A Double Blind, Randomized Controlled Study, Evaluating the Safety and Efficacy of RD2 Ver.02 For the Management of Anal Fistulas

Inclusion Criteria:

• Subject is ≥18 years of age

• Subject has a transsphincteric or long intersphincteric anal fistula (>1.5 cm), witha seton in place for a minimum of 1 month, deemed eligible for primary or repeatfistula repair by anorectal advancement flap or LIFT: Anterior, posterior or lateralfistula, first or recurrent, at any position circumferentially, with one externalopening and one internal opening, involving >20% of anal sphincter.

• Subjects is unable or unwilling to receive invasive surgical procedures, anorectaladvancement flap or LIFT procedure, and is opting for minimally invasive techniqueof anal fistula management (i.e., fistula tract debridement and suturing of internalopening).

• Prior to enrollment, during the preceding 3 months subject must undergo a pelvic MRIto document intersphincteric or transsphicnteric fistula and absence of underlyingabscess

• Female subjects who are capable of conceiving and all males capable of inseminationmust use an acceptable form of contraception in order to participate in the studyand for 6 months following study procedure (acceptable forms of contraceptioninclude condoms for males and contraceptive pills or IUDs for women)

Exclusion Criteria:

• Subject who has a life expectancy of less than 24 months.

• Subjects who are cognitively impaired and have a healthcare proxy or those who arecognitively impaired and clearly do not understand the contents of the informedconsent form.

• Cannot withdraw blood in the required amount (up to 15 mL).

• Women who are pregnant or currently breast feeding.

• Subject is currently receiving (i.e., within the past 30 days) or scheduled toreceive systemic steroids (more than 10mg per day).

• Multiple fistula tracts, as confirmed on pelvic MRI

• Short fistula tract that in the surgeon's opinion are amenable to fistulotomy

• Active infection including perianal infection, and/or any active systemic or localinfection.

• Presence of a perirectal abscess on pelvic MRI

• Presence of dominant luminal active Crohn's disease, validated by recent colonoscopyfrom preceding 12 months, requiring immediate therapy

• Rectal and/or anal stenosis and / or active proctitis, if this means a limitationfor any surgical procedure.

• Known allergies or hypersensitivity to any of the following: antibiotics includingbut not limited to penicillin, streptomycin, gentamicin, aminoglycosides; HumanSerum Albumin (HSA); Dulbecco Modified Eagle's Medium (DMEM); materials of bovineorigin; local anaesthetics or gadolinium (MRI contrast); Known hypersensitivity toreagents and components of RD2 Ver.02 including calcium gluconate, Kaolin or citrateand ethylene oxide.

• Contraindication to MRI scan, (e.g., due to the presence of pacemakers, hipreplacements, or severe claustrophobia).

• Known coagulation problems, abnormal thrombocytes level or if heparin is givenintravenously. Subjects who are taking Coumadin, Aspirin, Plavix (Clopidogrel),Eliquis or Pradaxa will not be excluded.

• Patients with increased risk for the surgical procedure or major alteration of anyof the following laboratory tests:

Serum Creatinine levels >1.5 upper limit of normality (ULN) Total bilirubin >1.5 ULN (unless predominantly non conjugated due to documented history of Gilbert's syndrome) AST/ ALT >3.0 ULN Hemoglobin <10.0 g/dL Platelets <150.0 x109/L Albuminemia <3.0 g/dL.

• Patients who do not wish to or cannot comply with study procedures.

• Patients currently receiving or having received within 12 months prior to enrolmentinto this clinical study, any investigational drug.

• Subjects who need surgery in the perianal region for reasons other than fistulas atthe time of inclusion in the study, or for whom such surgery is foreseen in thisregion in the 24 weeks after treatment administration.

• Contraindication to the anesthetic procedure.

• Subject with a diagnosis of Ulcerative Colitis

• Subject with malignancy, undergoing active treatment

• Rectovaginal fistula

• History of pelvic radiation