What happened

Shares of Vir Biotechnology (VIR 3.41%) were vaulting 12.8% higher as of 3:07 p.m. EST on Tuesday. The big jump came after the company announced news about separate collaborations with Gilead Sciences (GILD 0.33%) and GlaxoSmithKline (GSK -0.97%)

So what

Partnerships with big drugmakers often serve as positive catalysts for small biotech stocks. It's not surprising that Vir's updates about two different collaborations especially excited investors.

Scientist looking through microscope

Image source: Getty Images.

Vir and Gilead plan to work together on a phase 2 study evaluating Vir's VIR-2218 with Gilead's selgantolimod in treating individuals infected with the hepatitis B virus (HBV). In addition to this combo, study participants could also receive Gilead's HBV drug Vemlidy.

Vir and GlaxoSmithKline partnered last year to develop COVID-19 therapies. The two companies announced today that they intend to kick off a phase 2 study evaluating antibody therapy VIR-7832 in treating COVID-19 patients this quarter.

This new study with GSK was likely the bigger factor driving Vir's stock higher today. GSK invested $250 million in Vir in April 2020. No financial details of Vir's collaboration with Gilead were released. Each company will retain full rights to their products involved in the phase 2 study. Vir and Gilead stated that they "will discuss the potential path forward for any future combination studies based on the outcome of the phase 2 trial."

Now what

The next key catalyst for Vir could be on the way soon. Interim results from a late-stage study of VIR-7831, another antibody therapy included in Vir's collaboration with GSK, should be announced early this year.