Guillaume Serin

Discovery of a 9-mer Cationic Peptide (LTX-315) as a Potential First in Class Oncolytic Peptide

Oncolytic immunotherapies represent a new promising strategy in the treatment of cancer. In our efforts to develop oncolytic peptides, we identified a series of chemically modified 9-mer cationic peptides that were highly effective against both drug-resistant and drug-sensitive cancer cells and with lower toxicity toward normal cells. Among these peptides, LTX-315 displayed superior anticancer activity and was selected as a lead candidate. This peptide showed relative high plasma protein binding abilities and a human plasma half-life of 160 min, resulting in formation of nontoxic metabolites. In addition, the lead candidate demonstrated relatively low ability to inhibit CYP450 enzymes. Collectively these data indicated that this peptide has potential to be developed as a new anticancer agent for intratumoral administration and is currently being evaluated in a phase I/IIa study.

Synthesis, σ1, σ2-receptors binding affinity and antiproliferative action of new C1-substituted adamantanes

The synthesis of N-{4-[a-(1-adamantyl)benzyl]phenyl}piperazines 2a-e is described. The in vitro antiproliferative activity of most compounds against main cancer cell lines is significant. The σ(1), σ(2)-receptors and sodium channels binding affinity of compounds 2 were investigated. One of the most active analogs, 2a, had an interesting in vivo anticancer profile against the BxPC-3 and Mia-Paca-2 pancreas cancer cell lines with caspase-3 activation, which was associated with an anagelsic activity against the neuropathic pain.

New Adamantane Phenylalkylamines with σ-Receptor Binding Affinity and Anticancer Activity, Associated with Putative Antagonism of Neuropathic Pain

The synthesis of the adamantane phenylalkylamines 2a-d, 3a-c, and 4a-e is described. These compounds exhibited significant antiproliferative activity, in vitro, against eight cancer cell lines tested. The σ(1), σ(2), and sodium channel binding affinities of compounds 2a, 3a, 4a, and 4c-e were investigated. The most interesting analogue, 4a, exhibited significant in vivo anticancer profile on pancreas, prostate, leukemia, and ovarian cancer cell line xenografts together with apoptosis and caspase-3 activation. Inhibition of the cancer cells cycle at the sub-G1 level was also obtained with 4a. Finally, encouraging results were observed with 4a in vivo on mice, suggesting putative antimetastatic and analgesic activities of this compound.

Abstract 3471: Comparative assessment of in vitro activity and aactivated progesterone receptor (APR) biomarker predictivity for multiple antiprogestins

