Study of SC-003 Alone and in Combination With ABBV-181 in Subjects With Platinum-Resistant/Refractory Ovarian Cancer

Phase 1a is a dose escalation study in patients with histologically/cytologically confirmed
ovarian cancer that are platinum-resistant or refractory. Phase 1b is an expansion study
where patients will be enrolled and treated at recommended dose and schedule based on the
Phase 1a.

Inclusion Criteria:

- Histologically or cytologically confirmed ovarian epithelial cancer

- Evidence of progressive disease (PD) on or within 6 months of a platinum (cisplatin or
carboplatin) regimen: at least 1 prior regimen must have contained a platinum-taxane
combination

- Measurable disease as defined by RECIST 1.1

- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

- Fresh or archived tumor tissue sample available for target expression analysis. [Phase
1b only: Subjects' tumor tissue must test positive for target expression.]

- Adequate hematologic and organ function as confirmed by laboratory values

- At least 3 weeks between last systemic chemotherapy and planned start of study
treatment (4 weeks for prior investigational drugs, immunotherapy, radiotherapy, or
biologics) for ovarian cancer

- At least 3 weeks between major surgery and planned start of study treatment; major
incisions must have healed

Exclusion Criteria:

- History of prior malignancy, with the exception of the following: malignancy treated
with curative intent and with no evidence of active disease present for more than 3
years prior to screening and felt to be at low risk for recurrence by treating
physician; or adequately treated lentigo maligna melanoma without current evidence of
disease or adequately controlled non-melanomatous skin cancer; or adequately treated
cervical carcinoma in situ without current evidence of disease.

- Uncontrolled infection requiring systemic antibiotics/antivirals/antifungals

- Evidence of complete or partial bowel obstruction

- Patients requiring IV hydration or parenteral nutrition

- Positive pregnancy test in females of child-bearing potential or pregnant or currently
breastfeeding

- Known hypersensitivity to any component of study drug including potential subjects
with a history of major immunologic reaction to any IgG-containing agent

- Inability to tolerate premedication with dexamethasone

- Uncontrolled cardiac disease, or myocardial infarction within the last 12 months, or
left ventricular ejection fraction (LVEF) < 50%, or QTcF interval > 470 msec

- Class II, III or IV heart failure as defined by the NYHA functional class system

- Positive serology for hepatitis B or C, or known human immunodeficiency virus
infection (HIV)

- Previous treatment with a pyrrolobenzodiazepine (PBD)-based drug

Additional exclusion criteria for the SC-003 and ABBV-181 combination treatment regimen:

- History of inflammatory bowel disease

- Active autoimmune disease, with exceptions of psoriasis not requiring systemic
treatment, vitiligo, type 1 diabetes mellitus and hypothyroidism

- History of primary immunodeficiency, allogeneic bone marrow transplantation, solid
organ transplantation, or previous clinical diagnosis of tuberculosis

- History of immune-mediated pneumonitis

- Current or prior use of immunosuppressive medication within 14 days prior to the first
dose of study treatment