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

Symptomatic type IIIB/IIIC spinal muscular atrophy (SMA)

Initial PBS-subsidised treatment in a child

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 not be receiving invasive permanent assisted ventilation in the absence of a potentially reversible cause while being treated with this drug; AND

Patient must be of an age that is prior to their 19th birthday at the time of this authority application; AND

Patient must have SMA type III where the onset of signs/symptoms of SMA first occurred after their 3rd birthday, but before their 19th birthday (SMA type IIIB/IIIC); AND

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

Patient must be undergoing initial PBS-subsidised treatment for untreated disease - prescribe up to 3 repeat prescriptions to enable dosing occurring at days: 0 (original prescription), 14 (repeat 1), 28 (repeat 2), 63 (repeat 3) (i.e. the loading doses); or

Patient must be undergoing initial PBS-subsidised treatment, but the patient has initiated treatment via non-PBS supply (e.g. clinical trial, sponsor compassionate access) - prescribe zero repeat prescriptions where loading doses are complete; AND

Patient must be undergoing concomitant treatment with best supportive care, but this benefit is the sole PBS-subsidised disease modifying treatment.

The authority application must be made in writing and must include:

(1) details of the proposed prescription; and

(2) a completed authority application form relevant to the indication and treatment phase (the latest version is located on the website specified in the Administrative Advice).

Signs and symptoms of spinal muscular atrophy in the context of this PBS restriction are:

(i) Failure to meet or regression in ability to perform age-appropriate motor milestones,

(ii) Proximal weakness,

(iii) Hypotonia,

(iv) Absence of deep tendon reflexes,

(v) Any active denervation or chronic neurogenic changes found on electromyography,

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

In this authority application, confirm:

(1) the patient's medical history is consistent with a diagnosis of type IIIB/IIIC spinal muscular atrophy,

(2) which of the above (i to vi) (at least 1) were present after their 3^rd birthday, but before their 19^th birthday,

(3) the age of the patient (rounded to the nearest year) when the first sign/symptom was observed.

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

Symptomatic type IIIB/IIIC spinal muscular atrophy (SMA)

Changing the prescribed therapy

Patient must be undergoing a change in prescribed SMA drug to this drug - the drug treatment being replaced was a PBS benefit initiated prior to the patient's 19th birthday for SMA type IIIB/IIIC; AND

Must be treated by a specialist medical practitioner experienced in the diagnosis/management of SMA; or

Must be treated by a medical practitioner who has been directed to prescribe this benefit by a specialist medical practitioner experienced in the diagnosis/management of SMA; AND

Patient must be undergoing concomitant treatment with best supportive care, but this benefit is the sole PBS-subsidised disease modifying treatment; AND

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

Patient must not be receiving invasive permanent assisted ventilation in the absence of a potentially reversible cause while being treated with this drug.

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

The prescriber has given consideration to whether a 'wash out' period is recommended or not prior to changing the prescribed therapy.