Clinically significant ascites, defined as ascites that is symptomatic or has resulted in a paracentesis in the past 3 months Uncontrolled ascites requiring weekly large-volume paracentesis for 2 consecutive weeks prior to initiation of study treatment Patients who had therapeutic paracentesis of ascites (> 1L) within the 3 months prior to starting study treatment or who, in the opinion of the investigator, will likely need therapeutic paracentesis of ascites (> 1L) within 3 months of starting study treatment. Refractory encephalopathy or ascites Fluctuating ascites Ascites that your doctor will manage by increasing your medications or by performing non-invasive methods (eg, paracentesis) to control, within 6 months prior to the first scheduled dose. Clinical evidence of ascites (trace ascites on imaging acceptable) No evidence of clinically apparent ascites or active encephalopathy, and/or varices that have not been treated; subjects with controlled ascites or encephalopathy are eligible so long as they meet Childs-Pugh score criterion; please note that controlled ascites and encephalopathy require scores of 2 each when calculating the C-P score Clinical ascites or metastatic pleural fluid Ascites refractory to medical therapy (mild to moderate ascites is allowed) No clinical evident ascites that required therapeutic paracentesis Malignant ascites that is clinically detectable by physical examination or is symptomatic; evidence of radiographic ascites that is not clinically significant will not be an exclusion criterion Clinically apparent ascites on physical examination, ascites present on imaging studies is allowed Presence of symptomatic liver failure including ascites and hepatic encephalopathy Requirement for diuretics, paracentesis, or other medications or procedures to control ascites or hepatic encephalopathy within 6 months before enrollment\r\n* Diuretics or medications such as lactulose used for other indications (e.g. edema, constipation) are allowed Decompensated liver disease as evidenced by clinically significant ascites refractory to diuretic therapy, hepatic encephalopathy, or coagulopathy Moderate or severe ascites Has clinically relevant ascites at baseline (defined as requiring paracentesis) or with moderate radiographic ascites; a minimal amount of radiographic ascites is allowed Participants with uncontrolled gross ascites or encephalopathy; assessment of ascites will be determined by the treating physician Patients with any clinically apparent ascites or who have undergone a paracentesis within 7 days of enrollment Evidence of severe portal hypertension with evidence of decompensation either with bleeding varices, large volume ascites, or hepatic encephalopathy If present, clinically significant or symptomatic amounts of ascites should be drained prior to Day 1. Clinical ascites Patients with malignant small bowel obstruction within the last 6 months, on parenteral nutrition, clinically significant ascites (palpable on physical exam and/or causing symptoms) or ascites requiring fluid removal more than twice in the last 6 weeks Subjects with clinically apparent ascites or encephalopathy, or untreated varices are not eligible for enrollment Moderate to large volume ascites. Significant ascites that require therapeutic paracentesis At risk for hepatic or renal failure\r\n* Serum creatinine > 1.5 mg/dl\r\n* Serum bilirubin > 1.3 mg/ml\r\n* Albumin < 2.0 g/dL\r\n* Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 5 times upper normal limit\r\n* Any history of hepatic encephalopathy\r\n* Cirrhosis or portal hypertension\r\n* Clinically evident ascites (trace ascites on imaging is acceptable) Presence of ascites (as determined by clinician) Ascites refractory to medical therapy Ascites refractory to medical therapy Any evidence of ascites (beyond trace) No clinical evidence of hepatic failure (e.g. coagulopathy, ascites) Patients with current cirrhotic status of Child-Pugh class A only (5-6 points with total bilirubin < 2 mg/dL for dose-escalation) with no encephalopathy and no clinical ascites (ascites controlled by diuretics is also excluded in this study). Evidence of significant ascites as determined by the investigator Hepatic blood flow abnormalities and/or large-volume ascites Presence of ascites that is not medically controlled or that required a therapeutic paracentesis within the last 3 months prior to initiation of study therapy Patients must be willing and able to undergo ascites fluid collection pre- and post-study treatment if adequate ascites is present; patients without adequate ascites may also participate in the trial Has clinically apparent