Program: Oral and Poster Abstracts
Session: 634. Myeloproliferative Syndromes: Clinical: Poster I
Methods: The charts of patients treated at Texas Children's Hospital from December 2009 to present were reviewed in accordance with IRB-approved protocols at Baylor College of Medicine. Patients were selected for hydroxyurea therapy based on specific clinical characteristics, including low-risk single-system disease on presentation, recurrent/refractory disease following standard of care front-line therapy, and intolerance of other therapies. Treatment response was reported using the criteria established in the Histiocyte Society Evaluation and Treatment Guidelines.
Results: Fourteen patients, ranging from 1 month to 66 years old, previously receiving 1-5 alternate regimens, have received hydroxyurea therapy. To date, patients have been on therapy for an average of 10.4 months, with dose ranging from 750 mg to 3000 mg daily (titrating for an ANC of 1500). Data shows that 57% of patients had improvement in symptoms/regression of disease, and we will continue to follow responses in the entire cohort of patients. One patient had anemia requiring dose reduction, but therapy was otherwise well tolerated.
Conclusion: Hydroxyurea demonstrated activity against LCH with minimal toxicity in patients with relapsed or refractory LCH following initial systemic chemotherapy. Disease control improved in the majority of patients on hydroxyurea monotherapy. A role for hydroxyurea in therapy of LCH patients is warranted. Chronic use of hydroxyurea is well tolerated, making it an ideal agent to investigate for the role of maintenance therapy. Furthermore, use of hydroxyurea in combination with other therapies is well established in other diseases, and should be investigated in patients with LCH.
Number of Patients |
14 |
|
Number of Regimens prior to Hydroxyurea |
|||
Male |
4 |
Mean |
2.8 |
|||
Female |
10 |
Range |
1 to 5 |
|||
|
Pretreatment Regimen |
|||||
Age at Diagnosis |
Methotrexate, 6MP, Prednisone |
9 |
||||
Mean |
31 y 8 mo |
Cytarabine |
7 |
|||
Range |
1 mo – 66 y |
Vinblastine, Prednisone, MTX, 6MP |
4 |
|||
|
Cladribine |
3 |
||||
Time from Diagnosis to Start of Hydroxyurea |
Etoposide |
2 |
||||
Mean |
8 y 8 mo |
Prednisone |
2 |
|||
Range |
4 mo – 26 y |
AKT inhibitor |
1 |
|||
|
Campath |
1 |
||||
Duration of Hydroxyurea |
Clofarabine |
1 |
||||
Mean |
7.4 mo |
Narrow Spec UV |
1 |
|||
Range |
1 mo – 17 mo |
Radiation Therapy |
1 |
|||
|
||||||
Response to Therapy |
||||||
Complete Resolution |
0 |
|
Intermediate/Stable |
2 |
||
Better/Regression |
8 |
Worse |
1 |
|||
Intermediate/Mixed |
0 |
Unknown |
3 |
|||
Disclosures: Off Label Use: Hydroxyurea -- used for myeloproliferative neoplasms, but not traditionally for Langerhans Cell Histiocytosis. Allen: NovImmune: Consultancy , Other: unpaid ; Roche: Consultancy , Other: unpaid .
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