When Seshagiri Buddana learned of a powerful new cystic fibrosis drug that was transforming lives in the United States and Europe, he was filled with hope that it could help his son, Hemanth, who had spent much of his childhood in a hospital bed. But the family couldn't get the drug because they live in India.

The drug's maker, Vertex Pharmaceuticals, a large biotech company based in Boston, is not making it available in India or virtually anywhere in the developing world. The company is not trying to sell it, or allowing a local company to make it. Vertex is blocking potential generic competitors by seeking patents in numerous countries.

Hemanth died in December, a day before his 9th birthday and 18 months after he would have been eligible to get the drug, called Trikafta, had he lived in the U.S.

Throughout much of Asia, Africa and Latin America, families like Hemanth's are watching Trikafta transform the lives of tens of thousands of cystic fibrosis patients in wealthy nations but say they are blocked by the company at every turn in their efforts to get the drug themselves.

Trikafta, taken as three tablets a day, is the most powerful and widely used of Vertex's four cystic fibrosis medications. With a list price of more than $322,000 annually in the United States, it is expected to cost millions of dollars over the course of a patient's lifetime. An analysis led by researchers in Britain found that a year's supply of the drug could be manufactured at an estimated cost of just $5,700.

Vertex has reported more than $15 billion in sales for Trikafta since it was first approved in 2019.

Last week, a group of patients and their families in four countries on four continents initiated legal and regulatory steps to try to force their governments to override intellectual property protections and allow a low-cost generic version of Trikafta to be imported or made locally. Under the process, known as compulsory licensing, generic makers would pay Vertex a royalty.

Three of the actions are in India, Ukraine and South Africa — where Vertex has been obstructing efforts to make the drug available, patients and families say. The fourth is in Brazil, where Vertex is trying to win coverage for the drug; the patients' and families' concern there is that the brand-name drug will be too expensive.

Cystic fibrosis is a genetic disease that damages the lungs and digestive system. Patients often die in early adulthood, but Trikafta is dramatically extending life expectancy.

"Every patient in the world has access to the internet and wants this drug," said Christine Noke, a patient advocate in Turkey.

In theory, reaching patients in the developing world would bring in more revenue for a drug company. But some manufacturers resist making their drugs available in poorer countries at lower prices because doing so can erode their ability to charge more in high-income countries.

Vertex, which has a monopoly on transformative cystic fibrosis drugs, said it was pushing to increase access globally.

Spokesperson Heather Nichols said the company has begun a "product donation program" in low-income countries

The genetic defect that causes cystic fibrosis is most common in people of Northern European ancestry, as are the specific mutations needed for Trikafta to work. The number of cystic fibrosis patients in developing countries who are diagnosed and eligible for the drug is unknown but believed to number in the thousands.

Hemanth Buddana was given therapies and antibiotics for his frequent lung infections, but there was little available in India to help him breathe or gain weight. A genetic test confirmed that he would have been eligible for Trikafta.

The Medicines Patent Pool, a United Nations-backed nonprofit that brokers that process by issuing sublicenses to generic manufacturers, said it has had no contact with Vertex.