Study of Efficacy and Safety of Buparlisib (BKM120) Plus Paclitaxel Versus Placebo Plus Paclitaxel in Recurrent or Metastatic Head and Neck Cancer Previously Pre-treated With a Platinum Therapy

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 12 unstained slides to be provided. Enrollment in the study is contingent on confirmation of an adequate amount of tumor 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);