Shares of Advaxis (ADXS) are down 27% in after-hours trade after the company announced that the FDA has placed its HPV program on clinical hold due to one patient death. The stock had dropped as much as 18% today but then had rebounded to -8% at the close. The specific drug placed on hold is axalimogene filolisbac — previously known as ADXS-HPV. The halt affects four different trials, but only the HPV portion of the clinical trials. 

The prostate cancer and breast cancer trials are not affected at this time. The reason for the clinical hold is the one patient who took Advaxis' treatment back in 2013 for HPV. Subsequently in 2015 a few years later the patient was hospitalized for the end-stage cervical cancer, and at that time the patient was tested using blood samples, and the doctors discovered the Advaxis engineered bacteria in the bloodstream. 

The patient was then discharged at that time but a few weeks later came back to the hospital for the metastatic disease and passed away later that day. The investigator of the trial concluded that the death was due to the progression of the cervical cancer and not the treatment of Advaxis' axalimogene fibolisbac treatment. According to the company, the highly attentuated strain of the engineered bacteria is very susceptible to antibiotics, which were prescribed, but it is possible that implants the patient received during orthopedic procedures provided a site for the bacteria to ‘hide.'

Nevertheless, the FDA has decided to place a clinical hold on the drug until further investigation can be completed.

For now the FDA has requested additional information so they can conclude whether or not this patient death was due to the end-stage cancer and not the company's treatment with its listeria bacteria platform. Advaxis has stated that it has already provided the data to the FDA and now the company must await the response from the FDA before this clinical hold can be released.