Does ex vivo CD34+ positive selection influence outcome after autologous hematopoietic stem cell transplantation in systemic sclerosis patients?

This EBMT Autoimmune Disease Working Party study aimed to evaluate the influence of CD34+ positive graft selection (CD34+) on the outcome of systemic sclerosis (SSc) patients after autologous hematopoietic stem cell transplantation (AHSCT). Clinical and laboratory data from 138 SSc patients at diagnosis, before and after AHSCT were retrospectively analyzed. CD34+ selection was performed in 47.1% (n=65) patients. By multivariate analysis adjusting for all factors differing between the two groups (without or with CD34+), there was no statistically significant difference in terms of overall survival (hazard ratio (HR): 0.98, 95% confidence interval (CI) 0.40-2.39, P=0.96), PFS (HR: 1.55, 95% CI 0.83-2.88, P=0.17) and incidence of relapse or progression (HR: 1.70, 95% CI 0.85-3.38, P=0.13). We demonstrate that CD34+ does not add benefit to the outcome of SSc patient treated with AHSCT. These findings should be further confirmed by prospective randomized trials.

Abstract POSTER-THER-1432: Intraperitoneal delivery of the disintegrin vicrostatin (VCN) effectively limits ovarian cancer growth and progression

Although prevention and early detection are the ultimate goals for ovarian cancer, the fact cannot be ignored that in 2014 21,980 women will be diagnosed with ovarian cancer in the U.S. 75% of these women will be confronted with a high stage tumor and a five-year survival rate of 45.5% (American Cancer Society, Atlanta). For these patients, improved treatment for residual disease following surgery, reduced complications during therapy as well as a decreased risk of cancer recurrence, would reduce mortality and improve their quality of life significantly. After surgery and first-line chemotherapy, 50% to 75% of responders will relapse within approximately 18 months and require further systemic therapy. Approximately 50% of women die due to carcinomatosis.

Exfoliated ovarian tumor cells are carried via peritoneal fluid to secondary sites in the abdominal cavity, where they attach, invade the submesothelial connective tissue and proliferate to create peritoneal micrometastasis. These cancer cells in effusions are not amenable to surgical removal, failure of their eradication is one of the main causes for unsuccessful treatment and recurrence.

The strategy of localized intraperitoneal (IP) chemotherapy targets these cells in particular and is therefore highly effective in preventing recurrence. According to the Cochrane database, IP chemotherapy successfully increased overall survival and progression free-survival, resulting in a 21.6% decrease in the risk of death. Therefore, the U.S. National Cancer Institute recommended consideration of IP chemotherapy for patients with advanced stage III ovarian cancer after optimal surgical debulking.

Integrins are heterodimeric receptors that evolved to mediate complex cell-ECM interactions. These interactions regulate the ability of cells to mechanically sense their environment by integrating multiple signaling pathways initiated by extracellular cues with the cell’s cytoskeleton. Integrins (including αvβ3, αvβ5, α5β1 and αvβ6) have important roles in OC cell attachment, survival, migration, invasion and angiogenesis. However, the precise roles played by different integrin subunits in various aspects of tumor progression and why some integrins appear to be especially supportive of tumor progression are still not fully understood. Due to their pivotal roles in OC biology, integrins represent an attractive target for a novel form of OC therapy.

Disintegrins are among the most potent soluble ligands of integrins representing a class of cysteine-rich polypeptides originally isolated from snake venom, many of which contain a cyclic-Arg-Gly-Asp (c-RGD) motif. These polypeptides hold a significant translational potential as anti-cancer therapeutic agents based on their high affinity interaction with integrins as well as their excellent pharmacological properties. However, these polypeptides are extremely difficult to produce recombinantly. Previously the Markland group reported that a sequence-engineered RGD-disintegrin (called vicrostatin or VCN) can be reliably produced in large quantity. Through multiple integrin ligation (i.e., αvβ3, αvβ5 and α5β1), VCN targets both endothelial and OC cells. The use of small RGD peptides or multimeric cyclic RGD peptides for targeting of integrins for both therapy and imaging of tumors has been widely reported but there is a distinct advantage to the use of disintegrins such as VCN. VCN not only acts as an antagonist (in a manner identical to RGD peptides), VCN also elicits signaling responses through direct interaction with integrins.

