are the main effectors cells causing tumor regression (3). Herein we initially assessed standard orthotopic instillation of CTLA-4 directed antibody therapy, but drug uptake was poor despite pre-conditioning with clorpactin. As an alternative we slightly modified our existing MB49 syngeneic tumor model based (by injecting tumor cells into the submucosal space of the anterior bladder wall), and made use of ultrasound-guided intratumoral anti-CTLA-4 antibody treatment. The results show tumor regression followed by a more than 10-fold reduction in systemic antibody levels as compared to intravenous administration, in line with the compartmentally restrained nature of the bladder. In addition, local anti-CTLA-4 therapy, when complemented by systemic anti-PD1 therapy for subcutaneously growing tumors, demonstrated CR in 7/8 animals, superior to each therapy alone. Our results demonstrate that local anti-CTLA-4 antibody therapy is equally effective as systemic administration, but reduces systemic antibody levels and that its combination with anti-PD1 therapy displays superior outcome. The clinical use of spasm-relieving injections in the bladder illustrates the feasibility to perform injections in clinical routine, and intralesional injections of a check-point inhibitor prior to surgery could boost the adaptive immune response and decrease relapse frequencies without the risk of adverse events delaying a planned surgery. 1. NCT02379741 (clinicaltrials.gov June 2016) 2. Sandin et al. Cancer Immunol Res. 2014 Jan;2(1) 3. Mangsbo et al. Clin Cancer Res. 2015 Mar 1;21(5)

Citation Format: Luuk van Hooren, Linda Sandin, Igor Moskalev, Peter Ellmark, Anna Dimberg, Peter Black, Thomas H. Tötterman, Sara M. Mangsbo. Intralesional administration of CTLA-4 blocking monoclonal antibodies as a means to optimize bladder cancer therapy [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B103.

Emerging role of checkpoint inhibition in localized bladder cancer

OBJECTIVE

Checkpoint inhibitors have rapidly become a standard treatment option for metastatic urothelial carcinoma. A wave of enthusiasm for these drugs has pushed them also into the setting of localized bladder cancer, including both non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive disease bladder cancer (MIBC). Here, we aimed to review the emerging role of checkpoint inhibition in localized bladder cancer.

METHODS

We reviewed the current treatment landscape for both NMIBC and MIBC and established a significant unmet clinical need for novel therapies. We have compiled the evidence that supports the investigation of checkpoint blockade in localized bladder cancer and have reviewed the corresponding clinical trial׳s landscape.

RESULTS

The success of checkpoint inhibitors in metastatic bladder cancer offers the most compelling rationale for testing checkpoint blockade in localized disease. The established benefit of intravesical Bacillus Calmette-Guérin provides precedent for immune therapy in bladder cancer. Immune dysfunction has been described in bladder cancer, and we know that checkpoint molecules are expressed in these tumors. Furthermore, the high neoantigen burden of bladder cancer and results from preclinical studies suggest that checkpoint blockade deserves testing in earlier stage disease. Multiple trials are either planned or underway in almost all bladder cancer disease states.

CONCLUSION

Ongoing trials would determine in the next several years whether checkpoint inhibitors can have a similar effect in localized disease as they have had in metastatic bladder cancer. They would also determine if patients with earlier disease would tolerate the toxicity of systemic therapy. The future holds promise for predictive biomarkers to guide individualized use of these agents and for effective combination therapies to overcome resistances.

Enumerating pelvic recurrence following radical cystectomy for bladder cancer: A Canadian multi-institutional study

INTRODUCTION

We aimed to enumerate the rate of pelvic recurrence following radical cystectomy at university-affiliated hospitals in Canada.

METHODS

Canadian, university-affiliated hospitals were invited to participate. They were asked to identify the first 10 consecutive patients undergoing radical cystectomy starting January 1, 2005, who had urothelial carcinoma stages pT3/T4 N0-2 M0. The first 10 consecutive cases starting January 1, 2005 who met these criteria were the patients submitted by that institution with information regarding tumour stage, age, number of nodes removed, and last known clinical status in regard to recurrence and patterns of failure.

RESULTS

Of the 111 patients, 80% had pT3 and 20% pT4 disease, with 62% being node-negative, 14% pN1, and 27% pN2; 57% had 10 or more nodes removed. Cumulative incidence of pelvic relapse was 40% among the entire group.

CONCLUSIONS

This review demonstrates a high rate of pelvic tumour recurrence following radical cystectomy for pT3/T4 urothelial cancer.

Effect of smoking status on the efficacy of the SMART regimen in high risk asthma

BACKGROUND AND OBJECTIVE

The optimal management of people with asthma with a significant smoking history is uncertain. The aim of this study was to determine whether the efficacy/safety profile of single combination inhaled corticosteroid (ICS)/long acting beta-agonist (LABA) inhaler maintenance and reliever therapy is influenced by smoking status.

METHODS

We undertook secondary analyses from an open-label 24-week randomized study of 303 high risk adult asthma patients randomized to budesonide/formoterol 200/6-µg-metred dose inhaler for maintenance (two actuations twice daily) and either budesonide/formoterol 200/6-µg-metred dose inhaler one actuation ('single ICS/LABA maintenance and reliever therapy (SMART)' regimen) or salbutamol 100 µg 1-2 actuations for symptom relief ('Standard' regimen). Smoking status was classified in to three groups, as 'current', 'ex' or 'never', and a smoking/treatment interaction term tested for each outcome variable. The primary outcome variable was number of participants with at least one severe exacerbation.

RESULTS

There were 59 current, 97 ex and 147 never smokers included in the analyses. The smoking status/treatment interaction term was not statistically significant for any of the outcome measures. With adjustment for smoking status, the number of participants with severe exacerbations was lower with the SMART regimen (OR 0.45, 95% CI: 0.26-0.77, P = 0.004; P value for interaction between smoking status and treatment 0.29).

CONCLUSION

We conclude that the favourable safety/efficacy profile of the SMART regimen applies to patients with high risk asthma, irrespective of smoking status.

Recommendations for the improvement of bladder cancer quality of care in Canada: A consensus document reviewed and endorsed by Bladder Cancer Canada (BCC), Canadian Urologic Oncology Group (CUOG), and Canadian Urological Association (CUA), December 2015

This initiative was undertaken in response to concerns regarding the variation in management and in outcomes of patients with bladder cancer throughout centres and geographical areas in Canada. Population-based data have also revealed that real-life survival is lower than expected based on data from clinical trials and/or academic centres. To address these perceived shortcomings and attempt to streamline and unify treatment approaches to bladder cancer in Canada, a multidisciplinary panel of expert clinicians was convened last fall for a two-day working group consensus meeting. The panelists included urologic oncologists, medical oncologists, radiation oncologists, patient representatives, a genitourinary pathologist, and an enterostomal therapy nurse. The following recommendations and summaries of supporting evidence represent the results of the presentations, debates, and discussions. Methodology

Malakoplakia of the prostate masquerading as locally advanced prostate cancer on mpMRI

A 66-year-old man was referred for urological evaluation for an abnormal digital rectal exam (cT2a, subtle nodule at left base, 121 cc prostate) and an elevated prostate specific antigen (PSA) of 8.0 ng/ml. Subsequent 12-core transrectal ultrasound (TRUS)-guided biopsy revealed Gleason 3+4 adenocarcinoma in seven of 12 cores, including all six cores on the right side and one core at the left apex. No extraprostatic extension was identified. Post-biopsy, the patient developed urinary retention requiring a catheter, as well as an Escherichia coli (E. coli) urinary tract infection (UTI) requiring hospitalization and intravenous antibiotics.