FIP1L1-PDGFRA fusion

P3, N=134, Active, not recruiting, AstraZeneca | Trial completion date: Sep 2026 --> Dec 2026

We sequenced genomic DNA from patients (n = 20) with a known or suspected TK gene fusion and identified rearrangements in 18 cases, including all cases with a known TK fusion, typical and atypical BCR::ABL1 rearrangements, an 843Kb deletion causing a FIP1L1::PDGFRA fusion, novel AGAP2::PDGFRB and NFIA::PDGFRB fusions, and a complex CCDC88C::PDGFRB rearrangement with multiple translocation events. The approach was fast (<72 h/sample from DNA to result), flexible with minimal hands-on laboratory time, and provided accurate, patient-specific characterisation of genomic breakpoints.

Meanwhile, the FIP1L1::PDGFRA fusion gene detection results strongly support the use of molecular diagnosis in ABL. In addition, the patient successfully achieved a complete response to treatment and was followed for a year and a half without relapse, thus offering valuable insights for treatment strategies in similar cases.

Case 6 experienced symptom relief after glucocorticoids and hydroxyurea treatment, followed by complete remission after chemotherapy with the cytarabine (20 mg q12 h × 14 days), idarubicin (5 mg on days 2-12 every other day), and G-CSF (adjusted based on blood counts) regimen. The remaining three patients demonstrated improvement after glucocorticoid treatment. Except for case 6, the other patients were still alive, with case 4 relapsing at 28 months after imatinib discontinuation and relieved after treatment re-initiation.

P3, N=134, Active, not recruiting, AstraZeneca | Trial completion date: Apr 2027 --> Sep 2026

The findings highlight the importance of accurate classification and tailored management of HE and HES, which are crucial for preventing organ damage and improving quality of life. Ongoing clinical trials and research will expand therapeutic options, clarify underlying mechanisms, and address current unmet needs.

This case highlights that Loeffler endocarditis can present as the primary and sole manifestation of chronic eosinophilic leukaemia. Effective collaboration between cardiologists and internists is crucial for timely diagnosis and comprehensive management, ultimately resulting in enhanced outcomes.

Identification of FIP1L1::PDGFRA rearrangements is important as they enable treatment with a tyrosine kinase inhibitor, which has significantly improved the overall prognosis for PDGFRA-rearranged neoplasms. Prospective studies assessing imatinib dosage, duration, and long-term safety are warranted in this cohort.

P3, N=117, Active, not recruiting, AstraZeneca | Recruiting --> Active, not recruiting | Trial primary completion date: Sep 2024 --> May 2025

P3, N=120, Recruiting, AstraZeneca | Trial completion date: Nov 2024 --> Nov 2026 | Trial primary completion date: Nov 2023 --> May 2024