An open-label Phase III study of arfolitixorin vs leucovorin in modified FOLFOX-6 for first-line treatment of metastatic colorectal cancer Heinz-Josef Lenz,1 Peter Gibbs,2 Sebastian Stintzing,3 Volker Heinemann,4 Gerald W. Prager,5 Peter Nygren,6 Christos A. Papadimitriou,7 Roger Tell,8 Takayuki Yoshino,9 Derek J. Jonker,10 Aimery de Gramont,11 Josep Tabernero12

1University of Southern California, Los Angeles, CA, USA; 2Western Health, Melbourne, Australia; 3Charité – Universitätsmedizin Berlin, Berlin, Germany; 4Klinikum der Universität München, München, Germany; 5Medical University of Vienna, Vienna, Austria; 6Uppsala University, Uppsala, Sweden; 7Aretaieion Hospital, Athens, Greece; 8Isofol Medical AB, Gothenburg, Sweden; 9National Cancer Center Hospital East, Chiba, Japan; 10Ottawa Hospital Research Institute, Ottawa, ON, Canada; 11Franco-British Hospital, Levallois-Perret, France; 12Vall d’Hebron University Hospital and Institute of Oncology, Barcelona, Spain

BACKGROUNDCurrent treatments and folate-based strategies• First-line treatment of metastatic colorectal cancer (mCRC) is typically with cytotoxic chemotherapy, combined with biologics such as bevacizumab,

cetuximab, or panitumumab1 • 5-fluorouracil(5-FU),co-administeredwiththefolateleucovorin,isanestablishedcornerstoneofmCRCtreatment.15-FUundergoesmetabolictransformation

to5-fluorodeoxyuridinemonophosphate(FdUMP),whichpotentlyinhibitsthethymidylatesynthaseenzyme,inturndisruptingDNAsynthesisandrepair, and resulting in cell death in rapidly proliferating tumor cells (Figure 1)2

• Foreffective5-FUinhibitionofthymidylatesynthase,folatesareco-administeredtoformastableternarycomplexofFdUMP,[6R]-5,10-methylenetetrahydrofolate(MTHF),andthymidylatesynthase3

• AllfolatescurrentlyapprovedforclinicaluseinpatientswithmCRCareprodrugsthatneedtobemetabolicallyactivatedto[6R]-MTHF,theactivethymidylatesynthasecofactorthatpotentiatestheeffectof5-FU(Figure 2)4

Mechanism of action of arfolitixorin• Arfolitixorinconsistsoftheactivecofactor[6R]-MTHFandthereforedoesnotrequiremulti-stepmetabolicactivation4 • Responseto5-FU/leucovorinmaybeimpairedbylowexpressionoffolate-activatinggenesduetoinsufficientlevelsofcofactorand,consequently,

weak inhibition of thymidylate synthase5,6

• Excess[6R]-MTHF,however,favorscompetitionatthethymidylatesynthasebindingsiteforFdUMPoverdeoxyuridinemonophosphate(dUMP), potentiallypermittingmoreextensiveandprolongedenzymeinhibitionfollowing5-FUtreatment(Figure 1)4

Arfolitixorin clinical data• InthePhaseI/IIpharmacokineticsstudyISO-CC-002,considerablyhigherintratumoralandintramucosalconcentrationsof[6R]-MTHFwereachievedin

patientsreceivingasingleintravenousdoseofarfolitixorincomparedwithlevoleucovorin,ateitheroftwoequimolardoselevels,whichisconsistentwith thepotentialforgreaterefficacyofarfolitixorin7

• PreliminarydatafromthePhaseI/IIstudyISO-CC-005,whichevaluatedtheefficacyofarfolitixorin/5-FU,aloneorincombinationwithirinotecan oroxaliplatin,andwithorwithoutbevacizumab,reportedearlytumorshrinkagein47%offirst-linepatientsafter8weeks.8Afterupto32weeks offollow-up,preliminaryoverallresponserate(ORR)wasachievedin58%ofpatients.8Themostfrequentlyreportedadverseeventsweretypicalchemotherapysideeffects,includingfatigue,nausea,neutropenia,diarrhea,vomiting,andneuropathy9

Phase III evaluation of arfolitixorin• EvaluationofarfolitixorininalargerrandomizedPhaseIIIclinicalsettingisrequiredtovalidateandextendthesedata

STUDY COUNTRIESTheAGENTstudywilltakeplace acrossmorethan100sitesin the following countries (Figure 4):

• Australia

• Austria

• Canada

• France

• Germany

• Greece

• Japan

• Spain

• Sweden

• USA

STUDY DATESKey study milestones (Figure 5):

• Firstpatientin:December18,2018

• Interimanalysis:Q32020

• FinalPFSdata:Q32021

• FinalOSdata:TBD

STUDY RATIONALE• It is hypothesized that the administration of arfolitixorin

will result in higher intracellular concentrations of the activethymidylatesynthasecofactor[6R]-MTHFinallpatients compared with leucovorin administration, with less inter- and intra-individual variability

