NEW YORK (Reuters) - U.S. drugmaker Pfizer Inc PFE.N said on Thursday that early data has helped it identify a drug candidate with the potential to help treat patients infected with the novel coronavirus.

FILE PHOTO: A logo of American pharmaceutical corporation Pfizer Inc., is pictured in Toluca, Mexico October 1, 2018. REUTERS/Edgard Garrido

It also finalized a plan to develop a coronavirus vaccine in partnership with German drugmaker BioNTech SE 22UAy.F and said the companies hope to produce millions of vaccines by the end of 2020. The companies said they plan to start trials of the vaccine as early as this month.

Data from preclinical studies of a compound that was originally developed to treat SARS - a different coronavirus that caused a major epidemic in 2003 - shows its potential to treat patients with the new coronavirus, Pfizer research chief Mikael Dolsten told Reuters in an interview.

Pfizer said it will conduct additional preclinical studies of the drug and aims to begin trials in humans in the third quarter of 2020.

In addition, Pfizer said it plans to support studies to determine whether existing Pfizer medicines, including its rheumatoid arthritis drug Xeljanz, may provide benefits for those struggling with the COVID-19 respiratory illness caused by the coronavirus.

“Pfizer has mobilized resources and capabilities to address every single frontier of the COVID-19 pandemic,” Dolsten said.

More than a dozen large drugmakers, including Pfizer, have announced plans in recent months to develop vaccines and treatments for the coronavirus, although few if any are likely to reach patients in time to stem the current outbreak.

Reuters last month was first to report Pfizer’s planned collaboration with BioNTech on a vaccine based on messenger RNA technology.

Pfizer will pay BioNTech $185 million upfront to develop the vaccine, with additional payments if certain milestones are achieved that could boost its total investment to nearly $750 million, the companies said.

Pfizer will help manufacture any eventual product and said it aims produce hundreds of millions of vaccines next year.

The largest U.S. drugmaker also announced a five-point plan for confronting the virus that includes collaborating with outside companies and institutions on the research, development and manufacture of treatments.

Meanwhile, Pfizer will help fund a study into whether Xeljanz, which belongs to a class of drugs called JAK inhibitors and also treats the autoimmune disease ulcerative colitis, can help patients with pneumonia caused by COVID-19.

Rheumatoid arthritis treatments from other drugmakers that work differently than Xeljanz are also being studied as possible COVID-19 treatments.

Pfizer is also looking into the potential of other drugs that work on the immune system to help coronavirus patients, the company said.

The company is also working with the Liverpool School of Tropical Medicine on two studies to better understand the relationship between coronavirus and pneumonia, which plays a role in many deaths caused by the virus that attacks the lungs.

Pfizer will also publish a review of research into whether its antibiotic azithromycin, sold under the brand name Zithromax, can play a role in treating COVID-19.

Azithromycin has been used with the malaria drug hydroxychloroquine by some doctors after a French study suggested the combination might benefit some COVID-19 patients.