ascites on physical examination. Note: ascites detectable on imaging studies only ARE allowed. Moderate or severe ascites. Clinically evident ascites (trace ascites on imaging is acceptable) Any prior (within 1 year) or current clinically significant ascites as measured by physical examination and that requires paracentesis for control; Clinically significant ascites Decompensated liver disease as evidenced by clinically significant ascites refractory to diuretic therapy, hepatic encephalopathy, or coagulopathy Have greater than grade 2 ascites at time of enrollment. Have presence of clinically relevant ascites. Any prior or current clinically significant ascites Significant or symptomatic amount of ascites should be drained prior to first dose of BBI608. Clinically evident ascites (trace ascites on imaging is acceptable) Has clinically apparent ascites on physical examination No clinical ascites (mild ascites on scans permissible) Ascites requiring intervention Subject has uncontrolled symptomatic ascites. Uncontrolled or clinically relevant ascites Histologically confirmed metastatic ovarian or GI malignancy with malignant ascites amenable for paracentesis; adjudication of malignant ascites can be made on clinical grounds e.g. in the absence of cirrhosis or other non-malignant causes of ascites Presence of clinically significant ascites Decompensated liver disease as evidenced by clinically significant ascites refractory to diuretic therapy, hepatic encephalopathy, or coagulopathy Moderate or severe ascites No moderate-to-severe ascites (subjects with ascites restricted to the perihepatic space or pelvic cavity) Clinical ascites Clinically evident ascites (trace ascites on imaging is acceptable) Uncontrolled ascites defined as not easily controlled by stable doses of diuretics Uncontrolled ascites (defined as not easily controlled with diuretic or paracentesis treatment). Ascites detected by CT, ultrasound (US) or MRI; (trace ascites will not be an exclusion) Presence of symptomatic liver failure including ascites and hepatic encephalopathy Patients cannot have active ascites Subjects with refractory ascites, defined as ascites needing drainage catheter or therapeutic paracentesis more often than every 4 weeks Recurrent symptomatic malignant ascites having required at least 2 paracenteses within a 45-day interval prior to baseline paracentesis Compensated cirrhosis defined as a Child-Pugh score of 5 or 6 at Screening • A minimal rim of ascites if detected at imaging is acceptable. Exclude ascites that requires the need to apply diuretic treatment to control ascites Significant or symptomatic amounts of ascites should be drained prior to Cycle 1 Day Clinically significant ascites or clinical evidence or history of portosystemic hypertension or cirrhosis. No signs of decompensated liver cirrhosis or ascites requiring therapeutic paracentesis Uncontrolled ascites requiring weekly large volume paracentesis for 3 consecutive weeks prior to enrollment Poorly controlled ascites and/or requirement for therapeutic paracentesis more frequently than once every 3 months. Clinically significant ascites Unwilling to allow removal of tumor biological samples for analysis, i.e., biopsies of tumor lesions, and/or collection of ascites fluid from abdominal ascites (if present) Presence of ascites that requires paracentesis more frequently than once every 21 days. Presence of ascites that preclude biopsy of liver lesions. Subjects with sensory neuropathy, ascites, or plastic biliary stent. Subjects with clinically significant ascites Clinically evident ascites Active infection, ascites, hepatic encephalopathy Evidence of ascites on imaging study, or the use of diuretics for ascites Patients with clinically significant ascites requiring paracentesis on 2 or more occasions within 4 weeks prior to start of study treatment Significant peri-hepatic ascites interfering with safe/effective PTBD. Patients presenting with ascites Presence of ascites Moderate or severe ascites History of or current hepatic encephalopathy or clinically meaningful ascites. Ascites absent Uncontrolled large ascites Clinically or radiographically detectable ascites (beyond trace/rim of ascites) or ascites requiring medication Minimal or non-symptomatic ascites Ascites or other clinical or radiographical signs of portal hypertension Uncontrolled ascites that is not stable with medical management (i.e., on diuretics and salt restriction) as defined by requiring therapeutic paracentesis more than once every 4 weeks. Uncontrolled ascites requiring weekly large volume paracentesis for 3 consecutive weeks prior to enrollment