The role of relative lymphocyte count as a biomarker for the effect of catumaxomab on survival in malignant ascites patients: results from a phase II/III study.

Abstract

PURPOSE:

We report the role of relative lymphocyte count (RLC) as a potential biomarker with prognostic impact for catumaxomab efficacy and overall survival (OS) based on a post hoc analysis of the pivotal phase II/III study of intraperitoneal catumaxomab treatment of malignant ascites.

EXPERIMENTAL DESIGN:

The impact of treatment and RLC on OS was evaluated using multivariate Cox models. Kaplan-Meier and log-rank tests were used for group comparisons. Survival analyses were performed on the safety population [patients with paracentesis plus ≥ 1 dose of catumaxomab (n = 157) and paracentesis alone (n = 88)]. Determination of the optimal cutoff value for RLC was based on five optimality criteria.

RESULTS:

OS was significantly longer with catumaxomab versus paracentesis alone (P = 0.0219). The 6-month OS rate with catumaxomab was 28.9% versus 6.7% with paracentesis alone. RLC had a positive impact on OS and was an independent prognostic factor (P < 0.0001). In patients with RLC > 13% (n = 159: catumaxomab, 100 and control, 59), catumaxomab was associated with a favorable effect on OS versus paracentesis alone (P = 0.0072), with a median/mean OS benefit of 41/131 days and an increased 6-month survival rate of 37.0% versus 5.2%, respectively. In patients with RLC ≤ 13% at screening (n = 74: catumaxomab, 50 and control, 24), the median (mean) OS difference between the catumaxomab and the control group was 3 (16) days, respectively (P = 0.2561).

CONCLUSIONS:

OS was significantly improved after catumaxomab treatment in patients with malignant ascites. An RLC > 13% at baseline was a significant prognostic biomarker.

• Authors: Markus M Heiss, Michael A Ströhlein, Carsten Bokemeyer, Dirk Arnold, Simon L Parsons, Diane Seimetz, Horst Lindhofer, Elisabeth Schulze, Michael Hennig
• Journal: Clinical cancer research : an official journal of the American Association for Cancer Research (Clin Cancer Res) Vol. 20 Issue 12 Pg. 3348-57 (Jun 15 2014) ISSN: 1557-3265 [Electronic] United States
• PMID: 24714773 (Publication Type: Clinical Trial, Phase II, Clinical Trial, Phase III, Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: ©2014 American Association for Cancer Research.

Chemical References

• Antibodies, Bispecific
• Biomarkers
• catumaxomab

Topics

• Antibodies, Bispecific (therapeutic use)
• Ascites (blood, drug therapy, mortality, pathology)
• Biomarkers (analysis)
• Case-Control Studies
• Follow-Up Studies
• Humans
• Injections, Intraperitoneal
• Lymphocyte Count
• Neoplasm Staging
• Paracentesis (mortality)
• Prognosis
• Survival Rate