Rare but Real: Raising Awareness for Hypoparathyroidism this Rare Disease Day

Each year on the last day of February, people living with rare diseases—along with caregivers, healthcare professionals, advocacy groups, and others—come together to drive meaningful change and push for equitable care on Rare Disease Day.

With nearly 300 million people worldwide affected by rare diseases, this global movement amplifies the voices of those living with diseases that often go unrecognized. The European Organization for Rare Diseases (EURORDIS) founded Rare Disease Day in 2008, choosing February 29—a rare calendar date—to symbolize the nature of these diseases. Since then, EURORDIS, in collaboration with over 65 global organizations, has worked tirelessly to raise awareness, foster community, and advocate for better resources.

For the estimated 77,000 to 115,000 people in the U.S. living with hypoparathyroidism (hypopara), Rare Disease Day is an opportunity to shine a light on this often-misunderstood disease and the need for improved awareness, diagnosis, and treatment—including an available FDA-approved treatment option that directly addresses the disease's root cause.

What is Hypopara?

Hypopara is a rare endocrine disease caused by insufficient levels of parathyroid hormone (PTH)—a key hormone that regulates calcium and phosphate levels in the bone, kidney, and intestine. Without enough PTH, the body struggles to maintain normal calcium balance, leading to symptoms like muscle cramps, tingling, brain fog, fatigue, and even seizures.

Approximately 75% of chronic hypopara cases occur due to accidental damage to or removal of the parathyroid glands during neck surgery, such as a thyroidectomy, while other causes stem from genetic and/or autoimmune conditions, or secondary or unknown causes.

Despite knowledge of what causes hypopara, it remains both underdiagnosed and undertreated, largely due to a lack of awareness among healthcare providers—and, until recently, lack of reliably available PTH-based therapies.

Challenges of Diagnosis and Treatment

Diagnosing hypopara can be challenging because its symptoms often overlap with other common medical conditions. For example, postsurgical patients may not show symptoms immediately, and the disease may only be detected during routine checkups or when healthcare providers investigate concerns like fatigue or muscle aches. Since these symptoms are nonspecific, hypopara can often be overlooked.

Historically, treatment options have been limited. For years, patients have been prescribed conventional therapy, which consists of active vitamin D and calcium, to manage some symptoms. However, conventional therapy does not address the missing PTH and may result in a high pill burden for patients.

FDA-Approved Treatment

YORVIPATH^® is the first and only FDA-approved treatment for hypopara in adults in the U.S. YORVIPATH is a prescription medicine used to treat adults with low parathyroid hormone (PTH). This ready-to-use, once-daily injection provides continuous exposure to active PTH throughout the 24-hour dosing period.

The safety and effectiveness of YORVIPATH have not been established in individuals recently diagnosed with hypoparathyroidism following surgery or those with low calcium levels at the start of treatment. Additionally, its use is not recommended in children or young adults with developing bones. YORVIPATH may lead to high or low calcium levels in the blood or possible bone cancer. For more detailed safety information, please refer to the end of this article.

Unlike conventional therapy that relies on high doses of calcium and active vitamin D, YORVIPATH directly addresses the root cause of the disease. The goal of treatment with YORVIPATH is to maintain serum calcium levels in the normal range without the need for active vitamin D or therapeutic calcium doses. However, patients can continue taking calcium supplements as needed to meet their daily dietary requirements.

Community and Advocacy

To assist patients in starting and continuing treatment, the Ascendis Signature Access Program^® (A•S•A•P) offers patient support with treatment initiation, insurance issues, and ongoing adherence. This program provides services to eligible patients prescribed YORVIPATH for its approved indication.

For those living with hypopara, connecting with advocacy organizations and patient support groups can offer community as well as essential resources and education. Organizations like the HypoPARAthyroidism Association help build this community and are dedicated to empowering patients through education, advocacy, and support.

This Rare Disease Day, raising awareness about hypopara is crucial to improving early diagnosis, expanding treatment awareness, and enhancing support for those affected. By fostering greater understanding and advocacy, we can drive meaningful change and improve lives.

IMPORTANT SAFETY INFORMATION AND USE

What is the most important information I should know about YORVIPATH^®?

