Experiences with Caspofungin Plus Posaconazole in Immunocompromised Adults with Invasive Aspergillosis (IA) Refractory to Prior Standard Therapy.

Background: Aspergillosis is a lethal infection of immunocompromised patients that respond poorly to antifungal therapy. Caspofungin (CAS) or Posaconazole (POS) as salvage monotherapy for IA have response rates of 45% and 42% respectively. Preliminary results of in vitro studies, animal models and clinical studies suggest that combination therapy with azoles and echinocandins may have additive activity against Aspergillus species.

Methods: Seven adult patients after unrelated haematopoietic stem cell transplantation, with proven, probable or possible IA (per EORTC/MSG criteria) and refractory to standard antifungal therapy received Caspofungin plus Posaconazole (standard monotherapy dosage). All patients had > 3 days of combination antifungal therapy. Underlying diseases were AML (n=5), Biphenotypic leukaemia (n=1), Mantle cell Lymphoma (n=1). Three patients were neutropenic (ANC<500), all patients received immunosuppressive medication. IA sites were lung (n=6) and liver (n=1). All patients were evaluable for toxicity. Efficacy was assessed by signs, symptoms and CT-scan/ultrasound. Favourable responses (complete or partial) required significant clinical and radiographic/ultrasound improvement.

Results: Success at end of combination therapy (EOCT) was seen in six patients (86%). One critically ill patient died (due to bacterial sepsis and severe acute GvHD) four days after first administration of combination therapy. One patient with complete radiographic response died 20 days after EOCT due to bacterial sepsis in relapse of AML. Combination therapy at 4 to 59 (mean 35.7) days was well tolerated. No patient discontinued combination therapy due to toxicity. Follow up from start of combination therapy was 4 to 204 (mean 79.8) days.

Conclusion: Randomized trials are warranted to determine whether this combination should be used as primary therapy for aspergillosis.