Exhibit 99.1

P - 161: A PHASE I DOSE - ESCALATION STUDY TO ASSESS THE ONCOLYTIC VIRUS VCN - 01 SAFETY AND EFFICACY IN REFRACTORY RETINOBLASTOMA PATIENTS Jaume Catalá - Mora1,*, Jaume Mora 1,2 , Margarida Simao 1 , Francis Munier 3 , Livia Romero 4 , Ligia Fu 5 , Jesus Ardila 6 , Ida Russo 7 , Karina Senyase Zamarripa 8 , Jesús Díaz - Cascajosa 1 , Eduard Pedemonte - Sarrias 1 , Marina Barraso - Rodrigo 1 , Itziar Alonso Colmenero 1 , Dolors Molies - Navarrete 1 , Ana Mato - Berciano 9 , Carmen Blasco 9 , Manel Cascallo 9 , Guillermo L. Chantada 10 , Ángel Montero - Carcaboso 10 1 Hospital Sant Joan de Déu, Barcelona, Esplugues de Llobregat, Barcelona, Spain; 2 Pediatric Cancer Center Barcelona, Hospital Sant Joan de Déu, Barcelona, Spain; 3 Hopital Ophtalmique Jules Gonin, Lausanne, Switzerland; 4 Unidad Oncología Ocular Instituto Oncológico Dr. Luis Razetti, Caracas, Venezuela; 5 Hospital Escuela Universitario, Tegucigalpa, Honduras; 6 Centro Médico Imbanaco, Cali, Colombia; 7 Ospedale Pediatrico Bambino Gesù, Roma, Italy; 8 HONU Childcare, Leon, Guanjuato, Mexico; 9 Theriva Biologics, Parets del Vallès, Barcelona, Spain; 10 Fundació Sant Joan de Déu, Espplugues de Llobregat, Barcelona, Spain. Patients (from 1 year to under 12 years of age) with intraocular retinoblastoma who failed conservative therapy facing imminent enucleation were eligible for this phase I, dose - escalation study (NCT 03284268 ) with two dose levels of VCN - 01 intravitreal injection ( 2 E+ 9 vp/eye per dose for the first patient) and 2 E+ 10 vp/eye dose in two doses on day 1 and 15 for the remaining 8 patients . The primary objective was to determine the safety and tolerability of intravitreal injections of VCN - 01 through assessment of adverse events and laboratory tests to establish the maximum tolerated dose (MTD) of VCN - 01 virus . Dose limiting toxicity (DLT) was defined as ≥ grade IV ocular toxicity or ≥ grade III systemic toxicity according to CTCAEv 04 . Response assessed by RB - RECIST criteria and toxicity were evaluated at day 42 of the first injection . Additionally, different biological samples were obtained to evaluate the excretion profile of VCN - 01 and to assess immune response by the presence of neutralizing antibodies in patients . Trial Design & Methods Retinoblastoma is the most frequent intraocular malignancy in children . Novel treatments must address three main needs : tumor selectivity to maximize anticancer action, reduced toxicity in healthy eye tissues, and reduced exposure to chemotherapy to minimize the risk of subsequent malignant neoplasms . Zabilugene almadenorepvec (VCN - 01 ) 1 is an oncolytic adenovirus targeting the E 2 F pathway and expressing hyaluronidase that is currently being tested in several indications : Preclinical work demonstrated antitumor activity for retinoblastoma in patient derived retinoblastoma models 2 . Additionally, evidences for VCN - 01 tumor selectivity were collected, with absence of replication in normal retinas in rabbit . We report here a first - in - children study aiming to assess its safety profile and initial efficacy . Background Results/Graphs/Data *Address correspondence to : Jaume Català Mora (jaume . catala@sjd . es) References 1. Rodríguez - García A et al. (2015) Safety and efficacy of VCN - 01, an oncolytic adenovirus combining fiber HSG - binding domain replacement with RGD and hyaluronidase expression. Clin Cancer Res 21:1406 - 18 2. Pascual Pasto G et al. (2019) Therapeutic targeting of the RB1 pathway in retinoblastoma with the oncolytic adenovirus VCN - 01. Sci Transl Med 11:eaat9321 D1 D15 D28 D45 D180 MRI - MDD Oft - ERG Safety visit 6 months Follow - up VCN - 01 Oft - Lab ERG VCN - 01 MRI - MDD Oft - ERG Demographics High dose Low dose 2E+10 vp/eye (n=8) 2E +9 vp/eye (n=1) 3.2 2 Median Age, years (2 - 7) NA Range 5/3 0/1 Sex (Male / Female) 16.35 12 Median Weight, Kg (9,4 - 31.0) NA Range 103.5 98 Median Height, cm (87 - 126) NA Range 3 1 Somatic Type of mutation RB1 gene 5 NA Germinal 5 NA With active tumor in ONLY one eye, and the contralateral eye already enucleated If germinal 0 0 A Group IIRC Classification for Intraocular retinoblastoma (International Intraocular Retinoblastoma Classification) 1 0 B Group 2 0 C Group 5 1 D Group 0 0 E Group Previous treatments Vitreous seeds Subretinal