Grifols ponies up $80M for polyclonal antibody biotech GigaGen

Grifols
The GigaGen buyout comes six months after Grifols acquired Alkahest and its pipeline of medicines for neurodegenerative and age-related diseases for $146 million. (Grifols)

Grifols picked up a 44% stake in GigaGen in 2017 when the duo teamed up to develop polyclonal antibodies under a $50 million pact. Now, the Spanish pharma is dropping $80 million to acquire the remaining 56% of its partner.

GigaGen brings with it a pipeline of preclinical-stage recombinant polyclonal antibodies in development for primary immune deficiency and infectious diseases such as COVID-19. It is also developing recombinant monoclonal antibody treatments for various cancer targets including CTLA-4, PD-L1 and TGF-beta.

The programs are based on the company’s Surge technology, which uses single-cell sequencing to “capture and recreate” whole libraries of antibodies from different people, such as patients who have recovered from COVID-19. From those libraries, the company can choose which of those antibodies to turn into recombinant polyclonal antibody treatments.

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It’s an approach GigaGen hopes could be a better alternative to plasma-based treatments, known as hyperimmune globulins—and Grifols has bought in.

“These drugs right now are made by taking plasma from human donors or animals, purifying antibodies from it, which then become a drug. It’s like a cocktail of antibodies,” GigaGen CEO David Johnson, Ph.D., said in a previous interview.

The challenge is this approach is hard to scale, and it doesn’t pick out specific antibodies against the disease in question.

“You need many, many hundreds of donors to make a fairly small batch of product, and then you have to go out and find more donors—it’s not a very scalable approach,” Johnson said. “In your serum, you have antibodies against all kinds of diseases, and those diseases might have been ones you saw months ago and not necessarily coronavirus,” he said.

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In March, Grifols teamed up with the U.S. Biomedical Advanced Research Development Authority, the FDA and other federal agencies to develop a hyperimmune globulin against the SARS-CoV-2 virus. Its acquisition of GigaGen will add GIGA-2050, a treatment containing 12,500 of the most potent COVID-19 antibodies to shut down replication of the coronavirus. Although GIGA-2050 could be given as a prophylactic, Johnson sees it more as a therapeutic as it must be given to patients intravenously.

In August, GigaGen reported that GIGA-2050 was 100 times more protective than plasma from COVID-19 survivors in lab tests. The treatment’s next stop will be a phase 1 study in spring that will test it in up to 18 hospitalized patients with confirmed COVID-19.

The GigaGen buyout comes six months after Grifols acquired Alkahest and its pipeline of medicines for neurodegenerative and age-related diseases for $146 million. Grifols also snagged three antibiotics programs from struggling antibiotics developer Aradigm in early 2020, waiving a $32 million debt and paying $3 million in cash for the assets.