N. Dursun et al.
changes in administrative processes and reimbursement
policies. Unlike that study, however, we did not use a
fixed conversion ratio of OnaBoNT-A to AboBoNT-A,
instead preferring to base our dosing decisions on the
child’s individual presentation at that time. In recent
years, there has been considerable disagreement bet-
ween the various studies conducted on this issue and
many authors have concluded that there can be no fixed
dose ratio between the products (13, 14). To date, most
published studies have focused on the gastrocnemius-
soleus complex and/or hamstrings (1, 7), and our data
provide a useful insight into practical dosing for other
proximal muscles of the lower limb.
Limitations of the current study include the retro-
spective design (i.e. no blinding) and lack of stan-
dardization (all children were treated as per standard
clinical practice, which is impacted by a variety of
social, personal and economic factors). Our analyses
were limited to the last cycle of OnaBoNT-A and first
cycle of AboBoNT-A. More studies are needed to pro-
spectively compare the various BoNT-A products over
longer durations of repeated treatment cycles. Some
of the patients treated with AboBoNT-A could not be
included in our analyses of treatment intervals because
they had not yet been reinjected at the time of cut-off.
The main driver of the switch was a change in health-
care policy and not related to the individual therapeutic
standpoint. It did not include any children with primary
or secondary non-response to OnaBoNT-A.
In summary, in this preliminary report of our
first experience of switching from OnaBoNT-A to
AboBoNT-A, therapeutic efficacy was sustained and
no safety concerns were identified. Most clinicians
prefer to maintain their patients on the same treatment
provided it is working, and switch only in cases of
non-response. Our experience of a mandated switch
for administrative reasons was positive, and should
be reassuring to clinicians involved in the long-term
management of children living with CP.
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