What is and what is Natpar - Parathyroid Hormone used for?
Natpar is a hormone replacement drug to treat adults with hypoactive parathyroid glands, a condition known as hypoparathyroidism.
In patients with this condition, the parathyroid glands in the neck do not produce a sufficient amount of the parathyroid hormone that controls the level of calcium in the blood. As a result, patients have low calcium levels that can cause problems with bones, muscles, heart, kidneys and other parts of the body.
Natpar is used in addition to treatment with calcium supplements and vitamin D, when these treatments have not been sufficiently effective.
Because the number of patients suffering from hypoparathyroidism is low, the disease is considered "rare" and Natpar was qualified as an "orphan medicine" (a medicine used in rare diseases) on December 18, 2013.
The active ingredient in Natpar is the parathyroid hormone.
How is Natpar used - Parathyroid hormone?
Natpar is available as a powder and liquid to mix together to form a solution for injection. Natpar is injected subcutaneously into the thigh using the Natpar pen. The usual recommended starting dose is 50 micrograms once a day. The Natpar dose and that of the vitamin D and calcium supplements taken by the patient are then adjusted based on the patient's blood calcium levels. The maximum daily dose is 100 micrograms.
The patient can practice the Natpar injection alone after training. The medicine can only be obtained with a prescription and treatment must be monitored by a healthcare professional experienced in managing patients suffering from hypoparathyroidism. For more information, see the package leaflet.
How does Natpar - Parathyroid hormone work?
The active ingredient contained in Natpar, the parathyroid hormone, is a copy of the natural hormone produced by the parathyroid glands. Replaces the missing hormone in patients with hypoparathyroidism, helping them to restore calcium levels.
What benefit has Natpar shown during the studies?
Natpar has been shown to help control blood calcium levels in patients with hypoparathyroidism who are taking calcium and vitamin D supplements.
In a 24-week main study performed on 124 patients, 54.8% (46 of 84) of those who received Natpar achieved and maintained acceptable levels of calcium in the blood while reducing doses of calcium and vitamin supplements D at least 50%. The percentage of patients who took a placebo (a dummy treatment) and obtained the same result was 2.5% (1 patient out of 40).
What are the risks associated with Natpar - Parathyroid hormone?
The most common side effects of Natpar (which may affect more than 1 in 10 people) are levels of calcium in the blood that are too high or too low, which can lead to headache, diarrhea, vomiting, paraesthesia (unusual sensations like tingling and tingling), hypoesthesia (reduced sense of touch) and high levels of calcium in the urine. For the full list of all side effects reported with Natpar, see the package leaflet.
Natpar should not be used in patients who are undergoing or have undergone radiotherapy to their bones, are suffering from bone cancer or cancer that has spread to the bones and are more at risk of developing bone cancer called osteosarcoma. Furthermore, Natpar should not be used in patients who have unclear increases in the levels of an enzyme called alkaline bone phosphatase and in patients who have pseudo-hypoparathyroidism, a rare disease in which the body does not respond adequately to the parathyroid hormone it produces . For the full list of limitations, see the package leaflet.
Why has Natpar - Parathyroid Hormone been approved?
Natpar replaces the missing parathyroid hormone in patients with hypoparathyroidism. The main study showed that Natpar contributes to the control of calcium levels in the blood while reducing the need for calcium and vitamin D supplements. However, this study was short-lived and there was no evidence of improvements in the quality of patients' lives or reduction of long-term problems such as kidney failure. Therefore, Natpar should only be used in patients not adequately controlled with standard treatments alone and who have no other treatment options.
Regarding safety, the risk of calcium levels becoming too high or too low is considered important: more data are needed to better understand the consequences of major fluctuations in the level of calcium in the blood after taking the medicine once a day .
Since the data available is limited, Natpar has obtained a "conditional approval". This means that further information on the medicine, which the company is required to provide, will be available in the future. Every year the European Medicines Agency will review the new information available and this summary will be updated accordingly.
What information is still awaited for Natpar?
Because Natpar has been given a conditional approval, the company that markets Natpar will conduct an additional study to confirm the benefits and risks of the medicine and the adequacy of once-a-day administration
What measures are being taken to ensure the safe and effective use of Natpar - Parathyroid Hormone?
The company that markets Natpar will set up a registry and collect long-term data on Natpar-treated patients, including the effects on the bones, kidneys and quality of life of the patients themselves.
Recommendations and precautions to be followed by healthcare professionals and patients for Natpar to be used safely and effectively have also been included in the summary of product characteristics and the package leaflet.
More information on Natpar - Parathyroid hormone
The full EPAR for Natpar can be found on the Agency's website :: ema.europa.eu/Find medicine / Human medicines / European public assessment reports. For more information on Natpar therapy, read the package leaflet (also part of the EPAR) or contact your doctor or pharmacist.
The summary of the opinion of the Committee for Orphan Medicinal Products related to Natpar is available on the Agency's website: ema.europa.eu/Find medicine / Human medicines / Rare disease designation.
