Super-bioavailability-itraconazole (SUBA-itraconazole; Tolsura®) was developed to enhance dissolution and absorption of the active drug by utilizing a pH-dependent polymer matrix. This novel formulation confers more stable bioavailability for patients with elevated gastric pH, consumption of food or acidic substances, or other patient specific factors. Several studies have been conducted investigating its efficacy, as summarized in the below tables. In comparison, conventional itraconazole allows for 55% bioavailability, while the SUBA formulation is noted to be higher during chronic use. Bioavailability with food of conventional formulation is highly variable, whereas the SUBA formulation experiences a 27% reduction in bioavailability. Additionally, intersubject variability is noted to be 21% decreased with the SUBA formulation, as well as 22% increase in total plasma levels when co-administered with omeprazole. Studies have corroborated improved bioavailability, with one trial finding significantly higher mean trough levels accompanied by much less inter-patient variation (60% with conventional vs. 35% with SUBA). However, generalizability of results may be limited by disease states in which SUBA-itraconazole has been studied thus far. [1], [2]
A 2021 open-label trial (N= 89 participants) compared SUBA-itraconazole (n=43) to conventional itraconazole (n= 46) for the treatment of confirmed or suspected endemic mycoses. Patients were randomized to receive either SUBA-itraconazole 130 mg orally twice daily or conventional itraconazole 200 mg orally twice daily for up to 6 months, with regular follow-up to evaluate quality of life, overall drug tolerance, adverse events, and symptoms, as well as to collect pharmacokinetic samples. Pharmacokinetic serum levels of itraconazole and hydroxyl-itraconazole levels, including the combination itraconazole/hydroxyl-itraconazole levels, were not significantly different between trial arms. Additionally, the area under the curve (AUC) for hydroxyl-itraconazole and itraconazole was comparable in both arms. Reported adverse effects were similar between groups, with an overall rate of 74% and 85% of SUBA-itraconazole and conventional itraconazole patients, respectively, experiencing any adverse event; drug-related adverse effects affected 35% and 41% of patients, respectively. Cardiovascular effects (edema and hypertension), nausea, and appetite loss were most frequently reported. The authors concluded that although SUBA-itraconazole is dosed at about 60% of the usual conventional itraconazole dosage (130 mg orally twice daily vs. 200 mg orally twice daily), it exhibits nearly identical blood levels to conventional itraconazole. SUBA-itraconazole and conventional itraconazole demonstrated a similar safety profile, although SUBA-itraconazole is marginally more well tolerated. Of note, this information is derived from the study abstract, as the full trial does not appear to have been published. [3]
A randomized, multicenter, open-label, crossover, bioequivalence study was conducted to assess the pharmacokinetics, safety, efficacy, tolerability, and health economics of oral SUBA-itraconazole compared to conventional itraconazole in patients with proven or probable invasive endemic fungal infection. Patients were administered either SUBA-itraconazole (n= 42) or conventional itraconazole (n= 46) over two stages: an initial 42-day period, followed by continued treatment until Day 180. For SUBA-itraconazole, patients received two 65 mg capsules TID with food for the first three days, then two capsules BID for the remainder of the study. Patients in the conventional itraconazole group received two 100 mg capsules TID with food for the first three days, followed by two capsules BID for the remainder of the study. Findings revealed that a lower percentage of patients achieved therapeutic itraconazole and hydroxy-itraconazole levels with SUBA-itraconazole (60.5%) compared to conventional itraconazole (71%) on Day 14, but this difference was not statistically significant. However, a higher percentage of patients maintained therapeutic plasma trough levels on Day 42 with SUBA-itraconazole (69.3% vs. 58%; p= 0.80). Notably, treatment-related adverse events (15 patients vs. 27 patients) and serious adverse events (4 patients vs. 12 patients) were less frequent with SUBA-itraconazole. One patient receiving SUBA-itraconazole died during the study period, while no deaths occurred in the conventional itraconazole group. [4], [5]