A proposition that would keep alive California’s first-of-its-kind stem cell research program with a $5.5 billion infusion of borrowed money had a narrow lead.

With about 11 million votes counted, approval for Proposition 14 was ahead 51% to 49% late Tuesday night.

If the proposition passes it would approve a bond sale that would bail out the California Institute for Regenerative Medicine, which was created by a similar $3 billion bond measure in 2014 but is now nearly broke. Millions more votes remained to be counted.

With dozens of clinical trials involving the use of stem cells to treat cancer, Alzheimer’s disease, Parkinson’s disease, paralysis, autoimmune diseases and other conditions underway at universities across California, supporters say it is crucial to keep that money flowing.

Professor Larry Goldstein, who directs the stem cell research program at the University of California, San Diego, called the early results “very encouraging.”

“I am cautiously optimistic and hopefully happy that the voters of California saw fit to approve this important initiative,” he said.

Goldstein said trials using stem cells to treat diabetes, blindness and spinal cord injury are early but showing signs of benefit, and losing them would be a tragedy for those patients.

Opponents say the state simply can’t afford to take on that kind of debt during a pandemic-induced economic crisis. What’s more, they say, there isn’t as much need for California to bankroll stem cell research now that the federal government and private investors have turned their attention to it.

“We built something good, but I think the field has expanded and there’s plenty of money going into research in California now,” said Jeff Sheehy, who sits on the governing board of the California Institute for Regenerative Medicine but says the state can’t afford to borrow more bond money to support it.

When voters approved the initial $3 billion in 2004, President George W. Bush’s administration had banned the use of federal funds for research using newly created human embryonic stem cell lines. The Obama administration lifted that ban in 2009.

Since then, opponents say, the National Institutes of Health has provided $1.5 billion a year in stem cell research money, while private investment in companies doing stem cell research has flowed in.

Supporters say that federal money could stop at any time, noting more than 90 members of Congress recently signed a letter demanding the Trump administration put an end to funding stem cell research.

More than a third of the initial $3 billion was spent to create stem cell research facilities at Stanford, the University of California, Berkeley, and other prestigious California institutions. Much of the rest has gone toward research.

With only about $30 million left, the California Institute for Regenerative Medicine has reduced its staff and stopped funding new studies.

If the proposition keeps its lead and passes, at least $1.5 billion would be earmarked for developing treatments for Alzheimer’s, Parkinson’s and other brain-related diseases. Some funds would be used to train California university and college students, and no more 7.5% could be used for administrative costs.

The state Legislative Analyst’s Office estimates that paying off the bonds with interest over 30 years would cost $7.8 billion.

Some of that money could be recouped through the sale of new treatments created by the research, according to the analyst’s office. Other such revenue could be used to pay for patient treatments.

The office didn’t estimate how much money might be generated but said research conducted since 2004 has resulted in “a few hundred thousand dollars in invention-related income.”