A Phase II study evaluated Revlimid ( Lenalidomide ) in previously treated patients with myelofibrosis, a rare blood disorder that can be fatal if untreated.
Clinical data were reported during the 47th American Society of Hematology ( ASH ) Meeting in Atlanta.

Myelofibrosis ( also called agnogenic myeloid metaplasia ) is a myeloproliferative disorder in which the bone marrow is initially over-active but then develops fibrosis.

The study, lead investigator Jorge Cortez, of the University of Texas, M.D. Anderson Cancer Center, Houston, enrolled forty-one patients with myelofibrosis, primary or associated with myeloproliferative disorders, with a platelet count of at least 30x10(9)/L.

The patients with a median age of 65 ( range, 42 to 83 ) received Lenalidomide at 10 mg/day orally ( 5 mg daily for patients with a platelet count less than 100,000 at the start of the study ).

Patients may have received prior therapies, but were excluded if they had known hypersensitivity to Thalidomide.
Thirty-six patients ( 88% ) had received prior therapy for myelofibrosis , including thirteen Thalidomide patients ( 32% ), thirteen Hydroxyurea patients ( 32% ), eleven Interferon patients ( 27% ), ten Anagrelide patients ( 24% ), and six Erythropoietin patients ( 15% ).

Thirty-two patients were evaluable for response or toxicity.

Responses were observed in nineteen patients ( 46% ), including complete response ( CR ) achieved in three patients defined by normalization of Hgb and WBC, respectively.
Partial response ( PR ) was achieved in five patients as a result of improvement in platelets and Hgb, +/- spleen, and hematologic improvement was observed in eleven patients based on improvement in platelets, spleen, WBC and BM blasts.
Five of thirteen transfusion-dependent patients became transfusion independent.

The median time to response was six weeks ( range, 1 to 22 ). Responses were sustained for a median of thirty-one weeks ( range, 1 to 40 weeks ).

Therapy was well tolerated and side-effects clinically manageable, with the more common toxicities being rash in sixteen patients ( 39% ), pruritus in nine patients ( 22% ), thrombocytopenia in eleven patients ( 29% ), fatigue in three patients ( 7% ), and neutropenias in thirteen patients ( 32% ).
Eight patients ( 20% ) have required dose reduction and four discontinued therapy because of toxicity.

Source: Celgene, 2005


XagenaMedicine2005