Proceedings: AACR 106th Annual Meeting 2015; April 18-22, 2015; Philadelphia, PA Background: In absence of ligand, PRA and PRB are evenly distributed in nuclei in cell lines. Upon ligand binding, PRA and PRB dimerizes and form discrete focal subnuclear distribution patterns, which are associated with transcriptional activation of PR. This pattern corresponds to the transcriptionally active form of PR and serves as an APR biomarker. The expression of APR in cell lines was demonstrated to be predictive of onapristone antiproliferative effects (Serin, Abs # 473, NCI-AACR-EORTC 2012). In this study the correlation of APR to the antiproliferative effects of different antiprogestins (Type I & type II, and steroidal/non-steroidal chemical structures) is examined. Method: T47D and CAMA-1, two PR expressing breast cancer cell lines, were grown in either FBS or Steroid Free FBS (SFFBS). In FBS, single agent anti-progestins were studied; in SFFBS, cell lines were stimulated with estradiol (E2) or progesterone (P4) and antiprogestins tested. All experiments were performed in duplicate. APR was analyzed at 6h and 30h using paraffin embedded cellular pellets, and processed with standard IHC techniques. Cellular viability was measured by the MTS assay at 30h, 4d and 7d. Antiprogestin drugs tested included: Aglepristone, Mifepristone, Onapristone, PF02413873, ZK230211, and ZM150271. Results: In the T47D cell line, in FBS between zero and ∼ 40% antiproliferative activity was observed from D1 to D7 for all antiprogestins. In SFFBS, T47D proliferation at D7 was increased >300% by E2 and >200% by P4. All antiprogestins opposed P4 and E2 proliferative effects at D7, with a max of 80% inhibition relative to control. In the CAMA-1 cell line, in FBS weak antiprogestin antiproliferative effect was observed (<20% inhibition); with SFFBS, P4 and E2 were weakly stimulatory and antiprogestins had an inconsistent and weak treatment effect. The effect of antiprogestins were not dose dependent. APR: in T47D and FBS, APR was observed at 6h consistently for PR A and PR B. At 30h, controls were APR positive, and with Aglepristone, Mifepristone and Onapristone treatment, the surviving cells were APR neg; PF02413873, ZK230211and ZM150271 APR effect was inconsistent. Specimens from SFFBS are under evaluation. For CAMA-1, in FBS PRA and PRB were weakly expressed i.e. in 5% of the cells; APR was always negative. Specimens from SFFBS are under evaluation. Conclusion: The cell line expressing APR, T47D, is sensitive to direct antiprogestins effect in FBS, to E2 and P4 growth stimulation in SFFBS. In T47D, there was an antagonism by all antiprogestins at D7 and APR status was reversed at 30 h completely in 3/6 cases and incompletely in 3/6. CAMA-1 does not express APR, is weakly stimulated by E2 and P4, and antiprogestins have inconsistent effects in this cell line. APR status is a predictor of antiprogestin action. Citation Format: Alexander Zukiwski, Erard Gilles, Guillaume Serin, Jacques Bosq, Charline Alleaume. Comparative assessment of in vitro activity and aactivated progesterone receptor (APR) biomarker predictivity for multiple antiprogestins. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3471. doi:10.1158/1538-7445.AM2015-3471

Abstract 5459: Antitumor activity of EP80061, a small-glyco drug in preclinical studies

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Background: Heparan sulphate (HS) containing proteoglycans regulate the activity of many proteins (growth factors, cytokines, adhesion molecules…) involved in pathologies like cancer, inflammation, cardiovascular, metabolic and neurodegenerative diseases, as well as in viral infection. HS mimicking oligosaccharides can interfere with protein/HS interactions and thus modulate the resulting biological effects. The optimization of fully synthetic HS mimetics exhibiting anti-tumour and anti-metastatic properties is currently in progress. Methods: Compound selection was performed using classical in vitro assays (binding and proliferation) and a cellular angiogenesis assay (Angiokit®). In vivo, Swiss nude mice subcutaneously (SC) xenografted with A-673 human rhabdomyosarcoma tumor cells were used to compare compounds showing significant anti-tumour activity. Compounds were intraperitonealy (IP) injected on a daily basis. The most potent compound was then evaluated on syngeneic mouse models: C57 BL/6 mice intravenously (IV) injected with B16-F10 malignant melanoma cells and Balb/c mice bearing orthotopic (OT) Renca kidney carcinoma. Results: Binding assays to FGF-2, PDGF-BB, VEGF-B and SDF-1α in Biacore experiments and growth factor-dependent proliferation tests led to the identification of several inhibitors. Optimized compounds exhibiting anti-angiogenic activities were selected in Angiokit® assays. EP80061 was selected for further studies on the basis of significant activity in this assay. In A-673 SC mouse model, EP80061 was also the most powerful compound. When IP injected at 30 mg/kg/inj. for 28 consecutive days, it induced a marked tumour growth delay. At D22, the optimal T/C value (46%) was reached with a significantly lower tumour volume (p=0.0006, 1672 ± 760 and 765 ± 402 mm3 for vehicle and EP80061 treated mice, respectively). EP80061 induced also a very significant decrease in lung metastasis development in B16-F10 IV injected mice treated at 30 mg/kg/inj. (p<0.0001, 92 ± 24 and 12 ± 8 metastases for vehicle and EP80061 treated mice, respectively). Promising results were also obtained on OT Renca bearing mice where EP80061 induced a decrease of OT tumour size. Conclusion: Current preclinical results support EP80061 as a lead candidate for further developments of small-glyco drugs as anticancer compounds. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5459.

