Near-infrared fluorescence-guided oncologic surgery (EGOS) with the use of a tumor specific tracer (SGM-101) developed by Surgimab can provide valuable intra-operative information about tumor location and extensiveness, which can be difficult to detect with conventional visual and tactile feedback. Hence, this information could aid in intra-operative decision making and therewith foster complete resection margins and less extensive surgery. Subsequently, this may drastically improve patient care by improving oncologic outcome.

Inclusion Criteria:

1. Patients aged over 18 years old;
2. All women of child bearing potential and all males must practice effective contraception during the study and be willing and able to continue contraception for at least 30 days after their last dose of study treatment.
3. Patients should be scheduled and eligible for surgery because of a clinical diagnosis of T3 with a threatened CRM or T4 rectal cancer (locally advanced) or recurrent rectal cancer. (UICC. TNM classification of diseases for oncology. 3rd ed. Geneva: World Health Organization; 2000)
4. Patients should be capable and willing to give signed informed consent before study specific procedures.

Exclusion Criteria:

1. Other malignancies, either currently or in the past five years, except adequately treated in situ carcinoma of the cervix and basal or squamous cell skin carcinoma.

2. Patients with a history of, or recently diagnosed with, peritoneal metastases (even those diagnosed during surgery)

3. Patients with a recent history (within the last 3 years) of other distant metastases (even those diagnosed during surgery)

4. Patient with a history of a clinically significant allergy.

5. Patients pregnant or breastfeeding lack of effective contraception in male or female patients with reproductive potential;

6. Laboratory abnormalities defined as:

   1. Aspartate AminoTransferase, Alanine AminoTransferase, Gamma Glutamyl Transferase) or Alkaline Phosphatase levels above 5 times the or;
   2. Total bilirubin above 2 times the ULN or;
   3. Serum creatinine above 1.5 times the ULN or;
   4. Platelet count below 100 x 109/L or;
   5. Hemoglobin below 4 mmol/L (females) or below 5 mmol/l (males);
   6. Known positive test for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAG) or hepatitis C virus (HCV) antibody or patients with untreated serious infections;

7. Any condition that the investigator considers to be potentially jeopardizing the patients' well-being or the study objectives.

8. Previous administration of SGM-101