Chimeric Antigen Receptor-T Cells for Targeting Solid Tumors: Current Challenges and Existing Strategies

Chimeric antigen receptor-T cells (CAR-Ts) are an exciting new cancer treatment modality exemplified by the recent regulatory approval of two CD19-targeted CAR-T therapies for certain B cell malignancies. However, this success in the hematological setting has yet to translate to a significant level of objective clinical responses in the solid tumor setting. The reason for this lack of translation undoubtedly lies in the substantial challenges raised by solid tumors to all therapies, including CAR-T, that differ from B cell malignancies. For instance, intravenously infused CAR-Ts are likely to make rapid contact with cancerous B cells since both tend to reside in the same vascular compartments within the body. By contrast, solid cancers tend to form discrete tumor masses with an immune-suppressive tumor microenvironment composed of tumor cells and non-tumor stromal cells served by abnormal vasculature that restricts lymphocyte infiltration and suppresses immune function, expansion, and persistence. Moreover, the paucity of uniquely and homogeneously expressed tumor antigens and inherent plasticity of cancer cells provide major challenges to the specificity, potency, and overall effectiveness of CAR-T therapies. This review focuses on the major preclinical and clinical strategies currently being pursued to tackle these challenges in order to drive the success of CAR-T therapy against solid tumors.

Is the adjustable transobturator system ATOMS® useful for the treatment of male urinary incontinence in low to medium volume urological centers?

INTRODUCTION

Urinary incontinence (UI) is a complication of radical prostatectomy (RP) and transurethral resection of the prostate (TURP). The gold-standard treatment is the artificial urinary sphincter, however, new treatments have been investigated.

OBJECTIVE

To examine the outcome of an adjustable transobturator male system (ATOMS^®) in men with UI after prostatic surgery in a low to medium volume continence center.

MATERIALS AND METHODS

Twenty-five men with UI were implanted with ATOMS^® system between 2012 and 2014. The most common indication was UI after RP (92%), followed by UI after TURP (8%). Eleven patients (44%) had received adjuvant external beam radiotherapy (RT). Patients were considered to be 'dry' if they stopped wearing pads or needed just one protective pad per day; and improved if the daily number of pads used decreased by at least half. The Incontinence Quality of Life questionnaire (ICIQ-SF) was used, adding a verbal question about the satisfaction of the patient considering the outcome.

RESULTS

After a mean follow-up of 21.56 months, 64% were dry and 8% revealed a significant improvement. The success of the procedure was negatively correlated with the severity of the previous UI and with previous treatment with RT. Concerning patients satisfaction, 84% of the patients would repeat the procedure.

CONCLUSION

ATOMS^® offers good rates of cure and improvement of UI after prostatic surgery with a reasonable rate of minor complications. The results of this study, performed in a low to medium volume continence center, are comparable to the results achieved in high volume continence centers.

Benefit of cardiopoietic mesenchymal stem cell therapy on left ventricular remodelling: results from the Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) study

AIMS

Left ventricular (LV) reverse remodelling is an important marker of improved outcomes in patients with advanced heart failure (HF). We examined the impact of the intramyocardial administration of bone-marrow-derived, lineage-directed, autologous cardiopoietic mesenchymal stem cells (C3BS-CQR-1) on LV remodelling in patients with advanced HF enrolled in the CHART-1 study.

METHODS AND RESULTS

Patients (n=351) with symptomatic advanced HF secondary to ischaemic heart disease, and reduced LV ejection fraction (LVEF <35%) were randomized to receive C3BS-CQR-1 or a sham procedure. In a post hoc analysis we examined the effect of C3BS-CQR-1 on LV reverse remodelling within 1 year of the procedure and the influence of C3BS-CQR-1 dosing in the 271 patients treated as randomized. Delivery of C3BS-CQR-1 was associated with a progressive decrease in both LV end-diastolic volume (LVEDV) and end-systolic volume (LVESV) within 52 weeks after treatment. At 1 year, the LVEDV and LVESV of treated patients decreased by 17.0 mL and 12.8 mL greater than controls (P=0.006 and P=0.017, respectively). The effect on LVEDV was maintained after multivariable adjustment for baseline age, systolic blood pressure, LVEDV, LVEF and history of myocardial infarction. The largest reverse remodelling was evident in the patients receiving a moderate number of injections (<20).

CONCLUSION

In CHART-1, intramyocardial administration of cardiopoietic stem cells led to reverse remodelling as evidenced by significant progressive decreases in LVEDV and LVESV through the 52 weeks of follow-up. Further studies are needed to explore the dose response with regard to cell number and injected volume, and reverse remodelling.

Cardiopoietic cell therapy for advanced ischaemic heart failure: results at 39 weeks of the prospective, randomized, double blind, sham-controlled CHART-1 clinical trial

AIMS

Cardiopoietic cells, produced through cardiogenic conditioning of patients' mesenchymal stem cells, have shown preliminary efficacy. The Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial aimed to validate cardiopoiesis-based biotherapy in a larger heart failure cohort.

