Lymphoma Chemovirotherapy: CD20-Targeted and Convertase-Armed Measles Virus Can Synergize with Fludarabine

Abstract

Combination chemotherapy regimen incorporating CD20 antibodies are commonly used in the treatment of CD20-positive non-Hodgkin's lymphoma (NHL). Fludarabine phosphate (F-araAMP), cyclophosphamide, and CD20 antibodies (Rituximab) constitute the FCR regimen for treating selected NHL, including aggressive mantle cell lymphoma (MCL). As an alternative to the CD20 antibody, we generated a CD20-targeted measles virus (MV)-based vector. This vector was also armed with the prodrug convertase purine nucleoside phosphorylase (PNP) that locally converts the active metabolite of F-araAMP to a highly diffusible substance capable of efficiently killing bystander cells. We showed in infected cells that early prodrug administration controls vector spread, whereas late administration enhances cell killing. Control of spread by early prodrug administration was also shown in an animal model: F-araAMP protected genetically modified mice susceptible to MV infection from a potentially lethal intracerebral challenge. Enhanced oncolytic potency after extensive infection was shown in a Burkitt's lymphoma xenograft model (Raji cells): After systemic vector inoculation, prodrug administration enhanced the therapeutic effect synergistically. In a MCL xenograft model (Granta 519 cells), intratumoral (i.t.) vector administration alone had high oncolytic efficacy: All mice experienced complete but temporary tumor regression, and survival was two to four times longer than that of untreated mice. Cells from MCL patients were shown to be sensitive to infection. Thus, synergy of F-araAMP with a PNParmed and CD20-targeted MV was shown in one lymphoma therapy model after systemic vector inoculation. [Cancer Res 2007;67(22):10939-47]

Chemovirotherapy for head and neck squamous cell carcinoma with EGFR-targeted and CD/UPRT-armed oncolytic measles virus

“…The coding sequence of the single-chain variable fragment against EGFR 27 was synthesized (Eurofins MWG, Ebersberg, Germany) containing flanking 5 0 -NotI and 3 0 -SfiI cloning sites. The NotI-SfiI fragment was inserted via exchange subcloning in pCG-HmutI-aCD20 containing the 'blind' H protein with CD46-and SLAM-ablating mutations 10 leading to pCG-HmutI-aEGFR. Thereof, the EGFR-retargeted PacI-SpeI fragment was isolated and exchanged in pMV-EGFP resulting in the full-length genomic plasmid pMV-EGFP-antiEGFR.…”

“…7 Measles virus (MV) vectors based on the vaccinelineage MV-Edmonston have proven to be a platform with broad utility, having been developed for the treatment of several types of cancer in preclinical settings. [8][9][10][11][12][13][14][15][16] Since 2005, clinical trials including Phase I studies for treatment of ovarian cancer, myeloma and recurrent glioma are going on. [17][18][19] Currently, improved specificity and efficacy are the main aims in the process of rational MV vector design.…”

“…Expression of this particular transgene allows the virus to synergize with current clinical therapies, with purine nucleoside phosphorylase activating the clinically approved lymphoma drug fludarabine within the tumor microenvironment leading to bystander killing of uninfected tumor cells. 10 A similar mechanism of action is the basis for treatment with the bi-functional prodrug convertase cytosine deaminase/uracil phosphoribosyltransferase (CD/UPRT) that locally activates the non-toxic prodrug 5-fluorocytosine (5-FC) to the chemotherapeutics 5-FU and 5-FU monophosphate. When converted into its active metabolites, 5-FU inhibits thymidylate synthase by incorporation into DNA and RNA eventually leading to inhibition of DNA and RNA synthesis and interference with DNA repair.…”

Stratégies génétiques, immunologiques et pharmacologiques au service d’une nouvelle génération de virus anticancéreux

“…Par exemple, l'expression de TRAIL (tumor necrosis factor related apoptosis inducing ligand) et de l'interleukine 24 par des virus oncolytiques a permis d'améliorer l'efficacité de ces virus contre les cellules cancéreuses [17]. D'autres recherches ont conduit au développement de virus armés d'enzymes qui convertissent localement une prodrogue inactive en une substance toxique pour les cellules environnantes [18]. Dans une approche similaire, le gène du symporteur de sodium/iodure (NIS) a été incorporé à plusieurs types de virus oncolytiques.…”

Le virus de la rougeole

“…Même si le faible effectif de patients et/ou le . Ainsi, des modifications de la protéine H ont permis sa liaison au récepteur PSCA (prostate stem cell antigen) exprimé sur les cellules cancéreuses prostatiques et pancréa-tiques [14], au prostate-specific membrane antigen (PSMA) surexprimé sur les cellules prostatiques [19], à l'ACE exprimé sur les cellules cancéreuses coliques [15], au CD20 exprimé par les cellules lymphomateuses [16], à une forme mutante (EGFRvIII) du récepteur à l'EGF (epidermal growth factor) ou au récepteur de l'interleukine-13, tous deux surexprimés par les cellules de gliome [17,18]. Ces changements de la spécifi-cité de reconnaissance par le virus des cellules cibles doit permettre d'augmenter la sécurité du traitement.…”