Nyxthracis (previously Obiltoxaximab SFL)

Obiltoxaximab SFL can only be obtained with a prescription and should be given in a place where severe allergic reactions can be quickly treated.

Obiltoxaximab SFL is given as a single infusion (drip) into a vein over 90 minutes. The recommended dose depends on the patient’s weight. Before Obiltoxaximab SFL is given, patients may be given medicines to prevent or reduce allergic reactions.

For more information about using Obiltoxaximab SFL, see the package leaflet or contact your doctor or pharmacist.

The serious effects of anthrax are caused by a toxin that the anthrax bacteria produce. Obiltoxaximab is a monoclonal antibody, a type of protein, which has been designed to attach to a component of the anthrax toxin called ‘anthrax protective antigen’ that allows the toxin to enter cells. By attaching to anthrax protective antigen, the medicine is expected to stop the toxin from entering the body’s cells, thereby reducing or preventing symptoms.

Obiltoxaximab SFL is considered effective at treating inhalational anthrax based on studies in animals. In 3 studies in infected animals with symptoms, the survival rates ranged between around 30 and 60% with Obiltoxaximab SFL, compared with 0 to 6% with placebo (dummy treatment). In a study where infected animals received the medicine or placebo before developing symptoms, survival ranged between 50 and 100% with Obiltoxaximab SFL, depending on how soon the animals received treatment after being infected, compared with none of those given placebo.

The most common side effects with Obiltoxaximab SFL (which may affect up to 1 in 10 people) are headache, pruritus (itching), urticaria (itchy rash), rash, cough, infusion site pain and feeling dizzy.

For the full list of side effects and restrictions of Obiltoxaximab SFL, see the package leaflet.

Inhalation anthrax is a life-threatening disease leading to death in 50% of cases. Although natural outbreaks are very rare, infections can occur by accident in laboratories studying the bacteria, and anthrax might be used in terrorist attacks. Because the number of cases is so low and deliberately infecting individuals is too dangerous, it is not feasible to carry out studies of the medicine in people. Studies in animals showed that the medicine is effective at treating anthrax and preventing death, and it is expected that Obiltoxaximab SFL will work in the same way in people. In terms of safety, the side effects of Obiltoxaximab SFL in healthy people are usually mild or moderate. The Agency therefore decided that Obiltoxaximab SFL’s benefits are greater than its risks and it can be authorised for use in the EU.

Obiltoxaximab SFL has been authorised under ‘exceptional circumstances’. This is because it has not been possible to obtain complete information about Obiltoxaximab SFL due to the rarity of the disease and for ethical reasons. Every year, the Agency will review any new information that becomes available and this overview will be updated as necessary.

Since Obiltoxaximab SFL has been authorised under exceptional circumstances, the company that markets Obiltoxaximab SFL will provide further data on methods for measuring how the medicine is absorbed, modified and removed from the body in laboratory studies. In addition, data on the effectiveness and safety of the medicine during a potential outbreak of anthrax should be submitted.

Recommendations and precautions to be followed by healthcare professionals and patients for the safe and effective use of Obiltoxaximab SFL have been included in the summary of product characteristics and the package leaflet.

As for all medicines, data on the use of Obiltoxaximab SFL are continuously monitored. Side effects reported with Obiltoxaximab SFL are carefully evaluated and any necessary action taken to protect patients.

Obiltoxaximab SFL received a marketing authorisation valid throughout the EU on 18.11.2020.