Purpose: A previous study noted frequent B-RAF mutations among European patients with cisplatinresistant but not cisplatin-sensitive germ cell tumors (GCT). We sought to validate this finding by assessing for these mutations among patients with GCT at our center.Experimental Design: Adolescent and adult patients with GCT who received cisplatin-based chemotherapy and had tumor tissue available were eligible for participation. Response to cisplatin was reviewed to determine sensitivity and resistance. Tumor DNA was extracted and subjected to Sequenom analysis to detect hotspot alterations in FGFR3, AKT1, PIK3CA, KRAS, HRAS, NRAS, and BRAF with Sanger sequencing for confirmation. Nine GCT cell lines with varying degrees of cisplatin sensitivity and resistance were also assayed by Sequenom.Results: Seventy (24 cisplatin-sensitive; 46 cisplatin-resistant) of 75 patients had tumors with sufficient quality DNA to perform Sequenom. Nineteen mutations were detected among 16 (23%) patients but no BRAF mutations were identified. Similarly, none of the cell lines harbored BRAF mutations. FGFR3 was the most frequent mutation, identified in 13% of both sensitive and resistant samples. All other mutations were exclusive to resistant cases (3 KRAS, 3 AKT1, 3 PIK3CA, and 1 HRAS).Conclusions: BRAF mutations are rare in American patients with GCT, including those with cisplatin resistance. However, other potentially targetable mutations occur in more than 25% of cisplatin-resistant patients. FGFR3, AKT1, and PIK3CA mutations are all reported for the first time in GCT. Whereas FGFR3 mutations occurred with equal frequency in both sensitive and resistant GCTs, mutations in AKT1 and PIK3CA were observed exclusively in cisplatin-resistant tumors.

Purpose Salvage high-dose chemotherapy with autologous stem cell transplant (ASCT), consisting of 2–3 sequential cycles of high-dose (HD) carboplatin and etoposide (CE) can achieve durable remissions in approximately one-half of relapsed germ cell tumor patients. To improve upon these results and based on success with paclitaxel, ifosfamide, and cisplatin (TIP) as salvage conventional-dose chemotherapy, we conducted a phase I/II trial of HD paclitaxel plus ifosfamide (TI), substituting carboplatin for cisplatin to allow dose escalation. Patients and Methods Treatment consisted of 1–2 cycles of TI and granulocyte colony stimulating factor for stem cell mobilization followed by three cycles of HD TI plus carboplatin (TIC) with ASCT every 21–28 days. Twenty-six patients were enrolled. For phase I, a standard 3+3 dose-escalation design was used. Results With no dose-limiting toxicities observed, the maximum tolerated dose (MTD) was not reached and the highest prespecified dose level (paclitaxel 250 mg/m2, ifosfamide 9990 mg/m2, carboplatin area under the curve = 24) was considered the MTD. Phase II employed a Simon two-stage design to estimate the complete response (CR) rate at the MTD. With 7/11 phase II patients achieving CR, efficacy was demonstrated. However, three patients developed delayed chronic kidney disease, resulting in premature trial closure. Conclusion TI-TIC was active in relapsed GCT but emergent chronic renal impairment, possibly from overlapping ifosfamide and carboplatin, preclude its further use. TI-CE, consisting of two cycles of TI plus three cycles of HD CE remains the standard-of-care HD chemotherapy regimen at Memorial Sloan Kettering Cancer Center.

26 patients were treated with 27 SCTs at two centres between 1999 and 2013. All patients had onset of symptoms before 7 years of age and were either TPN dependent (n¼13) or had enteropathy refractory to at least 3 immunosuppressive agents (n¼13) prior to transplant. Patients with overt primary immunodeficiency were excluded. 8 of 26 patients had a confirmed pathogenic mutation identified (IPEX, XIAP, IL10, IL10Ra) and 18/26 remain genetically undefined. 11 patients (42%) had previously undergone gut resections +/-defunctioning stoma formation and 63% had suffered life threatening complications prior to transplant (sepsis, lymphoproliferative disease, vasculitis). 22 SCTs were performed with fully HLA matched donors (8 family, 14 unrelated), and 5 with 9/10 mismatched donors. With exception of 2 sibling donor grafts conditioned, all patients received reduced toxicity conditioning, the majority with alemtuzumab 1mg/kg, fludarabine 150mg/m 2 + either treosulphan 42g/m 2 (n¼12) or melphalan 140mg/m 2 (n¼10). Transplant related mortality was 23% (n¼6) from GVHD, conditioning toxicity, viral infections and pulmonary hypertension. One patient died from diabetic ketoacidosis unrelated to SCT following a successful transplant. 96% of patients engrafted, but one patient required a second graft following rejection. The majority of patients (22/26) had full donor chimerism at last follow-up, and the remaining 4 patients have stable mixed chimerism with 73-94% donor chimerism within the lymphoid lineage. 8 patients (30%) developed significant aGVHD but the incidence of cGVHD was low (n¼1, 4%). At a median follow-up of 51 months, 19 patients are alive, 17 of whom have had sustained improvement in their enteropathy. 8 surviving patients (89%) on TPN pre-transplant have now discontinued and 14 (78%) are off all immunosuppression. Our data demonstrate that reduced toxicity conditioned SCT can cure the majority of patients with IEOC even in the absence of a defined genetic defect. We believe that given the severity of this condition, SCT offers patients major improvement in quality of life at an acceptable risk of toxicity and that further studies of this approach in well-defined patients are warranted.

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