Atara Biotherapeutics (ATRA) rallied on Friday after announcing FDA clearance for two Phase 3 studies to evaluate tabelecleucel (formerly known as ATA129). Today, the company announced that it's ready to enroll patients.
Before getting to the news, a little background would help since most people are not familiar with the company. Atara Biotherapeutics is a T-cell immunotherapy company developing treatments for patients with cancer, autoimmune and viral diseases. The company's off-the-shelf, or allogeneic, T-cells are bioengineered from donors with healthy immune function and allow for rapid delivery from inventory to patients without a requirement for pretreatment.
Atara's T-cell immunotherapies are designed to eliminate cancerous or diseased cells without affecting normal, healthy cells. Its most advanced T-cell immunotherapy in development, tabelecleucel (formerly known as ATA129), is being developed for patients with rituximab-refractory Epstein-Barr virus (EBV) associated post-transplant lymphoproliferative disorder (EBV+PTLD), as well as other EBV associated hematologic and solid tumors, including nasopharyngeal carcinoma (NPC).
Tabelecleucel is in Phase 3 development for the treatment of EBV+PTLD following an allogeneic hematopoietic cell transplant (MATCH study) or solid organ transplant (ALLELE study), and a Phase 1/2 study of tabelecleucel in combination with Merck's anti-PD-1 (programmed death receptor-1) therapy, KEYTRUDA (pembrolizumab), in patients with platinum-resistant or recurrent EBV associated NPC is planned for 2018.
A bit about EBV+PTLD: Since its discovery as the first human oncovirus, EBV has been implicated in the development of a wide range of lymphoproliferative disorders, including lymphomas and other cancers. EBV is widespread in all human populations and persists as a lifelong, asymptomatic infection. In immunocompromised patients, such as those undergoing allogeneic hematopoietic cell transplants (HCT) or solid organ transplants (SOT), EBV+PTLD represents a life-threatening condition.
Turning to today's news, Atara announced the initiation of two Phase 3 clinical studies to evaluate tabelecleucel in patients with EBV+PTLD. Three clinical sites for both the MATCH and ALLELE pivotal studies are now open for enrollment in the US and the studies will later expand to additional US sites as well as sites in the EU, Canada and Australia. The company says it's ready to enroll patients.
This news comes after its Friday announcement that Atara received clearance from the FDA to initiate the two Phase 3 studies, which Atara describes as a major milestone. This achievement included extensive collaboration with the FDA under Breakthrough Therapy Designation and Atara expects tabelecleucel will be the first off-the-shelf T-cell immunotherapy to begin Phase 3 development in the US.
Results from the first tabelecleucel Phase 3 study to reach the primary endpoint are expected to be announced in 1H19. Atara also plans to submit a tabelecleucel Conditional Marketing Authorization (CMA) application in the EU for patients with EBV+PTLD following HCT during 1H19.
In sum, the stock jumped 19% on Friday when the FDA clearance was announced. It's not moving much today. But this is an important milestone for Atara. The stock has been range-bound in the $14-18 area since May 2017. It reached a high of $21.80 on Friday before pulling back, but still had a nice gain for the day. This was clearly some good news for Atara.