It did however continue to say that "any treatment that prolonged survival would not be seen as a burden by caregivers".
The subcommittee's reasoning, revealed today on Rare Disease Day, has been described as a human rights issue by outgoing New Zealand Organisation for Rare Disorders [NZORD] chief executive Dr Collette Bromhead.
She believed the decision was based on cost and not outcomes and said trials already showed significant improvement for sufferers of SMA I.
"It's not a cure but it's a revolutionary treatment.
"I put it to them [Pharmac] that this was actually a human rights issue and they were depriving these babies of the right to life," Bromhead said.
On Tuesday parents of babies with SMA I made an impassioned plea to Pharmac staff at an NZORD conference in Wellington for the funding and said: "Every day we wait our children get sicker."
Pharmac's subcommittee tasked with approving funding for drugs for rare disorders, recommended funding four medicines, declining five others and deferring the decision on Spinraza, the only treatment available for SMA, until the publication of two trials.
The estimated treatment retail cost of Spinraza, licenced by American drug company Biogen, is $1.4 million [US$750,000], though this would likely be discounted under a confidential rebate scheme, followed by four-monthly injections for the rest of the patient's life worth $135,000 per injection.
Biogen is offering an Early Access Programme for SMA I babies in New Zealand to bridge the time period between registration of the medicine and the funding of it by Pharmac.
Bromhead said there were systemic issues with Pharmac's funding model and NZORD was calling for an external review of the agency by UK agency the National Institute for Care and Excellence [NICE].
"The evidence of economic analysis crossing over with clinical assessment is a clear reason that Pharmac's model needs review after 25 years without external peer assessment."
Pharmac chief executive Sarah Fitt said its rare disorders subcommittee recommended the funding application for Spinraza be deferred at its November meeting and be reassessed after longer-term follow-up analyses was published from two clinical trials.
Fitt said Pharmac's expert clinical advisors provided objective clinical advice, taking into consideration before making their recommendations health need and benefits, costs and savings, and suitability.
It also considered three levels of impact to the person, their family, wider society and the broader health system.
"We take our responsibility to fund the right medicines for New Zealanders very seriously," Fitt said.
"We have a fixed budget, which means we must make careful and considered decisions about spending any available money on medicines to deliver the best health outcomes for New Zealand.
"We understand that patients, their families and whānau and clinicians want the newest medicines in the hope they will provide the best possible health result."
However, she said many new medicines were launched without clear evidence they work as pharmaceutical companies claim.
"These treatments can look promising, but we need to be absolutely sure they will deliver the benefits claimed, and that we spend public money wisely.
"If we fund a treatment with high uncertainty about its results, the reality is that it would take away funding from other more proven treatments."
