Article from Oncology Site "Chemotherapy Advisor - Empowering Oncology Professionals"
December 04, 2012
Electroporation: Opening Doors to More Effective Chemotherapy and Ablation?
Recent reports show progress in the use of altered trans-membrane electrical fields to increase the efficiency of drug – and possibly, therapeutic gene – delivery into cells. Electroporation is also under investigation as a non-thermal tumor ablation modality.
The idea behind electroporation is simple: increase cells' trans-membrane voltage to transiently disrupt the molecular organization of membranes (creating new pores, as the name suggests), and you'll increase membranes' permeability to therapeutic agents – allowing anticancer drug molecules to diffuse more rapidly and efficiently into tumor cells, for example.
Pulsed electroporation to facilitate tumor cell uptake of bleomycin or cisplatin was first tried with patients in Europe in the 1990s. Two decades later, thousands of cancer patients have undergone these electrochemotherapies. While most studies have involved electrochemotherapy for melanomas, Kaposi sarcomas, and Merkel cell carcinomas, open-surgery, endoscopic and percutaneous modalities now allow electrochemotherapy for subcutaneous tumors, as well.
According to a September 2012 meta-analysis of data from 44 clinical studies, published online in the European Journal of Surgical Oncology, electroporation increases bleomycin's and cisplatin's antitumor efficacy “by more than 50%” (P 90% of patients with basal cell carcinoma and 70% of patients with squamous cell carcinoma at 6-month follow-up.
Electroporation shows preclinical promise as a component of multimodality anticancer regimens, as well. A recent mouse-model study of invasive ductal breast carcinomas of sizes “comparable to clinical lesions” found that combined radioelectrochemotherapy, involving a single low radiation dose of 3 Gy – 5 Gy plus cisplatin electrochemotherapy, was more effective than electrochemotherapy alone; in addition, electrochemotherapy was more effective at achieving remission at 100 days than was either electroporation or cisplatin chemotherapy alone.
Meanwhile, efforts to use electroporation to vector gene-therapy products to target cells – an effort initially undertaken in part as an attempt to circumvent the immune response and other challenges involved in virally-vectored gene delivery – appear to be paying off. OncoSec's ImmunoPulse DNA IL-12 system uses electroporation to enhance immunotherapy. A recently-reported phase 2 trial found the system, which involves intratumoral administration of DNA IL-12 during electroporation, is safe and well-tolerated, and might induce tumor regression and stabilization in metastatic melanoma.
Waitforit 52 --- The professional community is just beginning to notice as Oncosec is now being mentioned in connection with clinical results. Early last year, scientific finds would be discussed with no reference to the company.