Abstract 3741: Antimetastatic activity of ISTH0047, a potent and selective TGF-beta 2 antisense oligonucleotide, in syngeneic lung metastatic model of mouse 4T1 mammary carcinoma

Transforming growth factor beta (TGF-β) isoforms are the primary mediators for TGF-β signaling via TGF-β receptors and downstream phosphorylation/dephosphorylation cascade. TGF-β is associated with a wide range of biological processes in oncology, including tumor cell invasion, migration, angiogenesis, immunosuppression, as well as regulation of tumor stem cell properties. Mouse 4T1 mammary carcinoma cell line is a transplantable tumor cell line that is highly tumorigenic and invasive and, unlike most tumor models, can spontaneously metastasize from the primary tumor in the mammary gland to multiple distant sites including lymph nodes, blood, liver, lung, brain, and bone. Considering rather challenging preclinical evaluation of antitumor activity in tumor models, mouse 4T1 mammary carcinoma model has been widely used in the literature for evaluation of TGF-β antagonists. In this report, we describe the efficacy of ISTH0047 - a potent and selective TGF-β2 antisense oligonucleotide - in murine 4T1 primary tumors and lung metastasis following tumor cell injection into the mammary fat pad (orthotopic tumor model) of syngeneic Balb/c mice. Consistent with literature data generated with other classes of TGF-β antagonists (e.g., small-molecule kinase inhibitors, antibodies or TGF-β trap agents), although limited antitumor activity was demonstrated on primary tumor growth, marked and statistically significant decrease of lung metastasis number was observed upon subcutaneous administrations of ISTH0047. In addition, side by side comparison with murine surrogates of CTLA-4 or PD-1 antibodies indicated similar efficacy of all test items on lung metastasis in this model. Taken together, these encouraging results pave the way for in-depth preclinical evaluation of both ‘seed and soil’ theory and efficacy of combination regimen (immunomodulation) for better clinical outcome. Citation Format: Katja Wosikowski, Kathy Hasenbach, Jutta Petschenka, Diana Barea Roldan, Sebastian Kreiter, Ugur Sahin, Guillaume Serin, Julie-Orlane Redon, Marc Hillairet de Boisferon, Francis Bichat, Hanna Kohonen, Michel Janicot. Antimetastatic activity of ISTH0047, a potent and selective TGF-beta 2 antisense oligonucleotide, in syngeneic lung metastatic model of mouse 4T1 mammary carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3741.

Abstract 328: Antitumor activity of the oncolytic peptide LTX-315 in syngeneic tumor models

