Inclusion Criteria:

- Patient has histologically/cytologically-confirmed HNSCC.

- Patient has archival or fresh tumor tissue for the analysis of PI3K-related
biomarkers. One tumor block (preferred) or a minimum of 15 unstained slides to be
provided. Enrollment in the study is contingent on the central laboratory confirming
receipt of an adequate amount of tissue.

- Patients with recurrent or metastatic disease resistant to platinum-based
chemotherapy (defined as progression while on platinum-based chemotherapy given in
the recurrent/metastatic setting). Pretreatment with cetuximab is allowed

- Measurable disease as determined by per RECIST criteria v1.1. If the only site of
measurable disease is a previously irradiated lesion, documented progression of
disease and a 4 week period since radiotherapy completion is required

- Adequate bone marrow function and organ function

- ECOG Performance Status ≤ 1

Exclusion Criteria:

- Patient has received previous treatment with any AKT, mTOR inhibitors or PI3K pathway
inhibitors;

- Patient treated with more than one prior chemotherapy regimen for
recurrent/metastatic disease

- Patient has symptomatic CNS metastases. Patients with asymptomatic CNS metastases may
participate in this trial. The patient must have completed any prior local treatment
for CNS metastases ≥ 28 days prior to the start of study treatment (including
radiotherapy and/or surgery) and must have stable low dose of corticosteroid therapy;

- Patient has not recovered to ≤ grade 1 (except alopecia) from related side effects of
any prior antineoplastic therapy

- Patient has any of the following cardiac abnormalities:symptomatic congestive heart
failure, history of documented congestive heart failure (New York Heart Association
functional classification III-IV), documented cardiomyopathy, Left Ventricular
Ejection Fraction (LVEF) <50% as determined by Multiple Gated acquisition (MUGA) scan
or echocardiogram (ECHO); myocardial infarction ≤ 6 months prior to enrolment,
unstable angina pectoris, serious uncontrolled cardiac arrhythmia, symptomatic
pericarditis, QTcF > 480 msec on the screening ECG (using the QTcF formula);