Exceptional response to neoadjuvant targeted therapy with the selective RET inhibitor selpercatinib in RET-fusion-associated sarcoma.

With the increasing use of next-generation sequencing, highly effective targeted therapies have been emerging as treatment options for several cancer types. Recurrent gene-fusions have been recognized in sarcomas; however, options for targeted therapy remain scarce. Here, we describe a case of a sarcoma, associated with a RET::TRIM33-fusion gene with an exceptional response to a neoadjuvant therapy with the selective RET inhibitor selpercatinib. Resected tumor revealed subtotal histopathologic response. This is the first report of successful targeted therapy with selpercatinib in RET-fusion-associated sarcomas. As new targeted therapies are under development, similar treatment options may become available for sarcoma patients.

Outcome of FLT3-ITD-positive acute myeloid leukemia: impact of allogeneic stem cell transplantation and tyrosine kinase inhibitor treatment.

BACKGROUND: Activating mutations of the receptor tyrosine kinase FLT3 (fms-related tyrosine kinase 3) reflect the most frequent molecular aberration in acute myeloid leukemia (AML). In particular, FLT3 internal tandem duplications (FLT3-ITD) are characterized by an unfavorable prognosis and allogeneic stem cell transplantation (allogeneic SCT) in first complete remission is recommended. In case of imminent or frank relapse following allogeneic SCT, treatment with FLT3 tyrosine kinase inhibitors (TKI) constitutes a promising clinical approach to induce hematologic remission without conventional chemotherapy. PATIENTS AND METHODS: We retrospectively analyzed the response to induction chemotherapy and the outcome of 76 patients with FLT3-ITD-positive AML including 50 patients who underwent allogeneic SCT. Furthermore, efficacy of TKI treatment was evaluated in 18 patients (median age 54 years, range 21-74) with relapsed or refractory FLT3-ITD-positive AML. RESULTS: Response to induction chemotherapy in 76 FLT3-ITD-positive AML patients was characterized by a complete remission (CR) rate of 68%. In total, 50 of 76 patients (66%) underwent allogeneic SCT including 40 patients (80%) in CR. Relapse of AML was observed in 21 of 47 patients (45%) after allogeneic SCT with a median relapse-free survival (RFS) of 13 months (range 3-224) for patients with CR prior to or at day +30 after SCT. Myeloablative conditioning resulted in an improved median RFS of 29 months (4-217) as compared to a reduced intensity conditioning protocol prior to allogeneic SCT with a RFS of 8 months (1-197, P = 0.048), respectively. Median OS of FLT3-ITD-positive AML was 17 months (5-225) for patients who received an allogeneic SCT as compared to 9 months (1-184) for patients who did not undergo SCT. Response of FLT3-ITD-positive AML to sorafenib was characterized by only 3 of 18 patients achieving a bone marrow response (17%), while there was no response to second-line treatment with ponatinib. CONCLUSION: This "real-life" data reflect the continuing challenge of FLT3-ITD-positive AML and confirm the poor outcome even after allogeneic SCT. Furthermore, efficacy of TKI treatment of relapsed or refractory FLT3-ITD AML is still limited and requires substantial improvement, e.g., by the introduction of second-generation inhibitors targeting constitutively active FLT3.

Efficacy of antifungal prophylaxis with oral suspension posaconazole during induction chemotherapy of acute myeloid leukemia.

BACKGROUND: Severe infectious complications reflect a continuing problem in patients with acute myeloid leukemia (AML). Based on data from a randomized clinical trial demonstrating a reduction of proven and probable invasive fungal disease (IFD), posaconazole has been approved for prophylaxis of fungal infections in AML patients during induction chemotherapy. Nevertheless, recently published observational studies show contradictory results concerning the efficacy of posaconazole in this clinical setting. Furthermore, oral suspension posaconazole is associated with an unpredictable bioavailability that especially depends on nutritional factors or gastric pH value. PATIENTS AND METHODS: We retrospectively analyzed the impact of posaconazole prophylaxis in 70 consecutively evaluable AML patients who underwent induction chemotherapy at a tertiary care hospital. The incidence of IFD classified as proven, probable or possible, antifungal therapy including empiric treatment in high-risk patients and tolerability of posaconazole were determined. In addition, important clinical cofactors such as co-treatment with proton pump inhibitors and risk factors for pneumonia were analyzed in this study. RESULTS: We can demonstrate that posaconazole is well tolerated and had to be stopped in only six patients (8.6%). The overall incidence of IFD was 30% including two patients with proven (2.8%), four patients with probable (5.7%) and 15 patients with possible IFD (21.4%). Importantly, 24 out of 49 patients (49.0%) who did not fulfill the criteria of IFD received empiric antifungal therapy. Including patients classified as possible IFD, 39 of 70 patients (55.7%) underwent at least first-line antifungal treatment. CONCLUSION: Our "real-life" data obtained from 70 AML patients after induction chemotherapy demonstrate the frequent necessity of systemic antifungal treatment despite prophylaxis with oral suspension posaconazole.