Cationic antimicrobial peptides (CAPs) are naturally occurring molecules found in a number of species as a defense mechanism for eukaryotic cells against pathogens and are an integral part of the innate immune system. CAPs have a broad spectrum of activities including antimicrobial and anticancer while being less cytotoxic toward non-malignant cells. The potential therapeutic application against cancer has spawned an interest in developing oncolytic agents that display a new mode of action to overcome the potential drug resistance associated with other current therapeutics. The anticancer effects of CAPs are still under investigation, but several peptides have already exhibited a promising potential with cytotoxic activities against a broad spectrum of tumor cells. Oncolytic peptides exert their activity through either a membranolytic mode of action or an interaction with intracellular targets, or a combination of both. LTX-315 (K-K-W-W-K-K-W-Dip-K-NH2), a novel oncolytic peptide developed by Lytix Biopharma AS has the potential to adopt an amphipathic helical coil structure. In vitro studies have demonstrated that it was highly effective against both drug-resistant and drug-sensitive cancer cells from several organ origins, with lower toxicity toward normal cells. LTX-315 was designed for intratumoral treatment of transdermal lesions. Previously, LTX-315 has been shown to induce complete regression of B16 melanomas and long lasting antitumor immune responses. Histological analyses of treated tumors revealed extensive hemorrhagic necrosis and infiltration of CD3+ T cells. Moreover, mRNA levels of inflammatory cytokines such as IL1β, IL6 and IL18 were found to be increased in the tumor tissue after LTX-315 treatment. The treatment did also prevent lung metastasis in mice re-challenged with B16F1 cells intravenously. Due to its oncolytic mode of action, LTX-315 induces immunogenic cell death through the release of danger-associated molecular pattern molecules and tumor antigens. Recently, we have demonstrated that when subcutaneously established EMT-6 tumors (inoculated into both flanks of the animal) were treated intratumorally with LTX-315, an antitumor response was observed with a T/C ratio of 17% 19 days post start of treatment. Furthermore, an abscopal effect of LTX-315 on the untreated tumor was also reported but only when it was combined with anti-PD-L1 antibody. At the end of study, 50% of mice that had received the combination therapy were still alive vs 30% and 40% in the groups treated with LTX-315 or anti-PD-L1 antibody alone, respectively. In conclusion, LTX-315 seems to be an ideal combinations partner for immune checkpoint inhibitors. Citation Format: Ketil Andre Camilio, Baldur Sveinbjornsson, Sylvie Maubant, Guillaume Serin, Jean-Francois Mirjolet, Francis Bichat, Oystein Rekdal. Antitumor activity of the oncolytic peptide LTX-315 in syngeneic tumor models. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 328.

Abstract 3126: Renca RCC syngeneic model to evaluate efficacy of novel antisense oligonucleotides targeting TGF-β isoforms

Transforming growth factor beta (TGF-β represents a family of cytokines, which function as the primary mediators for TGF-β signaling via TGF-β receptor type II (TβIIR) and both non-canonical and canonical downstream signaling pathways. TGF-β is associated with a wide range of biological processes in oncology, including tumor cell invasion, migration, angiogenesis, immunosuppression, as well as regulation of tumor stem cell properties. Hence, optimal preclinical evaluation of efficacy of TGF-β antagonists is challenging. Isarna Therapeutics has designed and developed selective and potent LNA-modified antisense oligonucleotides targeting the various TGF-β isoforms. In order to adequately evaluate selected preclinical development candidates, Oncodesign has developed customized experimental Renca tumor models in syngeneic and/or immunodeficient mice. The Renca cell line was established from a murine transplantable renal adenocarcinoma of spontaneous origin, and has been used under various experimental conditions: (1) subcutaneous tumor model by inoculating cells into the flanks of the animals; (2) the pulmonary metastatic tumor model by an intravenous injection of cells into the tail vein; and (3) the orthotopic tumor model by injecting cells into the renal subcapsule (and subsequent pulmonary metastasis). Outcome of this development program and preliminary results for selected TGF-β antisense oligonucleotides will be presented and discussed. Citation Format: Hanna Korhonen, Julie-Orlane Redon, Damien France, Guillaume Serin, Francis Bichat, Frank Jaschinski, Katja Wosikowski, Michel Janicot. Renca RCC syngeneic model to evaluate efficacy of novel antisense oligonucleotides targeting TGF-β isoforms. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3126. doi:10.1158/1538-7445.AM2014-3126

