What happened

Shares of Alaunos Therapeutics (TCRT -3.88%) are soaring today, up by 26.3% as of 10:55 a.m. ET. The big gain came after a 38% plunge on Thursday.

Yesterday's sell-off was sparked by an online update about the status of one of the patients in Alaunos' ongoing phase 1/2 clinical study evaluating its T-cell receptor (TCR) therapy. The rebound for the biotech stock today probably reflected some acknowledgment by investors that the initial response to the report on Thursday was overdone.

So what

Alaunos announced early clinical data from its phase 1/2 study on Sept. 6, 2022. The company stated that the first patient doses achieved a confirmed objective partial response (shrinking of tumor). It also reported that the second patient has been dosed.

On Thursday, though, investors reacted negatively to a post on the fundraising website GiveSendGo.com about patient No. 2. While this patient initially had a positive response to Alaunos' cell therapy, the post raised questions about the possibility that her cancer had mutated. 

It's not unusual for intense scrutiny to be given to any public comments from patients or their caregivers about experimental therapies. However, those comments often don't provide all of the context needed for investors to know the full story.  

Now what

Alaunos' shares will likely remain highly volatile until more solid information is available. The company plans to present data from its phase 1/2 study on Sept. 30 at the International Cancer Immunotherapy Conference (CICON). This update could shed more light on the status of patient No. 2.