What happened

Shares of Inovio Pharmaceuticals (INO 3.03%) were bouncing back on Thursday after being clobbered earlier this week. The stock was up 8.5% as of 11:05 a.m. EDT. 

Inovio didn't report any new developments. However, it appears that investors believe the sell-off was overdone following the company's announcement on Tuesday of interim results from an early stage clinical study of COVID-19 vaccine candidate INO-4800.

Healthcare professional holding a syringe and vial.

Image source: Getty Images.

So what

The biotech stock still has a long way to go to make up its lost ground. Inovio's shares were down 37% this week as of the close on Wednesday.

Investors reacted negatively to Inovio's lack of details in its interim results for INO-4800. The company said that 94% of participants "demonstrated overall immune responses" after receiving two doses of the experimental vaccine. However, Inovio didn't reveal how many patients had neutralizing antibodies that could prevent infection.

Inovio will provide more details from its phase 1 study of INO-4800 in the not too distant future, though. If the COVID-19 vaccine advances to a phase 2/3 study, the current suspicions about efficacy problems should largely fade away.

Now what

Investors should get some answers pretty soon. Inovio hopes to initiate the phase 2/3 study of INO-4800 this summer if the FDA gives a green light for the clinical trial. The company also plans to publish the full data from its phase 1 study of the COVID-19 vaccine candidate in a peer-review medical journal. At this point, though, the publication date is uncertain.