Importantly, integrin αvβ3 is expressed at very low level on epithelial cells and mature endothelial cells, but is overexpressed on the endothelial cells of the tumor neovasculature and on tumor cells. Therefore, this integrin presents an attractive and tumor specific therapeutic target for rapidly growing solid tumors. In the present studies we delivered VCN formulated in a novel carboxymethyl cellulose (CMC) polyethyleneoxide (PEO) gel (Oxiplex™) through IP delivery.

In studies described here we show that IP VCN delivery via Oxiplex™, following implantation of SKOV-3 sphereoids and confirmation of tumor growth by bioluminescent imaging, significantly reduced tumor growth and dissemination. In addition we have evaluated the dose of VCN delivered and the timing of the administrations and shown that a clinically relevant dosing schedule can be achieved.

Citation Format: S. Swenson, R. Minea, J. Moore, M. Mikhail, Z. Kirakosyan & Francis S. Markland Jr. Intraperitoneal delivery of the disintegrin vicrostatin (VCN) effectively limits ovarian cancer growth and progression [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-THER-1432.

REpeated AutoLogous Infusions of STem cells In Cirrhosis (REALISTIC): a multicentre, phase II, open-label, randomised controlled trial of repeated autologous infusions of granulocyte colony-stimulating factor (GCSF) mobilised CD133+ bone marrow stem cells in patients with cirrhosis. A study protocol for a randomised controlled trial

INTRODUCTION

Liver disease mortality and morbidity are rapidly rising and liver transplantation is limited by organ availability. Small scale human studies have shown that stem cell therapy is safe and feasible and has suggested clinical benefit. No published studies have yet examined the effect of stem cell therapy in a randomised controlled trial and evaluated the effect of repeated therapy.

METHODS AND ANALYSIS

Patients with liver cirrhosis will be randomised to one of three trial groups: group 1: Control group, Standard conservative management; group 2 treatment: granulocyte colony-stimulating factor (G-CSF; lenograstim) 15 µg/kg body weight daily on days 1-5; group 3 treatment: G-CSF 15 µg/kg body weight daily on days 1-5 followed by leukapheresis, isolation and aliquoting of CD133+ cells. Patients will receive an infusion of freshly isolated CD133+ cells immediately and frozen doses at days 30 and 60 via peripheral vein (0.2×10(6) cells/kg for each of the three doses). Primary objective is to demonstrate an improvement in the severity of liver disease over 3 months using either G-CSF alone or G-CSF followed by repeated infusions of haematopoietic stem cells compared with standard conservative management. The trial is powered to answer two hypotheses of each treatment compared to control but not powered to detect smaller expected differences between the two treatment groups. As such, the overall α=0.05 for the trial is split equally between the two hypotheses. Conventionally, to detect a relevant standardised effect size of 0.8 point reduction in Model for End-stage Liver Disease score using two-sided α=0.05(overall α=0.1 split equally between the two hypotheses) and 80% power requires 27 participants to be randomised per group (81 participants in total).

ETHICS AND DISSEMINATION

The trial is registered at Current Controlled Trials on 18 November 2009 (ISRCTN number 91288089, EuDRACT number 2009-010335-41). The findings of this trial will be disseminated to patients and through peer-reviewed publications and international presentations.

Pragmatism, mathematical models, and the scientific ideal of prediction and control

Mathematical models are often held to be valuable, if not necessary, for theories and explanations in the quantitative analysis of behavior. The present review suggests that mathematical models primarily derived from the observation of functional relations do indeed contribute to the scientific value of theories and explanations, even though the final form of the models appears to be highly abstract. However, mathematical models not primarily so derived risk being essentialist in character, based on a particular view of formal causation. Such models invite less effective and frequently mentalistic theories and explanations of behavior. Models may be evaluated in terms of both (a) the verbal processes responsible for their origin and development and (b) the prediction and control engendered by the theories and explanations that incorporate the models, however indirect or abstract that prediction and control may be. Overall, the present review suggests that technological application and theoretical contemplation may be usefully viewed as continuous and overlapping forms of scientific activity, rather than dichotomous and mutually exclusive.

The weight debate

Therapeutic interventions administered on Critical Care are often dosed on the basis of patient body size, to ensure treatments are effective in achieving their goals and to prevent harm from overdose. Many treatment modalities use predicted weights estimated from descriptors such as sex, weight and height to reduce error that is associated with using total body weight in critically ill patients. In this article we review the size descriptors that have been described, their origin and calculation. We then examine the role they play in dosing of common therapies utilised in Critical Care and potential areas of research for the future.