Search

Use of cellular products for therapeutic purposes has predominantly been unregulated in Australia until recently. Transplant of haemopoietic progenitor cells (HPC) for bone marrow regeneration is now a routine treatment for many disorders with an established mechanism of facility accreditation. However, other cellular therapies do not have any form of accreditation, are not well evaluated and may be associated with significant risks. On 31 May 2011 the Therapeutic Goods Administration (TGA) implemented a long heralded regulatory biologicals framework for cell and tissue based therapies. The framework currently excludes human HPC, organs for direct transplantation and reproductive materials which are already covered by various forms of existing peer review and accreditation. This new framework is a practical approach for applying regulation based on the risk of the product to the recipient with four classes of product. Class 1 is reserved for the least regulated products and currently does not contain any proposed products. Class 2 will be for minimally manipulated products which will only require manufacturing compliance and evaluation against product and other mandatory standards before entry onto the Australian Register of Therapeutic Goods (ARTG). Class 3 and 4 products will be more than minimally manipulated and these cells and tissues may be used in a non-homologous manner. Class 3 and 4 products will represent a spectrum of risk where Class 4 therapies will represent the highest potential risk to the recipient, with the same requirements for Class 2 approvals but with additional requirements for comprehensive evaluation of a dossier for quality, safety and efficacy of the product. The extent of this quality, safety and efficacy data will depend upon the nature of the product and its associated risks, but will be more comprehensive for Class 4 as opposed to Class 3 products. The only truly contentious feature of this framework is the extremely high cost for dossier evaluation and the puzzling absence of an orphan drug scheme for biologicals.

Aim The objective of this study was to determine the in vivo distribution of dendritic cells (DC) when given to patients (pts) with Multiple Myeloma (MM) via varying routes of injection (intravenous- IV, intranodal- IN, intradermal-ID and subcutaneous-SC) by using ex vivo Indium111 Oxine (In111, T1/2 = 68h) labelled DC. Six (6) eligible pts had stable or slowly progressive MM not requiring systemic therapy with evidence of increased MUC-1 expression. Autologous monocytes were collected from each patient via apheresis and dendritic cells were produced by in vitro culture within the VacCell®processor. Method Cells were cultured for 7 days with GM-CSF and IL-13 on days 0 and 4 and after purification by counter-flow elutriation DC were pulsed with MUC1-Mannan fusion protein (24h) prior to use. DC were non-matured (imDC, n=3), or matured (mDC, n=3) with 1μg/ml FMKp and 500 UI/ml gamma IFN (6h) for subsequent In111 labelling. Cells were labelled with In111 (20 Mbq IV or 0.7 Mbq minimum each of IN, ID and SC) for 45–60 minutes in 0.9% NaCl with 5% autologous serum at room temperature, and washed twice before resuspension for administration. Pts received DC initially IV and then two weeks later by each of IN, SC, ID simultaneously. Pts at each DC administration were serially imaged using a planar gamma camera for up to 4 days. Results Mean DC labelling efficiency (based upon retained label in cells vs total label used) was 86% (54–95, n =12). Mean IV injection was 1.5 x 108 cells (0.33–2.5 x 108, n = 6), and IN, SC, ID was 2.0 x 107 cells (1.3–3.6 x 107, n = 6). IV: At 1 and 4h cells were predominantly visible in the lungs. After 24h -72h lungs were clearing with DC migrating to liver, spleen and later to bone marrow. ID and SC: imDC migrated to axillary LN in 1/3 ID and 1/3 SC injections whilst mDC tracked to LN in 2/3 ID injections and 3/3 SC injections. Quantitation of tracking was possible in 5/7 of the serial images. Table 1. Quantitative analysis of serial images after mDC and imDC injection indicating cells in the afferent axillary LN as a percentage of all cells injected ID or SC. Cell Preparation 4 hours 24 hours 48 hours 72 hours mDC SC 0.06% 0.22% 0.74% 1.30% mDC SC 0.10% 0.40% 0.67% 0.73% imDC ID 0.01% 0.14% 0.30% 0.48% mDC ID 0.02% 0.26% 0.43% 1.08% mDC ID 0.36% 0.80% 0.83% 1.29% IN: IN injections were retained within the node, but in 1/3 imDC and 2/3 mDC there was early and substantial drainage into an afferent LN (<4 hours, >3% of cells). Figure 1. Sequential planar gamma images (left to right, 2 hrs, 18 hrs, 51.5 hrs and 75 hrs after injection) in one pt after ID injection of mDC. The arrow indicates injection site over the right deltoid in the raised arm (shown as outline) with subsequent progressive accumulation of cells into afferent axillary LN. Conclusion ID and SC images suggest mDC track more consistently to LN, whilst IV mDC cleared more slowly from lungs at 24h compared to imDC. Figure 1. Sequential planar gamma images (left to right, 2 hrs, 18 hrs, 51.5 hrs and 75 hrs after injection) in one pt after ID injection of mDC. The arrow indicates injection site over the right deltoid in the raised arm (shown as outline) with subsequent progressive accumulation of cells into afferent axillary LN. Conclusion ID and SC images suggest mDC track more consistently to LN, whilst IV mDC cleared more slowly from lungs at 24h compared to imDC.

Radio-labelling of blood cells is an established technique for evaluating in vivo migration to sites of pathology such as infection and haemorrhage. We describe the use of two methods of cell labelling for tracking the destination of autologous-derived macrophage activated killer (MAK) cells linked to the bi-specific anti-her2neu antibody MDX-H210 delivered either by intravenous (iv) or intraperitoneal (ip) injection in ten patients with peritoneal relapse of epithelial ovarian carcinoma. Our results demonstrate the feasibility of generating high numbers and purity of GMP quality MAK cells, which can be efficiently radiolabeled. MAK cell administration produced minimal infusional toxicity and demonstrated a reproducible pattern of in vivodistribution to the lungs, liver and spleen in addition to active in vivotracking to sites of known tumor following either iv (8 of 16 infusions) or ip (4 of 6 infusions) using either 18F-FDG or 111In-labelled cells. The addition of MDX-H210 monoclonal antibody did not alter the distribution of cells to tumor sites, but did alter the in vivodistribution of cells administered by iv injection. This study demonstrates that cellular cancer immunotherapies may be successfully delivered to sites of active tumor and allows selection of those patients who may benefit from these approaches.

Aim