Inclusion Criteria:

- Female ≥ 18 years

- ECOG ≤ 2

- Histologically confirmed endometrial cancer

- Not eligible for exclusive curative treatment by surgery and/or radiotherapy

- Initial metastatic endometrial cancer not treated with chemotherapy or radiotherapy
prior to inclusion OR

- Recurrent endometrial cancer previously treated with adjuvant CT and RT, presenting
with a disease-free interval of at least 12 months

- Presence of one or more measurable lesion(s) outside the irradiated areas

- Availability at inclusion of samples of tumor tissue (a block or at least 20
unstained slides) for tumor sub-classification and for routine molecular analysis

- Satisfactory biological functions: PNN ≥ 1.5 x 109/L, platelets ≥ 100 x 109/L,
hemoglobin ≥ 9.0 g/dL, INR ≤ 2, standard normal values for potassium, calcium and
magnesium, serum creatinine ≤ 1.5 x ULN or creatinine clearance > 50 mL/min, ALT and
AST within normal range (or ≤ 3.0 x ULN if liver metastases present), Alkaline
phosphatase ≤ 2.5 x ULN, serum bilirubin within normal range (or ≤ 1.5 x ULN if liver
metastases present; or total bilirubin ≤ 3.0 x ULN with direct bilirubin within
normal range in patients with well documented Gilbert Syndrome), fasting glycemia ≤
120 mg/dL or ≤ 6.7 mmol/L

- Life expectancy 3 months

- Post menopausal woman with at least 12 months of natural (spontaneous) amenorrhea

- Negative serum pregnancy test ≤ 72 hours prior to initiating treatment for woman of
child-bearing potential

- Consent form signed before any procedure performed

Exclusion Criteria:

- Previous treatment with PI3K inhibitors and/or mTOR

- Presence of symptomatic CNS metastases. Patient must have completed any prior
treatment for CNS metastases ≥ 28 days and, if on corticosteroid therapy, should be
receiving a stable low dose

- Concomitant presence or history of another malignant tumor in the past 3 years prior
to inclusion (except spinocellular or cutaneous basal cell epithelioma or
non-melanomatous skin cancer treated successfully)

- Suffering from mood disorders based on an evaluation by the investigator or a
psychiatrist OR with a given score according to the PHQ-9 or GAD-7 mood evaluation
scale (cf protocol)

- Concomitant administration of another approved or investigational anticancer agent

- Pelvic and/or para-aortic radiotherapy within ≤ 28 days prior to inclusion or
persistent side effects from this treatment on implementation of the selection
procedures

- Major surgery during the 28 days prior to starting investigational drug or persistent
side effects from surgery

- Uncontrolled diabetes (HbA1c > 8 %)

- Presence of an active heart disease, especially: LVEF < 50 % determined by MUGA or
ECHO, QTc > 480 msec on ECG recorded during selection (with QTcF formula), angina
warranting the administration of anti-angina treatment, ventricular arrhythmia except
for benign premature ventricular contractions, supraventricular and nodal arrhythmias
warranting a pacemaker or not controlled by a treatment, conduction anomalies
warranting a pacemaker, valvular disease with documented involvement of cardiac
function, symptomatic pericarditis

- History of heart disease

- Currently receiving treatment to prolong QT interval accompanied by a known risk of
triggering wave burst arrhythmia. Impossible to stop treatment or to replace it
before starting study medication

- GI dysfunction or disease that could significantly interfere with absorption of
BKM120

- Chronic treatment with corticosteroids or other immunosuppressants

- Any other severe and/or uncontrolled concomitant disease, which is likely to
contraindicate the patient's participation

- Known treatment non-compliance

- Currently receiving treatment known to be inhibitors or moderate and strong inducers
of isoenzyme CYP3A. Impossible to stop this treatment or to replace it with a
different treatment before starting the study product

- Severe pneumonitis

- Grade ≥ 3 biological anomalies

- Known history of HIV infection

- Pregnant woman or nursing mother