Vir Biotechnology Inc. and Alnylam Pharmaceuticals Inc. are expanding an infectious disease collaboration begun three years ago to take on the coronavirus. The effort now includes developing and commercializing RNAi therapies targeting SARS-CoV-2, the virus that triggers COVID-19, by developing siRNAs identified by Alnylam.

Alnylam designed and synthesized more than 350 siRNAs that target all available SARS-CoV and SARS-CoV-2 genomes. That took about 48 hours to accomplish because the company has all the bioinformatic tools necessary, John Maraganore, Alnylam’s CEO, said Wednesday.

John Maraganore, CEO, Alnylam

“Now we’re screening them,” Maraganore told BioWorld. “We will end up delivering 50 to 100 potent molecules to Vir.”

Companies are announcing their efforts to fight COVID-19 every day. Nearly 30 other products are in development for coronavirus, just not specifically COVID-19, according to the Cortellis database.

The two companies will use Alnylam’s recent work in lung delivery of novel conjugates of siRNA, molecules that mediate RNAi, and San Francisco-based Vir plans to advance one or more siRNAs to treat SARS-CoV-2 and, if possible, other coronaviruses. The hardest part, Maraganore added, is making sure the company can scale up lung delivery.

The siRNAs will be screened by Vir for in vitro and in vivo antiviral activity, with the goal to select a development candidate. If that happens, Vir takes the lead on all development and commercialization efforts while Alnylam can share equally in the profits and losses. Alnylam may elect to earn development and commercialization milestones and royalties on net sales of products arising from the collaboration.

“In early January, when all of us were hearing about the beginning of the Wuhan epidemic, our scientists were reading about it, as we all were, and became interested because we have quite recently developed delivery approaches for small interfering RNAis to the lung in animal models,” Maraganore said.

Because SARS-CoV-2 is a respiratory virus, Maraganore said, his scientists became interested in the genomic sequences coming out of patients, having found “remarkable” sequence conservation between the emerging strain.

“That is very encouraging when you’re designing an RNAi-based drug,” he said, adding that the sequences probably can’t be altered easily by the virus.

The original deal between the two companies stems from a 2017 agreement to develop six siRNAs to treat infectious diseases.

This is Vir’s second coronavirus deal in the past two days. On Tuesday, Vir and Wuxi Biologics Co. Ltd., of Shanghai, announced plans to develop and produce human monoclonal antibodies for clinical development that Vir has found are able to bind to SARS-CoV-2, the virus that causes COVID-19. Those antibodies were isolated from people who recovered from SARS. Vir is carrying out work to determine if those antibodies can be effective as treatment and/or prophylaxis against SARS-CoV-2. Both companies are handling clinical development, manufacturing and commercialization of Vir’s antibodies.

Vir CEO George Scangos said a solution in addressing current and future outbreaks is to develop broadly neutralizing antibodies.

“Right now, we are looking very hard for antibodies that will neutralize COVID-19,” said Scangos. “In the longer term, we would like to identify coronavirus antibodies that will neutralize SARS, MERS, COVID-19 and hopefully the next coronavirus outbreak.”

To do that, he said one must look for antibodies that will neutralize two strains of coronavirus that are on the opposite end of the of the coronavirus evolutionary tree, so they are very divergent types of viruses.

Vir’s stock (NASDAQ:VIR) closed March 4 at $44.90, up 9.6%. Alnylam’s stock (NASDAQ:ALNY) had a more modest day, closing at $117.24, up 5.2%.