Abstract 126P
Background
Metronomic cyclophosphamide (MC) is an oral regimen characterized by continuous administration of low doses of drug. MC showed efficacy and favorable safety profile in advanced and metastatic sarcomas, especially after standard treatments failure or in fragile patients.
Methods
We performed a retrospective analysis of patients (pts) with histological diagnosis of advanced or metastatic soft tissue and bone sarcomas in treatment with MC from 2021 to 2024 at Regina Elena National Cancer Institute in Rome, an EURACAN (European Reference Network on Rare Adult Cancers) sarcoma referral centre.
Results
A total of 33 pts treated with MC were analyzed (male/female: 18/15, median age: 68 years (yrs), range: 20-86 yrs). Histological subtypes included: 21.2% liposarcoma, 21.2% chondrosarcoma, 15.2% leiomyosarcoma, 12.1% myxofibrosarcoma, 9.1% undifferentiated pleomorphic sarcoma, 3% osteosarcoma, 18.2% others. At diagnosis, 21 pts presented with localized and 12 with advanced disease. Twenty-one pts received chemotherapy before MC, while 12 pts were treatment-naïve. In 23 pts, MC was initiated at the standard dose of 50 mg/die, while 5 pts received 50 mg 1 day on/1 day off and 5 pts received 50 mg d1-14 q28. During MC, 9 pts (27.3%) reported drug-related toxicities: G1 hematological toxicity (9.1%), G1 renal toxicity (15.2%), G3 renal toxicity (3%), G1 hepatic toxicity (6.1%), G1 gastrointestinal toxicity (3%). No dose reductions were required. In 2 pts, MC was interrupted and resumed after a median of 41 days (range: 7-75 days). Among 18 pts (54.5%) with evaluable responses, the best responses were as follows: 11 progressive disease, 6 stable disease, 1 partial response, with a disease control rate (DCR) of 38.9%. Nine pts (27.3%) continued MC beyond PD, with median duration of 8 months (mth). Median progression-free survival (PFS) from the start of MC treatment was 4 mth, 1 yearPFS: 11%. Median overall survival (OS) was 5 mth, 1yearOS:29%.
Conclusions
MC for treatment of sarcomas showed a good safety profile with modest benefit in term of survival and a DCR of 38.9%. This treatment is a promising strategy for advanced settings after standard treatment failure or in fragile patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.