METHODS AND RESULTS

This multinational, randomized, double-blind, sham-controlled study was conducted in 39 hospitals. Patients with symptomatic ischaemic heart failure on guideline-directed therapy (n = 484) were screened; n = 348 underwent bone marrow harvest and mesenchymal stem cell expansion. Those achieving > 24 million mesenchymal stem cells (n = 315) were randomized to cardiopoietic cells delivered endomyocardially with a retention-enhanced catheter (n = 157) or sham procedure (n = 158). Procedures were performed as randomized in 271 patients (n = 120 cardiopoietic cells, n = 151 sham). The primary efficacy endpoint was a Finkelstein-Schoenfeld hierarchical composite (all-cause mortality, worsening heart failure, Minnesota Living with Heart Failure Questionnaire score, 6-min walk distance, left ventricular end-systolic volume, and ejection fraction) at 39 weeks. The primary outcome was neutral (Mann-Whitney estimator 0.54, 95% confidence interval [CI] 0.47-0.61 [value > 0.5 favours cell treatment], P = 0.27). Exploratory analyses suggested a benefit of cell treatment on the primary composite in patients with baseline left ventricular end-diastolic volume 200-370 mL (60% of patients) (Mann-Whitney estimator 0.61, 95% CI 0.52-0.70, P = 0.015). No difference was observed in serious adverse events. One (0.9%) cardiopoietic cell patient and 9 (5.4%) sham patients experienced aborted or sudden cardiac death.

CONCLUSION

The primary endpoint was neutral, with safety demonstrated across the cohort. Further evaluation of cardiopoietic cell therapy in patients with elevated end-diastolic volume is warranted.

Strategies for insulin initiation: insights from the French LIGHT observational study

BACKGROUND

The progressive nature of type 2 diabetes necessitates exogenous insulin use for most patients; basal insulin plus oral anti-diabetes drugs (OADs) is a well-validated way to facilitate insulin initiation. The primary aim of this study was to explore insulin initiation strategies and outcomes for patients using insulin detemir or glargine plus oral anti-diabetes drugs.

METHODS

LIGHT was a 3-month, longitudinal observational study conducted across 761 French centres in insulin-naïve type 2 diabetes patients managed under routine clinical care conditions, in either primary or secondary care. Endpoints included changes in HbA(1c) , fasting plasma glucose (FPG), rate of hypoglycaemia, weight, and adverse events.

RESULTS

Most physicians initiated a basal analogue to improve glycaemic control (97%), with many delaying beginning treatment for several months (9 ± 9.0 months for general practitioners, 10.2 ± 16.2 months for specialists). Most patients continued oral anti-diabetes drug therapy (95%) and lifestyle measures (92%), with 2-3 blood glucose readings per day and follow-up telephone calls for dose optimization. Mean change in HbA(1c) from baseline was - 1.3%, and - 3.1 mmol/L for fasting plasma glucose (both p < 0.0001). Hypoglycaemia increased from 1.4 to 5.6 events/patient/year (p < 0.0001), and weight decreased on average by 0.5 kg with detemir, with no change in glargine. Most patients (93%) reported being satisfied or very satisfied with their insulin.

CONCLUSIONS

Insulin initiation with detemir or glargine can be successfully managed in both primary and secondary care; the benefits of basal analogues (once-daily dosing, low rates of hypoglycaemia compared with neutral protamine Hagedorn) may have contributed to patient acceptance of the regimen.

[Erectile dysfunction in diabetic patients]

Because of its frequency, erectile dysfunction must be systematically screened for in diabetic patients because, according to a survey by the ADIRS-AFD, it has affected 66% of patients for a mean of 6 years, and 77% wish it could be treated. From a physiopathological point of view, erectile disorders in diabetic patients are related to the vascular and neurological complications of diabetes and the various associated risk factors. The treatment to propose is at first iPDE5, although there is a risk of lesser efficacy in a diabetic patient and potential contraindications with the administration of derived nitrates. Intracavernous injections of PGE1 are efficient and safe second line and specialised advice is only required in the case of failure.

[The opinion of patients treated with intracavernous injections: the EASY survey]

The primary objective of the EASY survey (Evaluation de l'Acceptation deS injections dans la dYsfonction érectile) was to study the feelings of patients treated for erectile disorders with long-term intracavernous injections of prostaglandin E1. The major criteria for abandoning treatment with IPDE 5 are, in descending order, inefficacy, cost and poor tolerance. Regarding the results with intracavernous injections of Edex, around 80% of patients were satisfied; 70 to 80% of those treated for risk factors and/or cardiovascular or neurological diseases and 55% of those treated following cancer of the prostate claimed that their sex life had improved.

[Purification of human plasma fibronectin by double affinity chromatography on gelatin and heparin-Trisacryl]

In this work the human plasma fibronectin was purified by affinity chromatography using a tandem column system. The first affinity column was filled with gelatin-Trisacryl whereas the second one contained heparin-Trisacryl. This double affinity chromatography demonstrated its high efficiency in term of purity and yield. Several analytical methods (electrophoresis, immunoelectrophoresis, F.P.L.C. and adhesion assay on cultured eucaryotic cells) evidenced in fact the high purity of the preparation as well as its biological behaviour in term of cell adhesion and spreading. The performances of the sorbents used facilitate the scaling up when large quantities of FNP are needed.

[Use of the brock punch for confection of a shunt between both ventricles, the ventricle and pulmonary artery or aorta without cardiopulmonary by-pass (CPB) (author's transl)]

Use of the Brock punch for placing a graft on the ventricle is a simple and easy technique not requiring CPB. This offers large experimental possibilities with clinical applications resulting from the experience gained in the laboratory.