Steady-state plasma concentrations of phenylacetate and phenylacetylglutamine were measured during antineoplaston treatment in this study (refer to Table 1). High serum concentrations of phenylacetate were associated with central nervous system toxic effects. Treatment-related neurologic toxicity included excessive somnolence, somnolence plus confusion, and increased frequency of underlying focal motor seizures. MRI scans also revealed increased cerebral edema in two patients. One of the nine patients had findings suggestive of a diffuse metabolic encephalopathic process; this patient and one other had antineoplaston treatment interrupted and received dexamethasone for their symptoms, which resolved within 48 hours. These patients resumed their treatment with a 25% decrease in dose and had no recurrence of neurologic toxicity. Another patient manifested persistent confusion that stopped after discontinuation of antineoplastons. Other toxicities included nausea and vomiting, headache, myalgia, and edema. These effects were reported as usually mild to moderate, except for headache, which was severe in two patients. The patient who experienced persistent confusion also developed severe cutaneous erythema, pruritus, and facial edema, at which time treatment was permanently discontinued. Another patient had treatment discontinued because of edema of the extremities and face that was unresponsive to diuretics. The edema resolved after discontinuation of antineoplastons.
A phase II study also conducted by the developer and his associates at his clinic reported on 12 patients with recurrent and diffuse intrinsic brain stem glioma. Of the ten patients who were evaluable, two achieved complete tumor response, three had partial tumor response, three had stable disease, and two had progressive disease. Patients ranged in age from 4 to 29 years. Treatment with escalating intravenous bolus injections of antineoplastons A10 and AS2-1 continued for 6 months. The average dose of A10 was 11.3 g/kg daily, and the average dose of AS2-1 was 0.4 g/kg daily. Adverse effects included skin allergy, anemia, fever and hypernatremia, agranulocytosis, hypocalcemia, hypoglycemia, numbness, tiredness, myalgia, and vomiting.
A similar study of 12 pediatric patients with recurrent and progressive brain tumors was conducted by the developer and his associates at his clinic. Six patients were diagnosed with pilocytic astrocytoma, four had low-grade glioma, one had grade 2 astrocytoma, and one had visual pathway glioma. Both A10 and AS2-1 were administered intravenously and later orally, for an average duration of 16 months. The average dose of A10 was 7.95 g/kg daily, and the average dose of AS2-1 was 0.33 g/kg daily. Injections were discontinued after the patients showed stable disease or partial or complete tumor response. The patients then received oral administration of A10 and AS2-1 for an average duration of 19 months. Average doses for both A10 and AS2-1 were 0.28 g/kg daily. Of the 12 patients, one was nonevaluable, three were still in the study at the time of publication, and two achieved complete response. The remaining six patients requested removal from the study.