About Lymphoma | Advocacy | Art | CAM | Clinical trials 
Doctors - Experts - Centers | Guidelines at Diagnosis | News
Risk Factors | Side Effects | Statistics | Support | Symptoms |
Tests | Treatments | Types of Lymphoma | How to Help

Guidelines at Diagnosis | About Clinical Trials

Search Site

evidence-based support and information


Side Effects or Symptoms > HAMA (human anti-mouse antibodies)

Last update: 02/18/2013



Fatigue | Quick Reference | Resources & Research News

HAMA  Human Anti-Mouse Antibodies. A mouse antibody administered to a human is seen by the human immune system as a foreign protein (antigen). The human immune system then generates its own human antibodies against the introduced mouse antibody (the HAMA response). 

The HAMA response can create problems such as allergic-like reaction to the mouse antibody, rapid removal of the mouse antibody, and weak ability to recruit human immune system processes necessary to clear the targeted antigen (e.g. tumor cell). 

The first may generate additional health problems in a patient while the latter two reduce the efficacy of the mouse antibody as a therapeutic. - Genentech  gene.com 

"Patients receiving murine antibodies, particularly in high amounts, may form human antibodies against these foreign proteins or human antimouse antibodies (HAMA), which usually occur within 23 wk after the first mAb administration and within hours or days after a repeated administration. 

Even after repeated mAb administrations, HAMA formation usually does not cause significant adverse reactions, although flu-like symptoms or mild-to-moderate anaphylactic reactions (e.g., urticaria, bronchospasm) may occur, which are easily treatable with antihistamines or corticosteroids (*)."


* Wahl RL, Zasadny KR, Estes J, et al. Single center experience with iodine I131
tositumomab radioimmunotherapy for previously untreated follicular lymphoma
(FL) [abstract]. J Nucl Med. 2000;41(suppl):79P.

HAMA as a Side Effect of Treatment 

"About one-third of patients with relapsed B-cell malignancies develop human 
anti-mouse antibody (HAMA) following mouse antibody treatment" 

- Survival benefit associated with human anti-mouse antibody (HAMA) in patients with B-cell malignancies - springerlink.com
"Although approximately 10% of patients treated with tositumomab and iodine I 131 tositumomab (bexxar)  developed human-anti-mouse antibodies, treatment with  tositumomab does not preclude the  administration of subsequent chimeric (mouse-human) antibody therapies."  
- A clinical and scientific overview of tositumomab and iodine I 131 tositumomab. 
Semin Oncol. 2003 Apr;30(2 Suppl 4):22-30. Review. PMID: 12728404 
If a person makes HAMA, they could have a serious allergic reaction to any other drug or 
diagnostic test that was made from mouse protein, or it could affect how well the drug or 
diagnostic test worked. 

Bexxar for NHL - http://www.bexxar.com/patients/bexxar_patientsmain.html 
Does Development of HAMA After Tositumomab (Bexxar) Preclude Subsequent Therapy 
With Rituximab (Rituxan)? -

Development of HAMA can occur after exposure to tositumomab, especially in patients who have not received prior chemotherapy for their disease. 

In this group who receive "front-line" tositumomab, HAMA antibodies have been demonstrated in as many as 64%. In a study by Mark S. Kaminski, from the University of Michigan, Ann Arbor, Michigan, and colleagues,[5] 22 patients with HAMA responses to tositumomab were studied, and 6 were found to have high titer (> 500 mg/mL) antibody. 

Thirteen of these patients subsequently received rituximab. Although response rates were 
not reported, it is important to note that there was no evidence of increased severity or frequency of infusion reactions. Therefore, it seems that rituximab can be given safely after developmentof HAMA responses to tositumomab.
- Alexandra M. Levine, MD   Robert S. Mocharnuk, MD 
Rituximab, Tositumomab (Bexxar), Ibritumomab (Zevalin): And the Winner Is... 
 M (free login req.) 




HAMA and pet mice? Also see www.cap.org  
Resources & Research News:
Return to top


Survival benefit associated with human anti-mouse antibody (HAMA) in patients with B-cell malignancies. Cancer Immunol Immunother. 2006 Dec;55(12):1451-8. Epub 2006 Feb 22. PMID: 16496145

Patients with B-cell malignancies that developed high HAMA titers had longer survival that was not explained by risk factors or histologic grade, suggesting the importance of the immune system.
Disclaimer:  The information on Lymphomation.org is not intended to be a substitute for 
professional medical advice or to replace your relationship with a physician.
For all medical concerns,  you should always consult your doctor. 
Copyright 2004,  All Rights Reserved.