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 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 HCV, chronic active 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 GS-1101 (CAL-101).

- 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 GS 1101), or spleen tyrosine kinase (SYK).