Subcutaneous injections of low doses of humanized anti-CD20 veltuzumab: a phase I study in chronic lymphocytic leukemia*

Abstract

To evaluate the potential of subcutaneous (SC) injections with anti-CD20 antibody veltuzumab in chronic lymphocytic leukemia (CLL), 21 patients received 80, 160, or 320 mg injections every 2 weeks × 4 doses (n = 11) or 160 or 320 mg twice-weekly × 16 doses (n = 10). Treatment was well tolerated with only occasional, mild-moderate, transient injection reactions. Lymphocytosis decreased in all patients (maximum decrease, 5–91%), with 12 patients obtaining >50% decreases. Of 14 patients with lymphadenopathy on CT imaging, 5 (36%) achieved 14–61% reductions (sum of perpendicular diameters). By NCI-WG criteria, two patients achieved partial responses (10%). SC veltuzumab appeared active in all dose groups, with no obvious exposure-response relationship, despite cumulative doses ranging from 320–5120 mg. Overall median progression-free survival was 7.7 months; three patients remained progression-free >1 year (2 ongoing at 2-year study completion). These data suggest further studies of SC veltuzumab in CLL are warranted.

Keywords:

• Antibody
• CD20
• chronic lymphocytic leukemia
• subcutaneous therapy
• veltuzumab

Acknowledgements

Research support for this study was provided by Immunomedics, Inc. to the participating institutions. Clinicaltrials.gov registration number NCT00546793.

Potential conflict of interest

Disclosure forms provided by the authors are available with the full text of this article at http://dx.doi.org/10.3109/10428194.2015.1085531.

Supplementary material available online

Supplementary Figures S1 & S2