Safety and Activity of SNX-5422 Plus Ibrutinib in CLL

Inclusion Criteria: * Males or non-pregnant, non-breastfeeding females 18 years-of-age or older * A diagnosis of CLL as defined by IWCLL 2008 criteria and currently on treatment with ibrutinib without evidence of disease progression. * No more than 4 prior lines of anti leukemia therapy (not including ibrutinib) * Presence of mutated BTK in ≥ 4% of peripheral blood or bone marrow CLL cells, or ≥1% and rising on two separate measurements obtained at least 28 days apart. * Life expectancy of at least 9 months * Karnofsky performance score 70 * Adequate baseline laboratory assessments * Signed informed consent form * Recovered from toxicities of previous anticancer therapy to CTCAE Grade ≤ 1 with the exception of alopecia * Subjects with reproductive capability must agree to practice adequate contraception methods. Exclusion Criteria: * Subjects experiencing toxicity with ibrutinib * Prior treatment with any Hsp90 inhibitor. * Major surgery or significant traumatic injury within 4 weeks of starting study treatment. * Conventional chemotherapy or radiation within 4 weeks. * The need for treatment with medications with clinically-relevant metabolism by the cytochrome P450 (CYP) 3A4 isoenzyme within 3 hours before or after administration of SNX-5422 * Screening ECG QTc interval 470 msec for females, 450 msec for males. * At increased risk for developing prolonged QT interval unless corrected to within normal limits prior to first dose of SNX-5422 * Patients with chronic diarrhea or with Grade 2 or greater diarrhea despite appropriate medical management. * Gastrointestinal diseases or conditions that could affect drug absorption * Gastrointestinal diseases that could alter the assessment of safety, including irritable bowel syndrome, ulcerative colitis, Crohn's disease, or hemorrhagic coloproctitis. * History of documented adrenal dysfunction not due to malignancy. * History of chronic liver disease. * Active hepatitis A or B. * Current alcohol dependence or drug abuse. * Use of an investigational treatment (except for ibrutinib) from 30 days prior to the first dose * Glaucoma, retinitis pigmentosa, macular degeneration, or any retinal changes detected by ophthalmological examination that are considered clinically important by examiner. * Psychological or social reasons that would hinder or prevent compliance with the requirements of the protocol or compromise the informed consent process.