Yttrium 90 ibritumomab tiuxetan (Zevalin®): A new bullet in the fight against malignant lymphoma?

Yttrium-90 ibritumomab tiuxetan as a single agent in patients with pretreated B-cell lymphoma: evaluation of the long-term outcome

BACKGROUND

Based on historical data on the role of radioimmunotherapy (RIT) in pretreated non-Hodgkin lymphoma, we reviewed our hospital's clinical database.

PATIENTS AND METHODS

Between 2005 and 2008, 57 patients previously treated with at least 1 rituximab-containing chemotherapy were treated with Yttrium-90-labeled ibritumomab tiuxetan ((90)Y-IT). The median number of pretreatments was 3 (range, 1-9 pretreatments). A total of 46 patients had stage III/IV disease (31 with bone marrow involvement); 6 had bulky disease. According to histology, 53 were follicular lymphoma (FL), 2 were marginal zone lymphoma, and 2 were small lymphocytic lymphoma.

RESULTS

Overall response rate was 93% (53 of 57); complete response (CR) rate was 70% (40 of 57). Twenty-six of 40 patients (65%) who obtained a CR are in continuous CR (CCR) with a median follow-up of 20 months (range, 10-42 months); 4 of them still maintain their CCR after 36 months. All patients achieving a CCR had FL, and 21 of them with stage III/IV disease; 12 of 26 had been heavily pretreated (>or= 3 previous treatments), and 2 had had autologous stem cell transplantation. Toxicity was primarily hematologic and mostly transient; no grade 4 extrahematologic toxicity was observed.

CONCLUSION

This study confirms the safety and high efficacy of (90)Y-IT RIT in heavily pretreated FL patients, with the possibility of having a subset of long-term responders.

Acute orbitocranial inflammation following radioimmunotherapy for non-Hodgkin lymphoma

Radioimmunotherapy with yttrium-90-ibritumomab tiuxetan may result in hemorrhagic tumor necrosis with acute orbital and intracranial inflammation.

ING proteins as potential anticancer drug targets

Recent emerging evidence suggests that ING family proteins play roles in carcinogenesis both as oncogenes and tumor suppressor genes depending on the family members and on cell status. Previous results from non-physiologic overexpression experiments showed that all five family members induce apoptosis or cell cycle arrest, thus it had been thought until very recently that all of the family members function as tumor suppressor genes. Therefore restoration of ING family proteins in cancer cells has been proposed as a treatment for cancers. However, ING2 knockdown experiments showed unexpected results: ING2 knockdown led to senescence in normal human fibroblast cells and suppressed cancer cell growth. ING2 is also overexpressed in colorectal cancer, and promotes cancer cell invasion through an MMP13 dependent pathway. Additionally, it was reported that ING2 has two isoforms, ING2a and ING2b. Although expression of ING2a predominates compared with ING2b, both isoforms confer resistance against cell cycle arrest or apoptosis to cancer cells, thus knockdown of both isoforms is critical to remove this resistance. Taken together, these results suggest that ING2 can function as an oncogene in some specific types of cancer cells, indicating restoration of this gene in cancer cells could cause cancer progression. Because knockdown of ING2 suppresses cancer cell invasion and induces apoptosis or cell cycle arrest, ING2 may be an anticancer drug target. In this brief review, we discuss possible clinical applications of ING2 with the latest knowledge of molecular targeted therapies.