Leukocyte adhesion deficiency type 1 (LAD-1) is a rare inherited condition with a faulty ITGB2 gene that you are born with. It weakens your immune system and keeps white blood cells from fighting infections. The ITGB2 gene helps white blood cells stick to blood vessel walls and move into tissues to fight infections. When it does not work properly, the immune system does not work the way it should. Severe LAD-1 leads to frequent and ongoing infections that can be life-threatening, sometimes very early in life.
In some cases, LAD-I can be cured with a stem cell transplant using healthy cells from a donor. However, these transplants can be risky, especially if there is no closely matched donor, such as a sibling.
A new treatment option is a type of gene therapy that uses the patient’s own cells. In March 2026, the FDA approved Kresladi (marnetegragene autotemcel), the first gene therapy to treat children who have severe LAD-1 with a faulty ITGB2 gene inherited from both parents. It offers another treatment option, especially when there is no closely matched sibling donor for a stem cell transplant.
Continue reading to learn more about how Kresladi works, possible benefits, and what to expect with use.
Kresladi Side Effects and Interactions: What to Expect and How to Manage Them
How Does Kresladi Work for LAD-1?
Kresladi is a type of personalized gene therapy for one-time use. It uses your child’s own stem cells, which are collected from their blood. It helps change the faulty gene into a working one. The “corrected” stem cells are then given back to your child through one of their veins. This helps your child make new healthy white blood cells with higher levels of two specific proteins, CD18 and CD11a. These proteins help white blood cells get to and stay in parts of your body where a bacterial, viral, or fungal infection is growing. This helps your child’s immune system fight these infections in a better way.
How Was Kresladi Studied for LAD-1?
Kresladi was studied in a very small clinical trial in children with severe LAD-1. Severe disease was generally defined as having very low CD18 levels (less than 2%). Some children with slightly higher CD18 levels were also included if they had very low levels of related proteins (CD11a or CD11b), proof of a faulty ITGB2 gene, and a personal or family history of LAD-1.
The trial included nine children, and there was no comparison group. All children used Kresladi and were followed for about 4.2 years (ranging from 3.6 to 5.7 years) after treatment.
Below are the characteristics of the children at the beginning of the trial:
- Their age ranged from about 10 months to almost 10 years, with a median age of 3 1/2 years.
- 56% were female, while the rest were male (44%).
- Six children were White (67%), two were Asian (22%), and race was not reported for one child (11%).
- None of the children had received a stem cell transplant in the past.
- All nine children had CD11a levels below 2%.
- Seven of the nine children had CD18 levels below 2%.
The goal of the trial was to see if CD18 or CD11a levels increased after Kresladi treatment. Levels were measured at 12 months and two years after treatment. CD18 and CD11a levels are considered surrogate markers for LAD-1. Because the faulty gene in children with LAD-1 affects proteins that are hard to measure directly, researchers measured CD18 and CD11a levels instead. Higher levels are linked to less severe LAD-1 disease and suggest better immune function and an improved ability to fight infections.
The trial also monitored to see how many children needed a stem cell transplant.
What Benefits Were Seen?
Both CD11a and CD18 levels increased after receiving Kresladi. CD18 levels rose to values linked to mild or moderate LAD-1 instead of severe disease. See the table below for specific results from the clinical trial.
| 12 months after Kresladi infusion | 24 months after Kresladi infusion | |
|---|---|---|
| Median CD18 levels* | 54% (ranged from 20% to 87%) | 50% (ranged from 16% to 82%) |
| Median CD11a levels | 45% (ranged from 18% to 75%) | 39% (ranged from 17% to 65%) |
*Evaluated for seven of the nine children because two of them had levels less than 2% at the beginning of the study.
Also, none of the children in the study required a stem cell transplant during the follow-up period. Together with the increase in CD18 and CD11a, these results suggest that Kresladi may be an option to treat severe LAD-1 in certain children.
Keep in mind your child’s results may be different from those seen in this trial.
The FDA approved Kresladi through a pathway called accelerated approval. This pathway allows earlier access to medicines for serious conditions when early study results show that a treatment improves an important surrogate marker. In this case, the surrogate markers were CD18 and CD11a levels. More studies are needed to see if Kresladi can lead to meaningful improvement for people with LAD-1.
How Is Kresladi Given?
Kresladi is a personalized gene therapy that is given by a health care provider in a hospital or clinic. The actual process of receiving Kresladi involves multiple steps and takes time to complete.
First, a health care provider must collect your child’s stem cells and send them to a lab. Before stem cells are collected, your child may need to stop taking certain medicines and start others. Your child may need more than one collection to get enough cells for your dose. It is recommended to collect enough cells for the dose, along with extra cells as backup in case there are problems. Once these cells are collected, it will take time for the lab to prepare the corrected cells.
When your corrected cells are ready, your child will need to receive “conditioning” treatment. This clears most, if not all, of the bone marrow cells from your body. The medicines used for conditioning have many side effects, and your child may need to take other medicines to help prevent or treat these side effects. Since conditioning removes your body’s ability to fight off infections and increases your risk for bleeding, your child will need to stay in the hospital during and after this treatment.
Kresladi, which is made of your own corrected cells, is usually given about 24-48 hours after conditioning. These cells are then infused into your vein (IV). Your body will use Kresladi to rebuild your bone marrow, a process called engraftment, which typically takes up to six weeks. Since your child will still be at high risk for infection and bleeding while waiting for engraftment, your child may need to stay in the hospital for some, if not all, of this time.
Will Kresladi Work for Everyone?
The goal after a Kresladi infusion is for your child’s body to make the right amount of healthy white blood cells so they can fight infections. However, there is no guarantee that Kresladi will work for everyone. Your child’s health care provider will monitor white blood cell levels after the infusion to monitor treatment.
Other than improved white blood cell levels and function, there are other possible outcomes after receiving Kresladi.
- Your child’s body may not make enough white blood cells. This is known as primary engraftment failure.
- Your child’s body may make enough white blood cells at first, but levels decrease over time. This is known as secondary engraftment failure.
To prepare for these possibilities, extra stem cells are collected when preparing your child for their Kresladi infusion. These cells are frozen. This keeps them safe so they can still be used in case of any type of engraftment failure or if there is a problem when preparing your corrected cells.
Are There Any Restrictions After Getting Kresladi?
There are two restrictions after receiving Kresladi to be aware of. One involves donating blood, organs, tissues, or cells. The other involves receiving a blood transfusion.
Anyone who receives Kresladi should never donate blood, organs, tissues, or cells. This is not because of any known infection risk, but because there is no data available to know if it is safe to donate or how the engineered change could affect whoever receives your donation. Talk to your child’s health care provider if you have concerns.
If your child needs a blood transfusion within the first three months after receiving Kresladi, be sure the health care team caring for your child knows that they received it. Blood products may need a special treatment, known as irradiation, before they can be given to you. Irradiation is used to reduce the risk of serious complications after receiving the transfusion.