YORVIPATH may cause serious side effects, including:

• High levels of calcium in the blood (hypercalcemia). YORVIPATH can cause some people to have higher blood calcium levels than normal. Your healthcare provider should check your blood calcium before you start and during your treatment with YORVIPATH. Tell your healthcare provider right away if you have nausea, vomiting, dizziness, feeling thirsty, confusion, muscle weakness, or irregular heartbeat. Hypercalcemia is more likely to occur within the first 3 months of starting YORVIPATH, but it may occur at any time.

• Low levels of calcium in the blood (hypocalcemia). People who stop using, miss, or change a dose of YORVIPATH may have an increased risk of low blood calcium levels, but hypocalcemia may occur at any time. Tell your healthcare provider right away if you have tingling in your fingertips, toes, lips or tongue, muscle spasms or cramps, oral numbness, depression, have problems thinking or remembering, abnormal heart rhythms, or seizures.

• Possible bone cancer (osteosarcoma). Tell your healthcare provider right away if you have pain in any areas of your body that does not go away or any new or unusual lumps or swelling under your skin that is tender to touch. These are some of the signs and symptoms of osteosarcoma and your healthcare provider may need to do further tests.

Who should not take YORVIPATH?

Do not use YORVIPATH if you are allergic to palopegteriparatide or any of the other ingredients in YORVIPATH.

What should I tell my healthcare provider before taking YORVIPATH?

Before using YORVIPATH, tell your healthcare provider about all of your medical conditions, including if you:

• are at higher risk of a type of bone cancer called osteosarcoma. This is especially important:
  • if you have a bone disease that increases your risk of developing osteosarcoma (including if you have Paget's disease).
  • if a blood test shows that you have unexplained increases in bone alkaline phosphatase.
  • if you have cancer of the bones or other cancer that has spread to your bones.
  • if you are having or have had radiation therapy to the skeleton.
  • if you are affected with a condition that runs in your family that can increase your chance of getting cancer in your bones.

• take medicines that contain digoxin, are used to treat osteoporosis, or can affect calcium levels in your blood.

• are pregnant or plan to become pregnant. It is not known if YORVIPATH will harm your unborn baby. Tell your healthcare provider if you become pregnant during treatment with YORVIPATH.

• are breastfeeding or plan to breastfeed. It is not known if YORVIPATH passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby during treatment with YORVIPATH.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. YORVIPATH and other medicines may affect each other causing side effects.

What are the possible side effects of YORVIPATH?

YORVIPATH may cause serious side effects:

• Allergic (hypersensitivity) reaction, including anaphylaxis. Stop taking YORVIPATH and tell your healthcare provider or get emergency medical help right away if you have swelling of your face, lips, mouth, or tongue, breathing problems, fainting, dizziness, feeling lightheaded (low blood pressure), fast heartbeat, itching, rash, or hives.

• Decrease in blood pressure when you change positions (orthostatic hypotension). Some people may feel dizzy, get a fast heartbeat, or feel light-headed right after injecting YORVIPATH. For the first few doses, give your injection of YORVIPATH in a place where you can sit or lie down right away if you get these symptoms. If your symptoms get worse or do not go away, contact your healthcare provider before you continue using YORVIPATH.

• Digoxin toxicity if you are using digoxin and YORVIPATH at the same time. Tell your healthcare provider if you experience irregular heart rhythm, heart palpitations, confusion, loss of appetite, nausea, vomiting, diarrhea, or vision problems.

The most common side effects of YORVIPATH include injection site reactions, vasodilatory signs or symptoms such as a drop in blood pressure or lightheadedness when standing up, headache, diarrhea, back pain, high calcium levels, and sore throat.

These are not all of the possible side effects of YORVIPATH. Call your doctor for medical advice about side effects. You are encouraged to report side effects to FDA?www.fda.gov/medwatch. You may also report side effects to Ascendis Pharma at 1-844-442-7236.

What is YORVIPATH used for?

YORVIPATH is a prescription medicine used to treat adults with low parathyroid hormone (PTH) (hypoparathyroidism).

• It is not known if YORVIPATH is safe and effective in people who have been recently diagnosed with hypoparathyroidism after surgery, or if it is started in people with low levels of calcium in the blood.

• It is not known if YORVIPATH is safe and effective in children.

• YORVIPATH should not be used in children and young adults whose bones are still growing.

Please click here for full Prescribing Information for YORVIPATH and Medication Guide.

For more information about YORVIPATH, please visit www.yorvipath.com or call +1 844-442-7236.