Listing of Pharmaceutical Benefits (NHL) - Schedule 4 part 1

Symptomatic Type I, II or IIIa spinal muscular atrophy (SMA)

Initial treatment

The condition must have genetic confirmation of 5q homozygous deletion of the survival motor neuron 1 (SMN1) gene; or

The condition must have genetic confirmation of deletion of one copy of the SMN1 gene in addition to a pathogenic/likely pathogenic variant in the remaining single copy of the SMN1 gene; AND

Patient must have experienced at least two of the defined signs and symptoms of SMA type I, II or IIIa prior to 3 years of age; AND

The treatment must be given concomitantly with best supportive care for this condition; AND

The treatment must not be in combination with PBS-subsidised treatment with nusinersen for this condition; AND

The treatment must be ceased when invasive permanent assisted ventilation is required in the absence of a potentially reversible cause while being treated with this drug; AND

Must be treated by a specialist medical practitioner experienced in the diagnosis and management of SMA associated with a neuromuscular clinic, or in consultation with a specialist medical practitioner experienced in the diagnosis and management of SMA associated with a neuromuscular clinic; AND

Patient must not have received PBS-subsidised gene therapy; AND

Patient must be 18 years of age or under.

Defined signs and symptoms of type I SMA are:

i) Onset before 6 months of age; and

ii) Failure to meet or regression in ability to perform age-appropriate motor milestones; or

iii) Proximal weakness; or

iv) Hypotonia; or

v) Absence of deep tendon reflexes; or

vi) Failure to gain weight appropriate for age; or

vii) Any active chronic neurogenic changes; or

viii) A compound muscle action potential below normative values for an age-matched child.

Defined signs and symptoms of type II SMA are:

i) Onset between 6 and 18 months; and

ii) Failure to meet or regression in ability to perform age-appropriate motor milestones; or

iii) Proximal weakness; or

iv) Weakness in trunk righting/derotation; or

v) Hypotonia; or

vi) Absence of deep tendon reflexes; or

vii) Failure to gain weight appropriate for age; or

viii) Any active chronic neurogenic changes; or

ix) A compound muscle action potential below normative values for an age-matched child.

Defined signs and symptoms of type IIIa SMA are:

i) Onset between 18 months and 3 years of age; and

ii) Failure to meet or regression in ability to perform age-appropriate motor milestones; or

iii) Proximal weakness; or

iv) Hypotonia; or

v) Absence of deep tendon reflexes; or

vi) Failure to gain weight appropriate for age; or

vii) Any active chronic neurogenic changes; or

viii) A compound muscle action potential below normative values for an age-matched child.

Invasive permanent assisted ventilation means ventilation via tracheostomy tube for greater than or equal to 16 hours per day.

Application for authorisation of initial treatment must be in writing and must include:

(a) details of the proposed prescription; and

(b) a completed Spinal muscular atrophy PBS Authority Application Form which includes the following:

(i) specification of SMA type (I, II or IIIa); and

(ii) sign(s) and symptom(s) that the patient has experienced; and

(iii) patient's age at the onset of sign(s) and symptom(s).

The approved Product Information recommended dosing is as follows:

(i) 16 days to less than 2 months of age: 0.15 mg/kg

(ii) 2 months to less than 2 years of age: 0.20 mg/kg

(iii) 2 years of age and older weighing less than 20 kg: 0.25 mg/kg

(iv) 2 years of age and older weighing 20 kg or more: 5 mg

In this authority application, state which of (i) to (iv) above applies to the patient. Based on (i) to (iv), prescribe up to:

1 unit where (i) applies;

2 units where (ii) applies;

3 units where (iii) applies;

3 units where (iv) applies.