Inclusion Criteria:

- ≥18 years of age

- Histologically or cytologically confirmed diagnosis of NSCLC

- Stage II/III non-operable disease, without malignant pleural effusion

- Presence of at least one measurable target lesion

- Acceptable pulmonary function as defined by a Fev1 of ≥30% and a DLCO of ≥ 40% of
predicted,

- NYHA I-II functional status

- Expected risk of radiation-induced pulmonary toxicity is modest: MLD ≤ 20 and maximum
cord dose 50 Gy

- WHO performance 0-1

- Life expectancy of at least 6 months

- Adequate hematological, renal and hepatic functions

- Hemoglobin ≥ 5.5 mmol/l

- Leucocytes > 3.0 x 109/l

- Absolute neutrophil count > 1.5x109/l

- Platelet count > 100 x 109/l

- Total bilirubin < 1.5 x UNL

- ASAT/ALAT < 2.5 x UNL

- Alkaline phosphatase < 5 x UNL

- Creatinine < 130 mmol/l or creatinine clearance > 50 ml/min; measured or
calculated

- Urine dipstick for proteinuria < 2+. If urine dipstick is ≥ 2, 24 hour urine
must demonstrate < 500 mg of protein in 24 hours

- No pre-existing sensory neurotoxicity grade ≥ 1 (CTCAE)

- Patients of reproductive potential must agree to practice two effective medically
approved contraceptive method during the trial and 3 months afterwards

- Signed written informed consent.

Exclusion Criteria:

- Concurrent active malignancy other than localized, non-melanoma skin cancer or
carcinoma-in-situ of the cervix (unless definitive treatment was completed 5 years or
more before study entry and the patient has remained disease free)

- Anti-cancer therapy including chemotherapy, radiotherapy, endocrine therapy,
immunotherapy or use of other investigational agents within the 3 weeks prior to
start of therapy (or a longer period depending on the defined characteristics of the
agents used e.g. 6 weeks for mitomycin or nitrosourea). Patients may continue the use
of LHRH agonists for cancer; bisphosphonates for bone disease and corticosteroids.

- Patients, selected for sequential chemoradiotherapy, are excluded if no disease
control (all responses except progression) is obtained after induction chemotherapy.

- Prior:

- Ipsilateral radiotherapy to the chest;

- Chemotherapy for other indications than NSCLC within the last 5 years

- History of interstitial pneumonitis (to include diffuse alveolar damage,
non-malignant causes of pneumonitis, ARDS, alveolitis, cryptogenic organising
pneumonia, obliterative bronchiolitis, non-malignant causes of pulmonary fibrosis,
eligibility based on the judgement of the primary investigator), active infection on
day of enrolment

- Significant cardiovascular disease as defined by:

- History of congestive heart failure requiring therapy;

- History of unstable angina pectoris or myocardial infarction up to 6 months
prior to trial entry;

- Presence of severe valvular heart disease;

- Presence of a ventricular arrhythmia requiring treatment;

- Uncontrolled hypertension

- Any psychological, familial, sociological or geographical condition potentially
hampering compliance with the study protocol and follow-up schedule; those conditions
should be assessed with the patient before registration in the trial.

- Participation in other trial with investigational drug or treatment modality

- Co-existing serious active infection requiring parenteral antibiotics

- Patients with hepatic disease e.g. patients with known serologically positive
Hepatitis B or Hepatitis C as they may be more at risk of toxicity from Olaparib

- Immunocompromised patients e.g. human immunodeficiency virus (HIV)

- Myelodysplastic syndrome/acute myeloid leukaemia or features suggestive of MDS/AML on
peripheral blood smear.

- Any co-existing medical condition that in the investigator's judgement will
substantially increase the risk associated with the patient's participation in the
study

- Gastrointestinal disorders that may interfere with absorption of the study drug or
patients who are not able to take oral medication

- Concomitant medications:

- Any previous treatment with a PARP inhibitor, including Olaparib

- Patients receiving the following classes of inhibitors of CYP3A4 (see Section
7.4 for guidelines and wash out periods)

- Azole antifungals

- Macrolide antibiotics

- Protease inhibitors

- Persistent grade 2 or greater toxicities, from any cause

- Pregnant or breast-feeding women