Researchers around the world have explored the ties between the immune system and devastating neurodegenerative diseases such as Alzheimer’s. San Francisco biotech Alector wants to exploit those ties to make drugs, and today it announced $32 million in venture funding—with another round likely coming by year’s end—to continue that work.

Alector was founded two years ago by bioengineering specialist and Dartmouth engineering professor Tillman Gerngross, former Genentech scientist Arnon Rosenthal, and Columbia University professor Asa Abeliovich. The aim is to go after neurodegeneration by stimulating the innate immune system—cells such as macrophages and microglia. Those cells, in turn, would work harder to prevent the misfolded proteins, often ending in clumps or tangles in patients’ brains, that are the hallmark of Alzheimer’s and other diseases.

I asked Rosenthal, the CEO, if there are lessons to be drawn from the red-hot field of cancer immunotherapy, which also aims to unleash the power of the immune system to fight disease. One branch of the field is developing antibodies that help “unmask” tumors that otherwise hide from the immune system’s T cells. These so-called checkpoint inhibitors have had success knocking down some severe skin cancers and a type of lung cancer, but as solo therapies they’re facing limitations, and companies are scrambling to test combinations of checkpoint antibodies and other drugs.

Alector is developing antibodies, too. The targets Alector is going after—proteins on the surfaces of innate immune cells in the brain—are different than cancer immunotherapy’s targets, but “the cell biology is similar,” says Rosenthal. ...

Prof Tillman Gerngross

... Alector chairman Gerngross said Alector set out to raise $10 million but within two months had rounded up $32 million, with MRL Ventures, the venture arm of drug giant Merck (NYSE: MRK), taking the lead. It’s strictly financial; Merck has no rights or ties to Alector’s work.

The cash isn’t contingent upon Alector hitting milestones, as venture rounds often are. A new “significant” investment is likely before the end of the year, Gerngross said.

One of Gerngross’s other startups, Adimab of Lebanon, NH, where he is CEO, is working with Alector to refine its antibodies. The companies also share an unusual investor, Google Ventures, which infrequently invests in biopharmaceutical companies. Google joined Alector’s Series C round, as did Mission Bay Capital and Topspin Partners. Previous investors OrbiMed Advisors and Polaris Partners also pitched in. Gerngross said Google Ventures has cashed out of its Adimab investment, which it first made in 2009.