Lecanemab killing people??

There has been a great deal of enthusiasm for lecanemab following the seemingly positive results of Biogen's phase 3 clinical trial.  Only one problem ... two test subjects died during the trial.  Biogen and their partner, Esai, made a statement claiming the deaths were not a consequence of the use of lecanemab, but rather significant comorbidities in the subjects.  But now there has been a third death.  Neuroscientists recruited by Science.org (publication of American Association for the Advancement of Science) reviewed the medical records of the Florida woman who died in the third case and concluded her death was most likely caused by lecanemab.

All of the "mabs" (monoclonal antibodies) cause brain swelling and microhemorrhaging  But, until lecanemab, none of these led to any deaths.  If you take Aduhelm, the first mab treatment to be approved by the FDA, you must get regular MRIs to check for swelling and microhemorrhaging.  And while there were no deaths during the clinical trials for aducanumab (now marketed as Aduhelm) at least one patient being treated with Aduhelm has now died.  This was apparently a consequence of using the mab.

So what do Biogen and Esai have to say about the new death?  I don't know.  I've visited the press rooms of both companies, and I can't find anything they've said yet.

There is nothing new about patients dying during clinical trials or even from drugs that have been approved by the FDA.  Of course, the diseases they hope to treat are themselves even more deadly.  The hope is that the inevitable risks are well understood and weighed before beginning a course of treatment.  And one purpose of drug trials is to measure previously unknown risks and effects of taking an experimental drug.  I'm waiting to see what Esai, Biogen, and the scientists engaged in testing and understanding the risks and rewards associated with mab treatments have to say about the safe testing and and use of lecanemab and other mabs.