A Safety and Efficacy Study of CC-122 in Combination With Nivolumab in Subjects With Unresectable Hepatocellular Carcinoma (HCC)

Study population included subjects who had progressed after or were intolerant to no more
than 2 previous systemic therapies for unresectable HCC, or are naïve to systemic therapy.

The dose escalation part of the study was designed to explore three dose levels of CC-122 to
identify the recommended phase 2 dose (RP2D) to be used in the expansion phase. Approximately
20 subjects were to be enrolled in the dose escalation part of the study. Subjects could be
treated for up to 2 years, or until progression of disease, unacceptable toxicity,
subject/physician decision, withdrawal of consent, death. Safety follow up until 28 days
after CC122 treatment and 90 days after nivolumab treatment. RECIST 1.1 criteria was used to
determine response. Survival follow up until death, withdrawal of consent, or the study
closes. Subjects were permitted to continue treatment beyond progression (TBP) if they
continue to meet protocol criteria, had stable performance status, had clinical benefit,
other treatment options were discussed. A separate ICF was signed to continue TBP.

During the dose escalation phase, CC-122 was administered orally 5 consecutive days out of 7
(5 days on/2 days off weekly) on Days 1 to 5, 8 to 12, 15 to 19 and 22 to 26 of each 28-day
cycle. Once the RP2D for dosing of CC-122 in combination with nivolumab was defined,
expansion (Phase 2) would start. A modified 3+3 dose escalation design was used to identify
the initial toxicity of the combination. Up to six subjects were concurrently enrolled into a
dose level. Decisions as to which dose level to enroll a new subject were based on the number
of subjects enrolled and evaluable, the number of subjects experiencing DLTs, and the number
of subjects enrolled but who are not yet evaluable for toxicity in the current cohort at the
time of new subject entry. A Safety Review Committee (SRC) comprised of investigators
participating in the study made dose escalation decisions based on these criteria.

After completion of the Dose Escalation Phase, the Dose Expansion Phase of the study did not
proceed due to the changing landscape in the treatment of HCC. There were no additional
safety concerns or safety signals identified in the dose escalation phase of the study.

Inclusion Criteria:

- Subjects must satisfy the following criteria to be enrolled in the study:

- Subject is ≥ 18 years of age at the time of signing the informed consent form (ICF)

- Subject has a confirmed pathologic diagnosis of Hepatocellular carcinoma (HCC)
according to the American Association for the Study of Liver Diseases (AASLD)
Guidelines.

- Subjects who have progressed after or were intolerant to no more than 2 previous
systemic therapies for unresectable HCC, or are naïve to systemic therapy.

- Subject has at least one measurable lesion according to RECIST 1.1.

- Subject has a life expectancy of ≥ 12 weeks

- Subject has an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 or
1

- Subject has adequate hematologic function and adequate hepatic function at screening

Exclusion Criteria:

- The presence of any of the following will exclude a subject from enrollment:

- Subject has received more than 2 previous systemic therapies for Hepatocellular
carcinoma (HCC).

- Subject has received previous treatment with any anti-PD-1 (Programmed death 1) or
anti-PD-L1 (PD-1 ligand receptor) antibody