Cellectis suffers worst day in two years after Pfizer event disappoints investors

Cellectis ($CLLS) suffered its worst day in two years on the Paris stock exchange on Monday. The 13% slump began when it became clear that a conference call held by Cellectis, Pfizer ($PFE) and Servier would do little more than clarify the roles of each party in their recently struck CAR-T collaboration.

Cellectis CEO André Choulika

Paris, France-based Cellectis scheduled the joint conference call with its UCART19 development partners late last week, prompting speculation about what details or events the companies were gathering investors to discuss. Ultimately, little of note was disclosed. When it became clear that this would be the case, something that happened around 2:12 p.m. Paris time, investors voted with their wallets and sent shares in Cellectis into a steep decline. Cellectis shares traded on Nasdaq followed suit when the market opened later that day.

The dropoff was exacerbated by broader negative sentiment toward biotech stocks on the back of perceived disappointment with some of the data presented at the American Society of Hematology (ASH) meeting. Cellectis got caught up in the bloodletting despite ASH and its conference call being something of a nonevent in terms of the future of UCART19 and its in-house pipeline. University College London presented data on the 11-month-old girl who was treated with Cellectis' cell therapy on a compassionate use basis earlier this year, but the big revelations broke last month.  

Similarly, the conference call was more about clarifying the details of UCART19 development now that Servier has picked up the program and flipped the U.S. rights to Pfizer. Servier approached Cellectis about bringing forward the time at which it could exercise its option on UCART19--an event originally scheduled for after the Phase I trial--and this led to the amended deal. With Servier and Pfizer now taking on development of UCART19, Cellectis will focus its attention on UCART123 and the rest of its remaining internal pipeline.

Cellectis is developing UCART123 as a treatment for acute myeloid leukaemia and the rare disease blastic plasmacytoid dendritic cell neoplasm. Management is keeping tight lipped about when the program could enter the clinic, though. None of this is typically stock-moving news, but the absence of anything stronger to report meant it became so on Monday. 

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