HSAN Type IV Clinical Trial
Official title:
A Phase II, Randomized, Double Blind, Cross-over, Placebo-controlled Study on Norepinephrine Replenishment Therapy Using L-DOPS in Congenital Insensitivity to Pain With Anhidrosis Patients
The aim of this study is to increase norepinephrine levels in a population of young adults
where NE levels are very low or undetectable. In order to achieve this, the optimal dose
will be determined in a titration step. In the titration step, different doses of L-DOPS
will be tested in order to find the optimal and safest dose suitable for each individual
enrolled in the study. Because L-DOPS has never been used in the US in children or young
adults, with this titration step investigators will also determine the safest dose for this
population.
Currently, L-DOPS is being used in our center to treat othostatic hypotension in autonomic
failure. The titration step for this study starts with the dose of 100 mg and increases in
an escalating manner up to a maximum of 600 mg a day (see investigational brochure
attached).
L-DOPS has been developed in capsules for oral used and all the previous safety data has
been performed using this route. Oral route is the one that will used during study.
Carbidopa is well tolerated, safe in children and it has been used in this population in the
US without severe adverse effects.
CIPA patient do have very low or undetectable levels of norepinephrine in plasma and also
have significant cognitive and behavioral problems. The aim of this project is to increase
NE levels in brain and evaluate if this increase improve cognitive cognition or behavior.
Both drugs from the study have never been used in CIPA patients before, it is therefore very
important to evaluate safety and tolerability of L-DOPS and carbidopa in this population.
Even if NE levels are very low in plasma of CIPA subjects, it is not know if NE levels are
also low in central nervous system. It is very likely that this is also the case, however,
levels of NE in brain will be checked in one CIPA subject as a prof of concept.
Study overview: Patients with CIPA will be screened and enrolled (visit 1) into part 1 of
the pilot trial. Safety parameters including, adverse events, blood chemistries for renal
and liver function testing, 12 lead electrocardiogram, temperature, weight and blood
pressure (supine, seated and standing), non-verbal intelligence and behavior test, 24 hour
urinary catecholamine excretion and plasma dopamine levels will be measured at baseline.
The patients will enter an open-label dose titration phase (visit 2a,b,c,d,e,f) during which
adverse events will be continuously monitored. After reaching a dose the 100 mg/day dose,
patients will be questioned about adverse events and have their blood pressure (supine,
sitting and standing) measured. If no adverse events or abnormalities are detected patients
will continue the dose titration. Safety assessments will be repeated and safety bloods
obtained when the patient reaches the maximum tolerated dose.
After completion of the dose titration, patients who are able to tolerate L-DOPS will enter
into a second open-label dose titration phase where carbidopa will be titrated (visit
3a,b,c,d,e,f). A period of two weeks will be allowed to washout the L-DOPS before starting
with the carbidopa titration.
Carbidopa have been previously used in clinical studies in children, young adults and adults
in our group and no adverse effects have been reported. There is no reason to think that
carbidopa may be unsafe in CIPA patients, however, the aim of these titration step is to
check safety and tolerability of the drug in this population. Subjects will receive a dose
of 100 mg/day and will be questioned about adverse events and have their blood pressure
(supine, sitting and standing) measured. If no adverse events or abnormalities are detected
patients will continue the dose titration. In the following steps, the doses of carbidopa
will be increased 100 mg daily up to a total of 600 mg/day. Safety assessments will be
repeated and safety bloods obtained when the patient reaches a total daily dose of 600
mg/day.
In the final phase of the titration, both L-DOPS and carbidopa will be administered (visit
4a,b,c,d,e). The starting dose of L-DOPS will be the maximum tolerated dose during the
L-DOPS titration step. The dose of carbidopa that will be administered with L-DOPS will be
the maximum tolerated dose. L-DOPS will be increase in 100 mg/day up to 600 mg/day, unless
any adverse affect is observed and then the titration will stop at that dose of L-DOPS. The
dose of carbidopa will be the maximum tolerated during the titration and will not be
increased.
After reaching the maximum L-DOPS/carbidopa tolerated dose, patients will be questioned
about adverse events with the medication and have their blood pressure (supine, sitting and
standing) measured. After the safety evaluation if no adverse events or abnormalities are
observed in the patients will continue with the study. A period of two weeks will be allowed
to washout the L-DOPS/carbidopa before starting with placebo-controlled double-blind cross
over phase.
Patients who successfully complete titration will proceed to the randomized placebo control
phase. Before proceeding to this part, researcher will review of safety data from the
titration. Patients will be randomized in a double-blind fashion, to receive either
L-DOPS/carbidopa or matching placebo. Patients will take the medication for 4 weeks.
After 4 weeks, 24 urinary catecholamine excretion, plasma dopamine levels, behavior scores,
safety parameters and adverse events will be measured (visit 5), before patients are crossed
over (visit 6). A similar dose withdrawal scheme will be implemented to prevent adverse
effects from acute withdrawal. Patients will be followed for a further 4-weeks. After
completion of the cross over period, patients will undergo final evaluation (visit 7) during
which safety and efficacy measures will be repeated. To conclude the study, 2 weeks after
completing the pilot-trial, patients will receive a follow up phone call to monitor any
adverse events.
All necessary safety information will be reported to the FDA in accordance with 312.32 IND
safety reports as outlined in Title 21 Food and Drugs.
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Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment