Rapid rituximab administration: Safety of 60-minute infusions in malignant and benign haematological disease.

INTRODUCTION: Rituximab is a chimeric monoclonal antibody used to treat a range of malignant and benign haematological conditions. To minimise the risk of infusion-related toxicity, initial infusions are administered slowly over 4-6 h. In the absence of significant reactions, subsequent doses are often administered over an off-label rate of 90 min. In response to emergent data, our site adopted the use of rapid 60-min infusions for third and subsequent doses. This study aimed to review the safety and ongoing feasibility of 60-min rituximab infusions following institutional practice change. METHODS: Pharmacy dispensing records were used to identify all rituximab infusions dispensed under the direction of a haematologist between 1 January 2023 and 30 June 2023. Electronic medical records were reviewed retrospectively to characterise the incidence of infusion reactions. RESULTS: Eight-two patients received a total of 262 rituximab infusions, including 54 patients who received a total of 113 rapid 60-min infusions. No infusion-related reactions were observed with 60-min administration. Five patients who experienced grade 1-2 infusion reactions with their first or second dose of rituximab safely received 60-min infusions for third and subsequent doses without additional premedication. Indications for treatment included non-Hodgkin's lymphoma (76.99%), non-malignant disease states (17.70%), chronic lymphocytic leukaemia (3.54%) and post-transplant lymphoproliferative disorder (1.77%). CONCLUSION: In the absence of severe reactions to initial and second doses, administration of rituximab over 60 min is well tolerated in patients with malignant and benign haematological disease.

Intravitreal implantation of TPP1-transduced stem cells delays retinal degeneration in canine CLN2 neuronal ceroid lipofuscinosis.

The CLN2 form of neuronal ceroid lipofuscinosis is a neurodegenerative disease that results from mutations in the TPP1 gene. Affected children exhibit progressive declines in most neurological functions including vision. Functional declines are accompanied by progressive brain and retinal atrophy. TPP1 encodes the soluble lysosomal enzyme tripeptidyl peptidase-1 (TPP1). Dachshunds with a TPP1 null mutation exhibit a disorder very similar to human CLN2 disease. Periodic infusion of recombinant TPP1 protein or a single injection of a TPP1 gene therapy vector into the cerebrospinal fluid of affected dogs significantly delays the onset and progression of neurological signs but does not slow vision loss or retinal degeneration. Studies were conducted to determine whether intravitreal implantation of autologous bone marrow derived stem cells transduced with a TPP1 expression construct would inhibit retinal degeneration in the canine model. A single injection of the transduced cells at an early stage in the disease progression substantially inhibited the development of disease-related retinal function deficits and structural changes. No adverse effects of the treatment were detected. These findings indicate that ex vivo gene therapy using autologous stem cells is an effective means of achieving sustained delivery of therapeutic compounds to tissues such as the retina for which systemic administration would be ineffective.

AAV gene transfer delays disease onset in a TPP1-deficient canine model of the late infantile form of Batten disease.

The most common form of the childhood neurodegenerative disease late infantile neuronal ceroid lipofuscinosis (also called Batten disease) is caused by deficiency of the soluble lysosomal enzyme tripeptidyl peptidase 1 (TPP1) resulting from mutations in the TPP1 gene. We tested whether TPP1 gene transfer to the ependyma, the epithelial lining of the brain ventricular system, in TPP1-deficient dogs would be therapeutically beneficial. A one-time administration of recombinant adeno-associated virus (rAAV) expressing canine TPP1 (rAAV.caTPP1) resulted in high expression of TPP1 predominantly in ependymal cells and secretion of the enzyme into the cerebrospinal fluid leading to clinical benefit. Diseased dogs treated with rAAV.caTPP1 showed delays in onset of clinical signs and disease progression, protection from cognitive decline, and extension of life span. By immunostaining and enzyme assay, recombinant protein was evident throughout the brain and spinal cord, with correction of the neuropathology characteristic of the disease. This study in a naturally occurring canine model of TPP1 deficiency highlights the utility of AAV transduction of ventricular lining cells to accomplish stable secretion of recombinant protein for broad distribution in the central nervous system and therapeutic benefit.