Inclusion Criteria:

- The patient has radically resected NSCLC.

- The NSCLC is of pathological stage IA-T1b, IB, II or IIIA NSCLC. The surgical
technique for resection of the patient's tumor is anatomical, involving at least a
segmentectomy. The patient's tumor shows expression of PRAME.

- The patient is ≥ 18 years of age at the time of first consent.

- Written informed consent has been obtained from the patient prior to performance of
any study-specific procedure.

- The patient is free of disease (no residual tumor, no loco-regional recurrence, no
distant metastasis), as confirmed by a post- thoracic surgery contrast-enhanced
computed tomography (CT scan) of the chest, upper abdomen and by a contrast-enhanced
CT scan or Magnetic Resonance Imaging (MRI) of the brain. Other examinations should
be performed as clinically indicated.

- Eastern Co-operative Oncology Group (ECOG) performance status of 0, 1 or 2 at the
time of randomization.

- Adequate bone-marrow reserve, adequate renal, hepatic and adrenal function as
assessed by standard laboratory criteria.

- If the patient is female, she must be of non-childbearing potential, i.e. have a
current tubal ligation, hysterectomy, ovariectomy or be post-menopausalor if she is
of childbearing potential, she must practice adequate contraception for 30 days prior
to administration of study product, have a negative pregnancy test and continue such
precautions during all study treatment period and for 2 months after last treatment
administration.

- Patients who the investigator believes can and will comply with the requirements of
this protocol (e.g. return for active follow-up visits).

Exclusion Criteria:

- The patient is diagnosed with a concomitant malignancy and/or has a history of
malignancy within the past five years or has had a malignancy that has been in
complete remission for less than 5 years. Patients with effectively treated non -
melanoma skin cancers or effectively treated carcinoma in situ of the cervix both of
which in remission for less than 5 years will be eligible.

- The patient has received any anti-cancer specific treatment, including radiotherapy,
immunotherapy, hormonal therapy, chemotherapy or neo-adjuvant chemotherapy, except
for:

- Administration of adjuvant platinum-based doublet chemotherapy for the treatment
of the current NSCLC allowed between surgery and randomization.

- Treatment of previous malignancies as allowed by the protocol.

- The patient has been diagnosed with a Potential Immune-Mediated Disease (pIMD).
Patients with vitiligo are not excluded from the study.

- The patient has a history of confirmed adrenal dysfunction.

- The patient requires concomitant treatment with any immunosuppressive agent, or with
systemic corticosteroids prescribed for chronic treatment (more than 7 consecutive
days).

- The patient needs chronic long term oxygen therapy (LTOT). The patient has medically
uncontrolled congestive heart failure or hypertension, unstable heart disease or
uncontrolled arrhythmia at the time of randomization.

- The patient has an uncontrolled bleeding disorder.

- The patient has undergone splenectomy.

- The patient is known to be Human Immunodeficiency Virus (HIV)-positive.

- The patient has psychiatric or addictive disorders that may compromise his/her
ability to give informed consent, or to comply with the trial procedures.

- The patient has other concurrent severe medical problems, unrelated to the
malignancy, that would significantly limit full compliance with the study or expose
the patient to unacceptable risk.

- The patient has a history of allergic disease or reactions likely to be exacerbated
by any component of the study investigational product.

- The patient has received any investigational or non-registered product within the 30
days preceding randomization, or planned use during the study period.

- For female patients: the patient is pregnant or lactating or is planning to become
pregnant.