Medicinal cannabis oil has been returned to the boy with a severe case of epilepsy after it was confiscated from his mother at customs.
Billy Caldwell , 12, was given the oil after doctors made it clear it was a "medical emergency", Sajid Javid said.
Billy's mother, Charlotte Caldwell, from County Tyrone, said they had "achieved the impossible", but called for the oil to be freely available.
Billy started using cannabis oil in 2016 to control his seizures.
Cannabis oil, which contains a substance called Tetrahydrocannabinol (THC), is illegal in England but available in other places.
Billy's most recent stash - which Ms Caldwell had tried to bring to the UK from Canada - was confiscated at Heathrow Airport on June 12, and the boy was admitted to hospital before Mr Javid said he would be returned.
The oil arrived at Chelsea and Westminster Hospital, where Billy is hospitalized, on the afternoon of June 16th. He was given a 20-day special license and is not allowed to take it home.
A Home Office spokeswoman said it was an “exceptional licence” for a “short-term emergency”, and would need to be reviewed.
'Completely destroyed'
Ms Caldwell said: “I truly believe that somewhere in the Home Office there is someone with a heart, and I truly believe that Billy has touched that deeply.”
But he said [Billy's] "little body and mind were completely destroyed."
“No other family should have to go through this ordeal, traveling halfway around the world to get medicine that should be freely available,” he said.
“My experience leaves me in no doubt that the Home Office can no longer play a role in the administration of medicines for sick children in our country.
“Children are dying, and it must be stopped immediately.”
Mr Javid said he issued a license to allow Billy to be treated with cannabis oil after several discussions with the child's medical team.
“It's a very complicated situation, but our immediate priority is to make sure Billy receives the most effective treatment possible in a safe way,” he said.
“My decision is based on the advice of expert clinicians who have made it clear that this is a medical emergency.
“The security minister met with the family on Monday, and has since worked to reach an urgent solution.”
Barbara Zieniewicz, co-founder of the advocacy group Families4Access, who went to Canada with Billy and Ms. Caldwell, called Mr. Javid's decision “triumphant.”
“I firmly believe that this is the first push – from here, it's a chain reaction. This, to me, means there is hope, not just for Billy, but for all the families who need it.”
Billy, from Castlederg, began treatment in 2016 in America, where medical marijuana is legal.
Ms. Caldwell says Billy's seizures decrease dramatically when he takes the oil.
In 2017, he was prescribed the medicine by the NHS (England's national health service). But, in May this year, her GP was told he could no longer prescribe it.
At the time the Department of Health in Northern Ireland said that cannabis had not yet been approved as a medicine in the UK.
In June, Ms Caldwell tried to bring a six-month supply of the oil - to treat up to 100 seizures a day - to England from Toronto, but the substance was confiscated by officers at Heathrow Airport.
The boy's family said he was taken to hospital when the attacks intensified in the following days.
The family's MP, Órfhlaith Begley, said the Home Office decision was "life-saving", adding: "I will continue to challenge the Home Office and the health authorities to ensure he has long-term access to his medicines, so that the trauma he has suffered in recent weeks does not happen again."
'Not simple'
Dr Amir Englund, who studies cannabis at the Psychiatric Institute of King's College London, said: “Clearly, there is evidence that Billy's medicines work for him where others have failed.
“The government's job is to protect its citizens from harm by regulating medicines, so that the medicines doctors prescribe are safe and effective.
“However, there are cases where these measures become counterproductive and harmful. This is an example of that, and the Home Office should allow an exemption so that no further harm is done to them."
Meanwhile, clinical lecturer in psychiatry at University College London, Dr Michael Bloomfield, said that on the one hand “the current laws are too strict”, but added that the medical marijuana problem is “far from it”. How simple."
“Any 'medical marijuana' requires a scientific evidence base, in the form of medical trials etc., which is lacking for many disorders, and has become, for many jurisdictions, a potential way to decriminalize cannabis in a roundabout way,” he said. said.
Does Cannabis Have Medicinal Benefits?
CBD and Tetrahydrocannabinol (THC) are two types of cannabinoids found naturally in the resin of Marijuana plants.
A cannabis-based drug, Sativex, has been approved in England to treat multiple sclerosis. Contains THC and CBD.
Doctors could, in theory, prescribe it for other things outside of licensing, but at their own risk.
Multiple sclerosis patients who have been prescribed Sativex and who buy it for other people are subject to criminal prosecution.
Another authorized treatment is Nabilone. It contains an artificial version of THC and can be given to cancer patients to help relieve nausea during chemotherapy.