Seeds Retinal tumor IIRC Laterality Patient (dose) Intravitreal chemotherapy Intraarterial chemotherapy - Mel / Topo + + + D Unilateral #1 (2.0x10 9 vp) - - + - + D Bilateral #2 (2.0x10 10 vp) Mel Carbo /Mel / Topo + - + C Bilateral #4 (2.0x10 10 vp) Mel / Topo - + - + D Unilateral #5 (2.0x10 10 vp) Carbo /Mel - + - + D Bilateral #8 (2.0x10 10 vp) Topo - + + + D Bilateral #9 (2.0x10 10 vp) Topo Carbo /Mel / Topo + - - C Unilateral #11 (2.0x10 10 vp) Topo Carbo /Mel / Topo + - + B Bilateral #12 (2.0x10 10 vp) Topo Carbo /Mel / Topo + - + D Unilateral #13 (2.0x10 10 vp) Conclusions Acknowledgements VCN - 01 was well tolerated, uveitis being the most common adverse effect. VCN - 01 did not cause retinal toxicity. The response in these heavily pre - treated eyes was encouraging. Safety Profile Grade 3 All Grades Description/Nature of the event (MedDRA PT) MedDRA System Organ Class (SOC) % n % n 44% 4 78% 7 Uveitis Eye disorders 0% 0 11% 1 Eye oedema Eye disorders 0% 0 11% 1 Conjunctival hyperemia Eye disorders 0% 0 11% 1 Eye inflammation Eye disorders Adverse reactions (events associated with VCN - 01, monotherapy) Number events VCN - 01 Relatedness Description/Nature of the event (MedDRA PT) MedDRA System Organ Class (SOC) 3 Related Uveitis Eye disorders 1 Non - related Retinal detachment Eye disorders 1 Non - related Vitreous and anterior chamber haemorrhage Eye disorders 1 Non - related Enucleation Eye disorders Serious Adverse Events Staining of VCN - 01 viral proteins in healthy retina Patient #2 (germline mutation) Conserved retina Calcified tumor area Conserved retina Tumor area Conserved retina Tumor area Conserved retina Necrotic tumor Patient #9 (germline mutation) Patient #8 (germline mutation) Patient #1 Other safety evidences: • No evidence of extraocular relapse • No systemic toxicities occurred. • VCN - 01 caused changes in electroretinograms due to turbidity, but they were reversible • 2 doses of VCN - 01 at 2E+10 vp/eye was defined as the RP2D • From the second patient onwards, all patients received pre - emptive oral and/or topical steroids to prevent uveitis. Uveitis was improved or resolved at day 42 in most patients. • One patient with G3 uveitis did not receive the second dose because of medical decision and also experienced glaucoma requiring treatment. VCN - 01 does not replicate in healthy retinal tissue of patients with either somatic or germline Rb mutation No DLT observed Preliminary E fficacy Evaluation Status at Enucleation Enucleation Date Final RB_RECIST Response at D42 Vitreous seed response after Dose 2 Tumor response after Dose 2 Vitreous seed response after Dose 1 Tumor response after Dose 1 Number of doses Patient (dose) Tumor progression D44 SD SD SD SD SD 2 #1 (2.0x10 9 vp) Tumor progression D62 PR PR PR PR PR 2 #2 (2.0x10 10 vp) n.a No PR PR SD PR PR 3 #4 (2.0x10 10 vp) Lack of response D56 SD SD SD SD SD 2 #5 (2.0x10 10 vp) Tumor progression D170 PR PR SD PR SD 2 #8 (2.0x10 10 vp) Tumor progression D37 PD SD SD SD SD 2 #9 (2.0x10 10 vp) n.a No PR PR - PR - 2 #11 (2.0x10 10 vp) n.a No PR - - PR PR 1 #12 (2.0x10 10 vp) Tumor progression D93 SD SD SD SD SD 2 #13 (2.0x10 10 vp) Expected enucleation w/o response: D37 - 43; Subsequent eye - conservative treatment was administered to patients #4, #8, #11, #12 and #13 Analysis of VCN - 01 presence on biological samples Active Tumor (vitreous seeds) • 3 - years old • Bilateral retinoblastoma (with germline Rb 1 mutation), with 1 st eye already enucleated . • Previous treatments : • Systemic chemotherapy CBP/VP - 16 /VCR (followed by intraarterial dosing of topotecan/melphalan) . • Tumor relapse 9 months later Intravitreous melphalan : NO RESPONSE . Calcified Tumor (from previous treatments) D0 (pre - injection) D28 D64 D189 D240 Case - study Patient #3 • Absence of VCN - 01 genomes in blood . Persistence of VCN - 01 genomes in aqueous humor correlates with vitreous seed presence . Our more since appreciation to the patients and their families that participated in this trial. This work has been partially funded by Cure4RB Project – RETOS 2015 (MiNECO, Spain) 5 patients with partial response, 3 with stable disease and 1 with progressive disease. The eyes of 3 out of 5 patients with PR are preserved with vision after receiving eye - conservative therapy (follow - up 12 - 49 mont hs)