PIK3CD and glioblastoma: Despite these negative results, an ongoing phase IIB clinical trial in patients with recurrent GBM is assessing the antitumor activity of Pembrolizumab (MK-3475, a PD-1 monoclonal antibody) alone or in combination with GDC-0941 or other PI3K inhibitors, including NVP-BEZ235 (NCT02430363).