Palliative ambulatory 14-day infusional ifosfamide in the outpatient setting for treatment of advanced soft tissue sarcomas (STS): “Old wine in a new bottle.”

Abstract

10039 Background: Ifosfamide (IFO) has recognised activity in soft tissue sarcomas. There is evidence for improved cytotoxicity and tolerability utilising a prolonged 14 day infusional outpatient regimen compared with the standard 3-day regimen (Loeffler et al 1990). We undertook a retrospective review of all patients treated with this regimen from September 2008 - December 2011 to determine toxicity and treatment response. Methods: Pts. were identified from our database and demographics, histological subtype, toxicity and survival outcomes were collected. IFO was given via central venous access using 2 x 7 day pumps at 1g/m2/day with mesna for 14 days q 4 weekly. Oral sodium bicarbonate was used to maintain alkaline urine with oral mesna for haematuria, and thiamine for symptoms of encephalopathy as required. Results: 29 patients (pts), with advanced sarcoma, median age 56 years (27-76 yrs), 14F 15 M, median number of cycles = 1 ( 1-9). At baseline: PS 0=1, 1=24, 2=4. 18 pts had de-differentiated liposarcoma (D-LPS), 6 synovial sarcoma, 5 had other subtypes. 12 pts received only 1 cycle, with 5 stopping due to encephalopathy. Ten patients developed encephalopathy, 9 occurring in cycle 1, other toxicity was tolerable, with Gr 2-3 nausea (15 pts) and vomiting (9pts) and only 2 Gr 3 episodes of myelotoxicity for all cycles. 4 patients achieved PR, (2 with D-LPS and 2 with Synovial sarcoma) 11 pts. had SD. Median PFS was 19 months and OS was 12.5 months. 2 pts. with D-LPS had a sustained prolonged response of 15 and 16 months. Conclusions: Infusional IFO is generally well tolerated; however a significant incidence of neurotoxicity was seen. Pts. with D-LPS demonstrated best response to treatment, a sarcoma subtype that has previously failed to respond to systemic therapy. This regime warrants further investigation.