Takeda’s Rare Disease Drug Natpara Won’t Be Available for Another Year

Rare Daily Staff

At the end of March, Takeda Pharmaceuticals sent a letter to the Hypoparathyroidism Association and patient community at large to let them know that its parathyroid hormone Natpara would not be available to them until April 2022.

The delay affects about 2,400 people with hypoparathyroidism including about 400 people who receive the drug through the company’s special use program because they are at high risk for life-threatening complications.

Hypoparathyroidism is a rare condition in which the parathyroid glands fail to produce sufficient amounts of parathyroid hormone or the parathyroid hormone produced lacks biologic activity. Parathyroid hormone plays a role in regulating the levels of calcium and phosphorus in the blood and in determining bone growth and bone cell activity. Due to a deficiency of parathyroid hormone, individuals may exhibit abnormally low levels of calcium in the blood (hypocalcemia) and high levels of phosphorus (hyperphosphatemia). Hypocalcemia can cause symptoms including weakness, muscle cramps, excessive nervousness, headaches, and/or uncontrollable twitching and cramping spasms of certain muscles such as those of the hands, feet, arms, legs, and/or face. Numbness and tingling around the mouth and in the fingers and toes can also occur.

Takeda said that the supply issue is separate from Natpara’s recall in September 2019 due to manufacturing issues that involved rubber particulates in the Natpara cartridge delivery system.

The company anticipates that the supply interruption, which the company said involves the 100-mcg dosage, will start immediately, but it will not affect patients enrolled in the special use program at this time.

“While we have made progress on the original issue that led to the U.S. recall, which was the issue of rubber particulates originating from the rubber septum of the NATPARA cartridge, we have not yet reached a resolution,” the company said.

The manufacturing delay that’s currently affecting NATPARA 100-mcg within the special use program has further impacted its timelines, and at this time we do not expect a return to market before March 31, 2022, the company added. “Patients who are enrolled in the SUP program continue to have access to therapy, and we will keep the

community informed of relevant updates as we progress.”