Caspofungin as first line therapy of pulmonary invasive fungal infections in 32 immunocompromised patients with hematologic malignancies

Invasive Fungal Infections (IFI) remain a severe and major complication among patients with hematologic diseases, but the recent availability of new antifungal agents (echinocandins and new azoles) have improved the chance of cure. Caspofungin (Cancidas-Merck) is a large lipopeptide molecule able to inhibit the enzyme complex 1,3-D-glucan synthetase; this action specifically damages the fungal cell wall. Caspofungin (CAS) is active, in vitro and in vivo, against most Candida species and Aspergillus species. We report on our experience with this drug as first-line therapy for proven or probable pulmonary IFI in immunocompromised patients with hematologic malignancies. Thirty-two consecutive patients (20 males and 12 females, with a median age of 52 yr) have been treated with CAS (27 acute leukemias, 1 chronic leukemia, 3 lymphomas and 1 multiple myeloma). Sixteen patients (50%) had a relapsed or resistant hematologic disease, while 12 patients were in complete remission and 4 were at onset of disease; 8/32 (25%) developed IFI after a hematopoietic stem cell transplant (HSCT) procedure. Seven out of 32 patients (22%) had a proven pulmonary IFI (7/7 Aspergillosis) and 25 (78%) had a probable IFI with pulmonary localization as defined according to international consensus. Thirty-one patients (97%) had less than 1000 granulocytes/mL at onset of infection and at the start of CAS therapy. The CAS was given at the dose of 70 mg on day 1, followed by 50 mg/day. Median duration of CAS therapy was 20 d (range 8-64); all the 31 neutropenic patients received concomitant granulocyte colony-stimulating factor (G-CSF). The overall response rate was 56% (18/32) with 12/18 complete responses and 6/18 partial responses; two patients (6%) had a stable disease. Twelve out of 32 (38%) did not respond and seven died of mycotic infection. Univariate analysis showed that granulocytes recovery (> 500/mL vs. < 500/mL) and status of hematologic disease (remission/onset vs. refractory/relapsed) were significantly associated to favourable outcome. No clinical adverse events (AE) were reported and only a grades I and II transient increase of serum alkaline phosphatase and/or transaminases occurred in 4/32 (12%) patients. After CAS therapy six non-responders and six cases with a partial or stable response were rescued with voriconazole. Two out of six patients (33%) in the former group and 6/6 (100%) in the latter obtained a complete resolution of IFI. Our experience suggests an efficacy of CAS, in combination with G-CSF, as first-line treatment of proven or probable IFI with pulmonary localization. The drug was well tolerated and there were no significant hepatic AE even in patients receiving CAS with cyclosporine after a HSCT. A significant proportion of non-responders or partial responders to CAS can be rescued with a subsequent voriconazole-based therapy.