US scientists have begun editing genes inside patients to cure a disease that currently requires weekly treatment

For the first time, US scientists have attempted to edit the DNA of cells inside a patient in order to permanently cure a disease that currently requires weekly intravenous therapy.

Scientists at Sangamo Therapeutics are using genome editing to insert a corrective gene into a precise location in the DNA of liver cells.

Ultimately, the doctors aim to enable patients’ livers to produce a lifelong and stable supply of the enzyme iduronate-2-sulfatase (IDS), which sufferers of mucopolysaccharidosis type II (MPS II) – also known as Hunter syndrome – lack.

“For the first time, a patient has received a therapy intended to precisely edit the DNA of cells directly inside the body. We are at the start of a new frontier of genomic medicine,” said Dr. Sandy Macrae, CEO of Sangamo Therapeutics.

To insert the corrective gene the team didn’t use the popularised CRISPR  gene-editing technique, instead they used Sangamo’s zinc finger nuclease (ZFN) genome-editing technology.

In order to restrict editing solely to liver cells, the ZFNs and the corrective gene were delivered in a single intravenous infusion using AAV vectors that target the liver. The ZFNs entered the cells as inactive DNA instructions in a format designed only for liver cells to unlock.

Once “unlocked”, the ZFNs then identified, clung to and cut the DNA in a specific location within the albumin gene. Using the cells’ natural DNA repair processes, liver cells then inserted the corrective gene at the precise location.

“We cut your DNA, open it up, insert a gene, stitch it back up. Invisible mending,” said Macrae in an interview with Medical Xpress, “It becomes part of your DNA and is there for the rest of your life.”

Without IDS people with MPS II suffer debilitating buildup of toxic carbohydrates in cells throughout their body.

As a result, patients may suffer from frequent colds and ear infections, distorted facial features, hearing loss, heart problems, breathing trouble, skin and eye problems, bone and joint flaws, bowel issues and neurological problems.

Previously the treatment for this condition involved weekly infusions of enzyme replacement therapy (ERT), but for patients with MPS II within a day of receiving ERT, IDS can quickly return to near undetectable levels in the blood.

“Even with regular infusions of ERT, which has markedly improved functional health outcomes, patients endure progressive damage to heart, bones and lungs. Many patients with MPS II die of airway obstruction, upper respiratory infection or heart failure before they reach the age of 20,” said Paul Harmatz, M.D., a pediatric gastroenterologist and a principal investigator for the CHAMPIONS study at the UCSF Benioff Children’s Hospital Oakland, where the first subject in the study was treated.

Robot-assisted surgeries may be popular, but research suggests augmenting surgeons with robots isn’t worth the time or money

Surgeons removing patients’ kidneys in keyhole surgeries are better off working without robot assistance because using tech can result in longer operating times and increased costs.

That’s the conclusion put forward by researchers at the Stanford University School of Medicine who found that whether the operation was performed by human-only teams or with robot assistance had little effect on patient outcomes and lengths of hospital stay, but robot assistants contributed to longer operating times and increased costs, compared to traditional keyhole (laparoscopic) surgery.

“Although the laparoscopic procedure has been standard of care for a radical nephrectomy for many years, we saw an increase in the use of robotic-assisted approaches, and by 2015 these had surpassed the number of conventional laparoscopic procedures,” said Benjamin Chung, MD, associate professor of urology.

“We found that, although there was no statistical difference in outcome or length of hospital stay, the robotic-assisted surgeries cost more and had a higher probability of prolonged operative time.”

Although, surgeries that are less technically challenging, such as the removal of a whole kidney, may not benefit as significantly from a robot’s help, the researchers note that robots can help when tackling procedures that require increased dexterity.

Procedures such as the removal of the prostate or the removal of just a portion of the kidney, require a high degree of delicate manoeuvring and extensive internal suturing that render the robot’s assistance invaluable.

In cases where robot assistance was used unnecessarily, the researchers concluded there may be an expectation on the part of the hospital or the surgeons themselves to justify the large initial investment in purchasing the robot by using it for many types of procedures.

Patients themselves may also view robot-assisted surgery as more technologically advanced.

“There is a certain incentive to use very expensive equipment,” said Chung. “But it is also important to be cognisant as to how our health care dollars are being spent. Although robotic surgery has some advantages, are those advantages relevant enough in this type of case to justify an increase in cost?”

To gather their data the researchers analysed the approach of 416 hospitals across the US from 2003 to 2015.

They found that while in 2003 only 1.5% of patients needing laparoscopic surgery had it done via robot-assisted surgery, this had increased to 27% by 2015.

On average, the total hospital cost (including the cost of supplies, room and board, pharmaceuticals and operating room time) for the robot-assisted procedure exceeded that of the traditional laparoscopic procedures by about $2,700 per patient.

The researchers speculated that the increased cost may be due to longer times spent in the operating room as well as the increased cost of disposable instruments upon which surgical robots rely.