Safety, Pharmacodynamics, Pharmacokinetics, and Efficacy of GS-9901 in Adults With Relapsed or Refractory Follicular Lymphoma, Marginal Zone Lymphoma, Chronic Lymphocytic Leukemia, or Small Lymphocytic Lymphoma

Inclusion Criteria:

* Diagnosis of FL, MZL, SLL, or CLL (meeting International Workshop on CLL \[IWCLL\] Criteria, 2008) as documented by medical records and with histology based on criteria established by the World Health Organization

  * FL Grades 1, 2, or 3a
  * SLL with absolute lymphocyte count of \< 5 x 10\^9/L at initial diagnosis
  * MZL (splenic, nodal, or extra-nodal)
* Prior treatment for FL or CLL/SLL with ≥ 1 prior chemotherapy-based or immunotherapy-based regimen with no approved therapies available
* Presence of radiographically measurable lymphadenopathy or extra nodal lymphoid malignancy
* All acute toxic effects of any prior antitumor therapy resolved to Grade ≤1 before the start of study therapy (with the exception of alopecia \[Grade 1 or 2 permitted\], or bone marrow parameters \[any of Grade 1, 2, or 3 permitted)
* Eastern Cooperative Oncology Group (ECOG) ≤ 2
* Able to provide written informed consent

Exclusion Criteria:

* History of lymphoid malignancy other than FL, MZL, SLL, or CLL
* History of myelodysplastic syndrome
* History of a non-lymphoid malignancy except for the following: adequately treated local basal cell or squamous cell carcinoma of the skin, cervical carcinoma in situ, superficial bladder cancer, asymptomatic prostate cancer without known metastatic disease and with no requirement for therapy or requiring only hormonal therapy and with normal prostate-specific antigen for ≥ 1 year prior to start of study therapy, or any other cancer that has been in complete remission for ≥ 5 years
* Evidence of ongoing systemic bacterial, fungal, or viral infection at the time of start of study therapy
* Ongoing drug-induced pneumonitis
* Ongoing inflammatory bowel disease
* History of prior allogeneic bone marrow progenitor cell or solid organ transplantation
* History of prior therapy with any inhibitor of serine/threonine kinase (AKT), Bruton tyrosine kinase (BTK), Janus kinase (JAK), mammalian target of rapamycin (mTOR), phosphatidylinositol 3-kinase (PI3K), or spleen tyrosine kinase (SYK)
* Ongoing immunosuppressive therapy, including systemic corticosteroids for treatment of lymphoid malignancy