Hizentra is a prescription immunoglobulin therapy injected under the skin to treat two conditions: primary immunodeficiency (PI) in adults and children aged 2 and older, and chronic inflammatory demyelinating polyneuropathy (CIDP) in adults. It delivers concentrated antibodies from donated human plasma, either replacing what your immune system can’t make or modulating an overactive immune response attacking your own nerves.
Primary Immunodeficiency
Primary immunodeficiency refers to a group of more than 400 genetic disorders where the immune system doesn’t produce enough protective antibodies on its own. People with PI catch infections more frequently and have a harder time clearing them. Left untreated, even common respiratory or sinus infections can become serious or chronic.
Hizentra works here as straightforward replacement therapy. It supplies the antibodies your body is missing, giving your immune system the tools to fight off bacteria and viruses. In a clinical trial of pediatric patients using Hizentra, zero serious bacterial infections were recorded during the study’s efficacy period, which met the FDA’s benchmark for approval. The goal of ongoing treatment is to keep antibody levels high enough that serious infections stay rare.
For PI, Hizentra can be given anywhere from daily to every two weeks, depending on the dose your provider prescribes. That flexible schedule is one of its distinguishing features compared to IV immunoglobulin, which is typically given once a month in a clinic. Many PI patients use Hizentra at home on a weekly basis, fitting infusions around their normal routine.
Chronic Inflammatory Demyelinating Polyneuropathy
CIDP is a neurological condition where the immune system mistakenly attacks the protective coating around peripheral nerves, causing progressive weakness and numbness, usually in the legs and arms. It develops gradually over at least eight weeks, which distinguishes it from the more rapid onset of Guillain-Barré syndrome.
For CIDP, Hizentra serves as maintenance therapy. After an initial stabilization (often with IV immunoglobulin), patients transition to weekly subcutaneous infusions to prevent relapses. The PATH extension study, one of the largest trials for this use, found that only 10% of patients on the higher dose relapsed, compared to 48% on the lower dose. Among patients who did relapse after a dose reduction, 92% improved once the higher dose was restarted. These results helped establish Hizentra as a viable long-term option for keeping CIDP symptoms in check.
The CIDP approval is for adults only, unlike the PI indication which extends down to age 2.
How Hizentra Is Given
Hizentra is a 20% liquid immunoglobulin solution infused just beneath the skin using a small needle and portable pump. Common infusion sites include the abdomen, thighs, upper arms, and lateral hips. You can use up to eight infusion sites at the same time, as long as each site is at least two inches apart from the next.
For PI patients, the first infusion is limited to 15 mL per site, increasing to 25 mL per site once your body adjusts. CIDP patients start at 20 mL per site and can work up to 50 mL. A typical infusion session takes anywhere from one to two hours depending on the total volume and number of sites used. Most people learn to self-infuse at home after initial training with a nurse, which means far fewer trips to an infusion center.
Advantages Over IV Immunoglobulin
The biggest practical difference between Hizentra and traditional IV immunoglobulin (IVIG) is where and how often you receive it. IVIG requires a needle in a vein, usually in a clinic or hospital setting, once every three to four weeks. Hizentra goes under the skin and is designed for home use on a more frequent but smaller-dose schedule.
That frequent dosing creates a real clinical advantage: steadier antibody levels in your blood. After an IVIG infusion, antibody levels spike high and then gradually drop over the next month, creating a roughly 900 mg/dL swing between peak and trough. With weekly subcutaneous dosing, that swing shrinks to about 100 mg/dL. For many patients, those deep troughs before the next IVIG dose are when they feel most vulnerable to infections or symptom flares. A more stable level can mean more consistent protection and fewer “bad weeks.”
Subcutaneous infusion also tends to produce fewer systemic side effects like headaches, chills, and fatigue that are relatively common with IVIG. The trade-off is a higher rate of local reactions at the injection site, such as redness, swelling, or mild soreness. These local reactions are usually most noticeable in the first few weeks of treatment and tend to decrease over time.
Who May Not Be a Good Candidate
Hizentra is made from human plasma, so anyone with a known allergy to immunoglobulin products or who has had a severe reaction to blood-derived therapies should not use it. People with a rare condition called hyperprolinemia (a deficiency in breaking down the amino acid proline) need to avoid Hizentra specifically because it contains proline as a stabilizer.
Like all immunoglobulin products, Hizentra carries a boxed warning about the risk of blood clots. This risk is higher in people with existing cardiovascular risk factors: older age, prolonged immobility, history of blood clots, thickened blood, or conditions that make blood more likely to clot. If you fall into any of these categories, your provider will weigh the benefits against this risk and may monitor you more closely.
Hizentra is not an on-demand treatment. Both PI and CIDP require consistent, ongoing infusions to maintain their benefits. Missing doses or stopping abruptly can lead to a return of infections (for PI) or neurological relapses (for CIDP), so it works best for people who can commit to a regular infusion schedule at home.