Use of Rituximab in Opsoclonus-Myoclonus in Children With Neuroblastoma

Opsoclonus-myoclonus ataxia syndrome (OMS) is a rare immune mediated paraneoplastic syndrome
that occurs in approximately 2 to 3% of children with neuroblastoma. Children with
neuroblastoma associated opsoclonus-myoclonus tend to have a favorable prognosis from the
standpoint of the cure of their cancer. Unfortunately,approximately two-thirds of this
subgroup of patients are left with long term sequellae of the syndrome, including residual
symptoms of opsoclonus, myoclonus, ataxia, learning difficulties and disturbance of sleep
and mood.

Multiple lines of evidence indicate an immune mechanism to this rare disorder. This includes
occurence of OMS in the post-infectious state, aggressive lymphocytic infiltration of the
tumor in children with OMS, and documented responses to therapries that act through
suppression of the immune system.

The current study utilizes four weekly doses of anti-CD 20 antibody (rituximab) to treat
children with refractory OMS. Refractory disease is defined as continued symptoms of OMS
despite surgical resection of the tumor and a minimum of one month of steroid therapy.

All patients have baseline OMS evaluation and detailed neurocognitive testing with all
studies being repeated at the completion of the four weekly infusions. OMS testing is
repeated at Month 3. OMS testing and detailed neurocognitive testing is conducted at 6
months intervals until 2 years from the initial infusion.

The goal of the study is to utilize this novel therapy to improve long term neurologic and
neurodevelopmental outcome in children with refratory neuroblastoma associated
opsoclonus-myoclonus.

Inclusion Criteria:

Pathologic confirmation of diagnosis of neuroblastoma Surgical resection of primary tumor
Symptoms of OMS despite a minimum of one month of steroid therapy Must meet all laboratory
criteria to demonstrate adequate organ function -

Exclusion Criteria:

Patients currently receiving systemic chemotherapy for treatment of neuroblastoma Patients
with documented active infection Patients who are HIV, Hep B or Hep C positive Organ
toxicity from any prior therapy or surgical intervention must be resolved prior to study
entry