• Inturn,thismaytranslatetoimprovedclinicalefficacyin5-FUtreatmentofmCRC

STUDY DESIGN• Thisisarandomized,multicenter,parallel-group,PhaseIIIstudyAGENT(NCT03750786)

tocomparetheefficacyofarfolitixorinrelativetothatofleucovorininpatientswithmCRCtreatedwith5-FU,oxaliplatin,andbevacizumab10

• Patientswillberandomizedina1:1ratiotoeithertheinvestigationalarm(arfolitixorin +5-FU+oxaliplatin[ARFOX]+bevacizumab)orthecomparatorarm(leucovorin+5-FU +oxaliplatin[modifiedFOLFOX-6]+bevacizumab),andtreateduntiloccurrenceofdiseaseprogressionbasedonResponseEvaluationCriteriainSolidTumors1.1criteria(Figure 3) or unacceptable toxicity

Key inclusion and exclusion criteria are listed in Table 1.

Contact: Professor Heinz-Josef Lenz, email: lenz@med.usc.edu Acknowledgements: This study is funded by Isofol Medical AB (publ). Medical writing assistance was provided by Shelley Morris of Syneos Health, UK, and funded by Isofol Medical AB (publ).

Table 1. Key eligibility criteria

PATIENTS• Targetrecruitmentincludesrandomizationof

440patientsin18monthsandiscurrentlyongoing (Figure 4).Anadaptivestudydesign,intendedtoensuresufficientstatisticalpowerwhileminimizingpatient numbers, includes the possibility to increase thesamplesizeto660patients,asdeterminedby theDataandSafetyMonitoringBoardduringtheinterimanalysistobecarriedoutafter330patients haveundergonetheir16-weekscan(Figure 3)

STUDY ENDPOINTS• TheprimarystudyendpointwillbeORRbyblindedindependentcentralreview,

definedasthebestresponsefromthestarttotheendofstudytreatment(Figure 3) • Keysecondaryendpointswillincludeprogression-freesurvival(PFS),definedastime

fromrandomizationtofirstoccurrenceoftumorprogressionbasedoncomputerizedtomographyscans/magneticresonanceimagingordeath,anddurationofresponse (DoR),measuredfromwhenmeasurementcriteriaarefirstmetforcompleteresponse/partialresponseuntilprogressivediseaseisfirstobjectivelydocumented

• Additionalsecondaryendpointsincludeoverallsurvival(OS),qualityoflife,safety and tolerability, and patients undergoing curative metastasis resection

REFERENCES1.VanCutsemE,etal.AnnOncol2016;27:1386–422;2.KlineCLB,etal.Pharmaceuticals2013;6:988–1038;3.GustavssonB,etal.ClinColorectalCancer2015;14:1–10; 4.DanenbergPV,etal.CritRevOncolHematol2016;106:118–31;5.OdinE,etal.MolMed2015;21:597–604;6.GustavssonB,etal.PosterpresentationatASCO2018Congress.Posterno.3550(#43);7.WettergrenY,etal.CancerChemotherPharmacol2015;75:37–47;8.Isofol.Pressrelease,May2019.Availableat:https://isofolmedical.com/ news-press/?detail=8DE31DA3DD13C740.LastaccessedSeptember2019;9.CarlssonG,etal.PosterpresentationatESMO2018Congress.Posterno.569P; 10.ClinicalTrials.gov.Availableat:https://clinicaltrials.gov/ct2/show/NCT03750786.LastaccessedSeptember2019.

SUMMARY• IncontrasttofolatescurrentlyapprovedtotreatmCRC,arfolitixorindoesnotrequiremetabolicactivationandmayproducehigherandmoreconsistent

concentrationsof[6R]-MTHFthanthecomparatorleucovorin,whichmayinturnimproveclinicalefficacy• ThisPhaseIIIstudywillcomparetheefficacyoffirst-linearfolitixorinversusleucovorinincombinationwith5-FU,oxaliplatin,andbevacizumabinpatients

with mCRC• TheprimaryendpointwillbeORRandkeysecondaryendpointswillincludePFSandDoR• AtranslationalprogramwillexploretherelationshipbetweenexpressionlevelsofkeygenesinvolvedinfolatemetabolismandtransportinmCRCtumor

biopsies,andtreatmentefficacy• InterimdataareanticipatedinQ32020(Figure 5)

EXPLORATORY ANALYSES• Atranslationalprogramwilldeterminefolatemetabolism-andtransportation-relatedgeneexpressionlevelsinallpatients• Fixed-formalinparaffin-embeddedmCRCtumorsectionsderivedfrombiopsiesobtainedpriortotreatmentinitiationwillbeusedforgeneexpression

analysisviaavalidatedtechniquetobeconductedatacentralaccreditedlaboratoryinGothenburg,Sweden• Levelsofthefollowinggeneswillberetrospectivelyanalyzed:adenosinetriphosphate(ATP)-bindingcassetteC3transporter,methylenetetrahydrofolate

dehydrogenase2,proton-coupledfolatetransporter,serinehydroxymethyltransferase1,peptidylprolyl-isomeraseA,andbeta-actin

5-FU, 5-fluorouracil; CT, computerized tomography; ECOG, Eastern Cooperative Oncology Group; mCRC, metastatic colorectal cancer; MRI, magnetic resonance imaging; PS, performance status.

