This is a randomized, double-blind, placebo controlled, safety, tolerability, and pharmacokinetic dose escalation Phase II study of DFA-02 in patients undergoing colorectal surgery to evaluate the safety, tolerability and pharmacokinetics of DFA-02.

Despite antibiotic prophylaxis and improvements in surgical techniques, surgical site infections (SSI) still occur. DFA-02 is a novel bioresorbable modified release gel containing both gentamicin and vancomycin to be applied during surgical incision closure for the prevention of surgical site infections (SSIs) in patients undergoing colorectal surgery.

Inclusion Criteria:

1. Males and females 18 years of age or older;

2. If female, the patient must be:

   • postmenopausal (if amenorrheic for < 1 year, postmenopausal status must be confirmed by an elevated follicle stimulating hormone [FSH] level > 30 mIU/mL; if amenorrheic for > 1 year, FSH level not required);
   • surgically sterilized (does not have a uterus or has had bilateral tubal ligation); or
   • if of child-bearing potential, she must have a negative serum pregnancy test on entry in the study, and agree to use adequate birth control during the study and for 30 days after the administration of study agent. Medically acceptable contraceptives include: (1) surgical sterilization (such as a tubal ligation or hysterectomy), (2) approved hormonal contraceptives (such as birth control pills, patches, implants or injections), (3) barrier methods (such as a condom or diaphragm) used with a spermicide, or (4) an intrauterine device (IUD);

3. BMI 25-40, inclusive;

4. Scheduled to undergo nonemergent colorectal surgery involving a laparotomy incision of 7 cm or greater (hand-assisted laparoscopic surgery is allowed). List of eligible procedures: left, right or transverse colectomy, segmental/sleeve left colon resection, total abdominal colectomy with ileorectal anastomosis, total abdominal colectomy with ileostomy, total abdominal proctocolectomy, low anterior resection, sigmoid resection, non-emergent Hartmann's procedure, colotomy with polypectomy distal to hepatic flexure, colostomy takedown through laparotomy (not peristomal) incision, ileo-pouch anal anastomosis, abdominal perineal resection of the rectum;

5. Willing and able to give informed consent;

6. Available for evaluation from baseline until final evaluation at 30 days post surgery.

Exclusion Criteria:

1. Known history of hypersensitivity to gentamicin or vancomycin, other aminoglycoside antibiotics or the excipients of the study products (soy bean products or sesame oil);
2. Emergency surgery (urgent surgery is allowed if informed consent is obtained and the study procedures can be performed);
3. Significant concomitant surgical procedure (Note: concomitant appendectomy, cholecystectomy, oophorectomy, and liver biopsy/wedge resection are allowed);
4. Prior laparotomy within the last 60 days of this planned procedure;
5. Planned second laparotomy or colorectal surgical procedure (e.g. colostomy or ileostomy takedown) within 30 days of this planned first procedure;
6. Expectation that a surgical drain will be placed;
7. Preoperative sepsis, severe sepsis, or septic shock;
8. Abdominal wall infection/surgical site infection from previous laparotomy/laparoscopy or for any reason;
9. Active systemic infection or systemic (oral or intravenous) antibiotic therapy within the 1 week prior to the date of surgery other than specified preoperative antimicrobial prophylaxis (Note: single dose antibiotic therapy for dental or other minor procedures is allowed as is the use of oral non-absorbable antibiotics for preoperative bowel decontamination);
10. Requirement for gentamicin or vancomycin preoperative antimicrobial prophylaxis (Note: systemic antibiotic therapy within 72 hours after surgery with gentamicin or vancomycin must be avoided and any systemic antibiotic therapy during that time should be discussed with the Coordinating Center PI or Medical Monitor);
11. Requirement for concomitant use or use during the 30 days prior to Day 1 of any prescription or OTC drug that would interfere with the study or place the patient at undue risk. Concurrent systemic or topical use of other potentially neurotoxic, nephrotoxic, and/or ototoxic drugs, such as gentamicin, cisplatin, cephaloridine, kanamycin, amikacin, polymyxin B, colistin, paromomycin, streptomycin, tobramycin, vancomycin, ethacrynic acid, furosemide, and viomycin, should be avoided;
12. Preoperative evaluation suggests an intra-abdominal process that might preclude full closure of the skin;
13. Ongoing treatment (e.g. chemotherapy, radiation) for non-colorectal cancer;
14. History of significant drug or alcohol abuse within the past year;
15. Serum Creatinine > 1.3 mg/dL
16. Serum Bilirubin > 2.5 times upper limit of normal;
17. History of uncontrolled diabetes mellitus (controlled diabetic patients whose hemoglobin A1c is ≤ 9.0% may be included);
18. Patients who are immunocompromised including but not limited to systemic corticosteroid use or chemotherapy/radiation during the 30 days prior to surgery, organ transplantation, or HIV infection (Note: inhaled corticosteroids are not exclusionary and single dose use of corticosteroids to prevent PONV is allowed.);
19. Any clinically meaningful hearing loss (from Medical History);
20. Clinically exclusionary results on clinical laboratory, ECG, or physical examination including but not limited to positive hepatitis B or C or HIV;
21. Pregnant or lactating, or if of childbearing potential not practicing a birth control method with a high degree of reliability;
22. Refusal to accept medically indicated blood products;
23. Participation within 30 days before the start of this study in any experimental drug or device study, or currently participating in a study in which the administration of investigational drug or device within 60 days is anticipated;
24. Patients with anterior abdominal wall mesh that is not planned to be completely removed during the planned procedure;
25. Unable to participate in the study for any reason in the opinion of the Principal Investigator;
26. Postsurgical life expectancy of less than 30 days, in the Investigator's or Sponsor's opinion;
27. Expected discharge from the hospital less than 3 days after surgery.

From Informed Consent to 30 Days After Surgery

Protocol specified cohorts of 10, 20, 30 or 40 mL to be placed after closure of the fascia and prior to skin closure. Experience with 20 and 30 mL dose levels showed that even largest patients would not accommodate 40 mL so that arm was not done.