POMB/ACE, a cocktail of 7 drugs to treat intermediate to poor prognosis and high volume germ cell cancers: A large retrospective study.

419 Background: Patients presenting with intermediate and poor risk germ cell tumours tend to be young and fit. Although more than half of patients may hope to be cured, a proportion will die because of their cancer. An aggressive strategy is required to maximise the chance of cure. Alternating high dose chemotherapy regimens have been trialled with varying outcomes. We present real world data demonstrating the efficacy and safety of first-line POMB/ACE (Cisplatin, Vincristine, Methotrexate, Bleomycin alternating with Actinomycin D, Cyclophosphamide, Etoposide) for these patients. Methods: 40 metastatic germ cell patients treated with POMB/ACE were identified at our centre. Patients were classified as being in intermediate or poor prognostic groups based on the International germ cell cancer collaborative group classification (IGCCCG). Treatment was administered every 2 weeks for up to 7 cycles. Response to treatment was determined by radiological imaging and serum tumour markers. Toxicities were evaluated using CTCAE version 5.0. Results: Clinical characteristics were as follows: median age at diagnosis 32 years (range 18-69). 36 patients (90%) were male and 4 patients (10%) were female. 29 (73%) presented with poor risk disease and 11 (27%) with intermediate risk. Patients completed between 1 and 7 cycles of POMB/ACE with the median number of cycles being 5. Data on toxicity severity was collected where available. This is summarised in the table. One grade 4 event was noted. 10 patients experienced grade 3 toxicities. Interestingly no patients were reported to develop bleomycin lung toxicity. This may be due to bleomycin being omitted in patients felt to be at higher risk of lung toxicity (smokers, older patients, pre-existing lung conditions). 30 (75%) patients were progression free following POMB/ACE. 9 (22%) patients went on to have subsequent systemic chemotherapy regimens and high dose stem cell transplant (HDSCT), as they had high volume disease, and persistent marker positive disease. 16 (40%) patients went on to have further surgical interventions, most commonly retroperitoneal lymph node dissection (RPLND), no active malignancy was seen in the resected specimen. At a median follow-up of 43 months, 39 (97.5%) of patients are still alive. Conclusions: POMB/ACE is a safe and effective regimen for patients presenting with intermediate to poor risk germ cell tumours. Patients with high volume disease should be considered for subsequent HDSCT to achieve better outcomes. [Table: see text]