KEY ELIGIBILITY CRITERIA

Inclusion

• Adults≥18yearsofage• Colorectaladenocarcinomaverifiedbybiopsy • Availabilityofbiopsymaterial,fromtheprimary

tumor or metastasis, allowing for analysis of tumor gene expression

• Non-resectablemCRCplannedforfirst-linetherapywithleucovorin,5-FU,oxaliplatin,andbevacizumab

• Evaluabledisease(viaCTscanorMRI)• ECOGPS0or1• Adequatehematologicfunction • Adequatehepaticfunction • Adequaterenalfunction

Exclusion

• Malignanttumorsotherthancolorectal adenocarcinomas

• <6monthssincelastanti-cancertreatment• Knowndihydropyrimidinedehydrogenasedeficiency• Clinicallysignificantcardiovasculardisease• Central nervous system metastases

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ASCO-GI Congress 2020. Poster no. TPS268

ORR, overall response rate; OS, overall survival; PFS, progression-free survival.

• Non-resectable mCRC

• Eligible for 5-FU, oxaliplatin, and bevacizumab therapy

• ECOG PS 0 or 1 Stratification factors:• Geographic region• Primary tumor location• Previous neo-adjuvant/ adjuvant treatment

Randomization 1:1

ARFOX: arfolitixorin, 60 mg/m2 IV bolus twice (total 120 mg/m2); 5-FU, 400 mg/m2 IV bolus, 2,400 mg/m2 IV infusion;

oxaliplatin, 85 mg/m2 IV infusion + bevacizumab, 5 mg/kg IV infusion

Interim analysis: first ~330 patients

Patients

n=440

mFOLFOX-6: leucovorin, 400 mg/m2 IV infusion; 5-FU, 400 mg/m2 IV bolus, 2,400 mg/m2 IV infusion;

oxaliplatin, 85 mg/m2 IV infusion+ bevacizumab, 5 mg/kg IV infusion

Disease progression

Disease progression

Primary endpointORR

Key secondary endpointsPFSDoR

Additional secondary endpointsOS

QoLSafety and tolerability

Patients undergoing curative metastasis resection

5-FU, 5-fluorouracil; ARFOX, arfolitixorin, 5-FU, and oxaliplatin; DoR, duration of response; ECOG, Eastern Cooperative Oncology Group; IV, intravenous; mCRC, metastatic colorectal cancer; mFOLFOX-6, modified FOLFOX-6 (leucovorin, 5-FU, and oxaliplatin); ORR, overall response rate; OS, overall survival; PFS, progression-free survival; PS, performance status; QoL, quality of life.

Figure 3. Study design and planned analyses

Final analysis (ORR and PFS)

Figure 5. Key study milestones

5-FU metabolite competes to inhibit TS (and DNA synthesis), Arfolitixorin stabilizes 5-FU metabolite to inhibit TS (and block DNA synthesis)

5-FU FdUMP FdUMPTS-substrate

(dUMP)

5-FU displaced due to MTHF shortage

Thymidineshortage

Normalized thymidineavailability

NormalDNA synthesis

Tumor cell survival

Arrested DNA synthesis

Tumor cell death Tumor cell death

ARFOLITIXORIN

Persistent thymidine shortage

Persistent DNA synthesis arrest

5-FU FdUMPTS-substrate

(dUMP)TS-substrate

(dUMP)

TS TS TS

5-FU, 5-fluorouracil; dUMP, deoxyuridine monophosphate; FdUMP, 5-fluorodeoxyuridine monophosphate; MTHF, [6R]-5,10-methylenetetrahydrofolate; TS, thymidylate synthase.

Figure 4. Sites participating in the AGENT study

Figure 2. Multi-step activation of folates

Figure 1. Mechanism of action of arfolitixorin

5-FU, 5-fluorouracil; THF, tetrahydrofolate.

ISO01045_Isofol_AGENT_ENCORE_Clinical_Poster_for_ASCO_Dec_2019_1144x2363_Fa1b.indd 1ISO01045_Isofol_AGENT_ENCORE_Clinical_Poster_for_ASCO_Dec_2019_1144x2363_Fa1b.indd 1 21/01/2020 16:2721/01/2020 16:27