Eligibility Criteria:
Inclusion Criteria:
* Age ≥ 12 years
* Karnofsky performance score of ≥ 60 (Eastern Cooperative Oncology Group (ECOG) performance score of 0, 1, or 2)
* Histologically confirmed diagnosis of classic HL (ie, nodular sclerosis, mixed cellularity, lymphocyte depleted, and or lymphocyte rich types)
* Nodal HL that shows fluorodeoxyglucose (FDG) avidity (defined as focal or diffuse FDG uptake above background in a location incompatible with normal anatomy or physiology), and is measurable (defined as the presence of ≥ 1 nodal lesion that measures ≥ 2 cm in a single dimension as assessed by CT, PET/CT, or magnetic resonance imaging (MRI))
* Relapsed or refractory HL after prior myeloablative therapy with autologous stem cell transplantation (ASCT) or after ≥ 2 prior chemotherapy-containing regimens and no curative option with conventional therapy
* Discontinuation of all radiotherapy or chemotherapy for the treatment of HL greater than or equal to 3 weeks before initiation of study treatment and discontinuation of all radioimmunotherapy for HL (Visit 2)
* All acute toxic effects (excluding alopecia, neurotoxicity, or anemia) of any prior antitumor therapy resolved to Grade ≤ 2 before initiation of study treatment (Visit 2)
* For men and women of childbearing potential willingness to abstain from sexual intercourse or employ an effective method of contraception during the study drug administration and follow-up periods
* Willingness and ability to provide written informed consent and to comply with protocol requirements
Exclusion Criteria:
* Known active central nervous system or leptomeningeal lymphoma
* History of a non-lymphoma malignancy except for the following: adequately treated local basal cell or squamous cell carcinoma of the skin, cervical carcinoma in situ, superficial bladder cancer, localized prostate cancer, other adequately treated Stage 1 or 2 cancer currently in complete remission, or any other cancer that has been in complete remission for ≥ 5 years
* Evidence of ongoing systemic bacterial, fungal, or viral infection (excluding viral upper respiratory tract infections) at the time of initiation of study treatment (Visit 2)
* Pregnancy or breastfeeding
* Ongoing alcohol or drug addiction
* Known history of drug-induced liver injury, chronic active hepatitis C virus (HCV), chronic active hepatitis B virus (HBV), alcoholic liver disease, non-alcoholic steatohepatitis, primary biliary cirrhosis, ongoing extrahepatic obstruction caused by stones, cirrhosis of the liver or portal hypertension
* History of prior allogeneic bone marrow progenitor cell or solid organ transplantation
* Ongoing immunosuppressive therapy, including systemic corticosteroids.
* Prior therapy with idelalisib
* Exposure to another investigational drug within 3 weeks prior to start of study treatment
* Concurrent participation in another therapeutic treatment trial
* Prior or ongoing clinically significant illness, medical condition, surgical history, physical finding, ECG finding, or laboratory abnormality that, in the investigator's opinion, could affect the safety of the patient; alter the absorption, distribution, metabolism or excretion of the study drug; or impair the assessment of study results
* Prior therapy with any drug that inhibits Akt, Bruton tyrosine kinase (BTK), Janus kinase (JAK), mammalian target of rapamycin (mTOR), phosphatidylinositol 3 kinase (PI3K) (including idelalisib), or spleen tyrosine kinase (SYK)