Anti-CD38 Therapy with Daratumumab for Relapsed/Refractory CD20-Negative Diffuse Large B-Cell Lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common and one of the most aggressive subtypes of non-Hodgkin's lymphomas. Front-line therapy consists of chemotherapy in combination with anti-CD20 monoclonal antibody rituximab. Relapses after rituximab-based regimen have poor prognosis and call for new treatment options. Immunohistochemistry analysis of relapsed DLBCL often reveal CD20-negative lymphoma, which limits repeated use of rituximab in combination with salvage chemotherapy. CD38 is a surface antigen that binds to CD38, CD31/PECAM-1 and hyaluronic acid. CD38 is an important mediator of signal transmission from the microenvironment into the cell. Anti-CD38 monoclonal antibody daratumumab has been approved for the treatment of multiple myeloma. Expression of CD38 on the surface of DLBCL is highly variable (compared to strong expression on myeloma cells), but can be easily assessed by flow cytometry or immunohistochemistry. A patient-derived xenograft (PDX) model of CD20-negative, CD38-positive DLBCL derived from a patient with rituximab-refractory DLBCL was used for in vivo experiments. We demonstrated that daratumumab suppressed growth of subcutaneous PDX tumours significantly more effectively than rituximab. Analysis of tumours obtained from mice treated with daratumumab revealed down-regulation of surface CD38, suggesting endocytosis of CD38-daratumumab complexes. The results suggest a potential clinical use of daratumumab in combination with salvage chemotherapy in patients with relapses of CD20-negative DLBCL. In addition, daratumumab might potentially serve as a suitable antibody moiety for derivation of antibodydrug conjugates for the targeted delivery of toxic payloads to the lymphoma cells.

Single-agent cytarabine is insufficient for the treatment of human mantle cell lymphoma in mouse xenograft model.

Mantle cell lymphoma is an aggressive type of B-cell non-Hodgkin lymphoma with adverse prognosis. It was demonstrated that alternation of CHOP and DHAP chemotherapy improved outcome of mantle cell lymphoma patients. However, which components of DHAP, cisplatin, cytarabine, or both, were responsible for the improved outcome remained unclear. To answer this question, antitumor efficacies of equally toxic doses of cytarabine, cisplatin, and three different combinations were compared in vivo using mouse xenograft models of mantle cell lymphoma. We demonstrated that cisplatin, alone or with cytarabine, is significantly superior to single-agent cytarabine in both eliminating lymphoma cells and suppressing their proliferation rate.

Trefoil factor family (TFF) proteins as potential serum biomarkers in patients with metastatic colorectal cancer.

Trefoil factor family (TFF) is composed of three secretory proteins (TFF1, TFF2 and TFF3) that play an important role in mucosal protection of gastrointestinal tract. Their overexpression in colorectal tumors seems to be associated with more aggressive disease. We collected serum samples from 79 healthy controls and 97 patients with metastatic colorectal cancer at the time of diagnosis or at progression. Serum levels of TTF1-3, CEA and CA19-9 were measured by ELISA. Serum TFF1 and TFF3 levels were significantly higher in patients with colorectal cancer compared to healthy controls (p < 0.0001). Moreover, serum levels of TFF3 correlated with extent of liver involvement in patient without pulmonary metastases and patients with higher TFF3 levels had significantly worse outcome (p < 0.0001). Compared to CEA and CA19-9, TFF3 had higher sensitivity and the same specificity. Our results indicate that TFF3 is an effective biomarker in patients with metastatic colorectal cancer with higher sensitivity than CEA a CA19-9. TFF3 levels strongly correlate with extension of liver disease and seem to have prognostic value.