Industry Update: Bosutinib Produces Molecular Response as First-line CML Therapy

December 7, 2010

Nplate sustains platelet counts in patients with adult chronic immune (idiopathic) thrombocytopenic purpura (ITP) while single-dose Zevalin offers survival advantage in non-Hodgkin’s lymphoma.

Bosutinib produces molecular response as first-line CML therapy

Pfizer Oncology’s bosutinib (SK1-606) turned in solid results for major molecular response compared with imatinib (Gleevec) in newly diagnosed chronic myeloid leukemia (CML), but did not bring about superior complete cytogenetic response (CCyR), according to the outcome of a phase III trial.

The BELA* study enrolled 502 adult patients with Philadelphia chromosome-positive CML. According to the results, 39% of the patients in the bosutinib arm experienced MMR vs 26% in the imatinib arm. For CCyR, the rate at one year for the bosutinib arm was 68% vs 70% for the imatinib arm (P = .601) in the intent-to-treat population.

The most frequently reported all-grade drug-related adverse event with bosutinib was diarrhea (66%). The most frequent grade 3/4 adverse events with bosutinib included diarrhea (8%) and rash (2%), although no patients in the bosutinib arm discontinued therapy due to diarrhea, according to Pfizer Oncology (ASH 2010 abstract 208).

*BELA = Bosutinib Efficacy and safety in chronic myeloid LeukemiANplate maintains platelet count in autoimmune disorder over long term

Romiplostim (Nplate), from Amgen, effectively maintained platelet counts in patients with adult chronic immune (idiopathic) thrombocytopenic purpura (ITP), according to the final analysis of a five-year open-label extension study.

Romiplostim maintained platelet counts within a range of 50,000 to 200,000 platelets per microliter in the majority of adult patients with chronic ITP with minimal decreased or increased dose adjustments for up to 277 weeks. Over the course of the study, a count of ≥50,000 platelets per microliter was achieved by 95% of 292 patients receiving Romiplostim, and the median platelet count remained ≥50,000 platelets per microliter for the duration of the study after week one. Patients were treated for a median of 78 weeks with a maximum duration of 277 weeks. Thirty-three percent of patients had previously undergone splenectomy (ASH 2010 abstract 68).


Single-dose Zevalin demonstrates multiple-month PFS for NHL

Patients with previously untreated follicular non-Hodgkin’s lymphoma who received a single-dose infusion of ibritumomab tiuxetan (Zevalin) after partial or complete response to first-line chemotherapy had a nearly three-year advantage in median progression-free survival (PFS) compared with patients treated with either chemotherapy alone or chemotherapy plus rituximab (Rituxan). Patients in the FIT* trial were followed for a median of 66.2 months and the PFS came in at 49 months for the ibritumomab arm and 14 months for chemotherapy alone or the combination therapy (ASH 2010 abstract 594).

Ibritumomab is a CD20-directed radiotherapeutic antibody. The therapeutic regimen consists of three components: rituximab, Indium-111 radiolabeled ibritumomab for imaging, and Yttrium-90 radiolabeled ibritumomab for therapy.

Spectrum Pharmaceuticals plans to submit data for consideration to the FDA about removal of the current bioscan requirement before administration of the product.

*FIT = First-line Indolent Trial