Posaconazole is effective in preventing invasive fungal infections in patients undergoing chemotherapy for acute leukemia. The goal of the study was to determine the incidence of invasive aspergillosis in a center before and after the implementation of a protocol for posaconazole prophylaxis and to evaluate its real-life adherence.
We reviewed the medical charts of all adult patients admitted to the hematology ward for acute leukemia between October 2011 and September 2014. During the first 18 months, anti-aspergillus preemptive therapy was used, while patients received posaconazole prophylaxis in the second 18-month period. The primary endpoint was the incidence of invasive aspergillosis. In addition, we assessed the various difficulties linked to the application of the protocol.
We retrieved records for 65 patients with acute leukemia for a total of 106 courses of remission-induction chemotherapy. The incidence of proven or probable invasive aspergillosis reported was 9.7% (3 patients) in the preemptive group and 4.3% (1 patient) in the prophylaxis group. The 5.4% decrease in incidence is however not statistically significant. When including possible invasive aspergillosis, the incidence decreased from 16.1% (5 patients) without prophylaxis to 8.7% (2 patients) with posaconazole. The number needed to treat varied from 14 to 19.
Before and during the implementation of the prophylaxis protocol, many strategies were used to inform doctors and medical staff. During the preemptive therapy period, physicians adhered to the protocol in only 82% of treatments, as compared to 93.2% during the prophylaxis protocol (posaconazole prescription was omitted in 2.3% and delayed in 4.5%). Of note, posaconazole prophylaxis was interrupted in 2.3% (1 patient) due to intolerance.
We found a reduction of the incidence of invasive aspergillosis in our center with the implementation of the new protocol. Despite adequate physician adherence to the protocol, there were still cases of infections. This may be possibly explained by a lower bioavailability of the oral-suspension posaconazole or more resistant strains. A third phase of this study could focus on the introduction of posaconazole delayed-release tablet.