Abstract 1317: Antiprogestin drug development: in vitro validation of a potential clinical biomarker.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Background: Antihormonal agents (AH) are some of the most clinically useful anticancer drugs. AH resistance and the availability of alternative treatments have made patient selection increasingly important for AH drug development. We hypothesized that the progesterone receptor (PR) may be constitutively active because of the aberrant biological pathways and that selecting patients with baseline tumor PR activation would predict for antiprogestin activity. Activated PR (APR) can be visualized in nuclei as fluorescent aggregates via fluorescent green protein engineered PR cell lines in vitro and by immunofluorescence (IF) in tissues. The detection of PR foci has been associated with transcription and gene activation in vitro. PR phosphorylation (phos) is induced by a variety of pathways. We have developed a IHC method that allows APR determination in tumor biopsies on a routine basis (SABCS 2012). The predictive nature of the observation of APR by IHC in vitro has been tested with onapristone (ONA) for cell survival and proliferation. Methods: 8 human breast cancer (BT-474, CAMA-1, EVSA-T, HCC-1954, MCF-7, MDA-MB-231, T-47D, ZR-75-1) and 2 human endometrial cancer (Ishikawa, HEC-1-A) cell lines were studied. Cytoblocks for APR analysis were made for each time point and experimental condition, baseline ER/PR expression was determined by IHC and PR phos was analyzed with specific antibodies (pSER162, 190, 294, 400, 554) by Western Blotting and IHC. Culture conditions: normal and stripped FBS, +/- ONA and growth factor/hormone exposure (EGF, FGF2, E2 and P4) in triplicate. Analysis was performed at baseline (BL), 6h, 96h and 7 days. Cell viability was assessed by MTS assay, proliferation was studied by Ki67 analysis. APR foci were determined by IHC and read by a pathologist blinded to the experimental conditions. Results: At BL only two cell lines were PR pos/APR pos (T47D, CAMA-1) and all other cell lines where PR pos/APR neg (BT-474, EVSA-T, HCC-1954, MCF-7) or PR neg/APR neg (Ishikawa, HEC-1-A, MDA-MB-231, ZR-75-1). ONA exerted inhibitory effect only in APR pos cell lines. In stripped FBS at 6h, T47D APR pos status was converted to APR neg by ONA except with E2 stimulation which required longer treatment. The CAMA-1 data are not yet available. No APR neg cell lines were converted into APR pos except in one experiment after protracted exposure to EGF. ONA generally decreased phos; phos decrease measured by WB did not correlate with growth inhibition. Phos status determined by IHC and Ki67 proliferation assessment are currently in process and will be presented with the confirmatory data. Conclusions: Baseline APR positivity is predictive of ONA activity in vitro. ONA converts APR pos cells to APR neg within 6h in most cases, a time frame consistent with PR biology. The growth inhibitory effects of ONA were not correlated to PR phos in the cell lines and conditions tested. The APR IHC methodology may be applicable in the clinical setting. Citation Format: Erard Gilles, Laura Caplier, Alexander Valent, Guillaume Serin, Anne Gompel, Jacques Bosq, Alexander Zukiwski. Antiprogestin drug development: in vitro validation of a potential clinical biomarker. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1317. doi:10.1158/1538-7445.AM2013-1317

Abstract 5383: Evaluation of immune response in preclinical settings

Among all new strategies against cancer, the treatments with vaccines, biologics, antibodies, antibody fragments, and other immunological modulators are promising. All of them aim to be more targeted, more effective, and less toxic than other therapies. In order to be developed and accurately evaluated, these immunological related therapies need appropriated preclinical models and relevant immunological readouts. Most of these immunological readouts should be analyzed in vitro, in vivo and ex vivo. A panel of tools from rodents to the bench was evaluated toward the modulation of the immune system by new therapies. All these protocols were developed and validated properly to evaluate these new immunology related cancer therapies. In immunocompetent mice, the immune cells were studied for their cell surface activation markers detection, induction of proliferative phenotype, antigen-specific T lymphocyte detection, secretion of soluble mediators such as cytokines … using FACS phenotyping, cytometric bead assay (CBA) or Luminex multiplex technologies and ELISPOT. In immunodeficient mice, the reconstitution of the mature human immune system with PBMC or naive human immune system using hematopoietic stem cells were used to evaluate the modulation of those immune cells by therapies through human cytokine release, onset of graft versus host disease. Among other examples, characterization of antibody function (Fab and Fc mediated activities), quantification of the existence and function of antigen-specific T cell clones, phenotyping study of immune cells for activation markers as well as multiplex assays to understand the cytokines network, differentiation of hematopoietic cells by colony formation unit will be described. All of them will be presented in the context either of rodent syngenic model or humanized mouse model. All results, integrative data and examples will be presented in the poster. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5383. doi:1538-7445.AM2012-5383