Adaptimmune Therapeutics is prepping for another FDA submission after 42% of patients with sarcoma responded to the company's investigational cell therapy in a pivotal phase 2 trial.
The primary analysis includes 64 patients with previously treated, advanced synovial sarcoma or myxoid/round cell liposarcoma (MRCLS). The open-label study, dubbed IGNYTE-ESO, is evaluating lete-cel, Adaptimmune’s engineered T-cell receptor therapy.
The data show that 42% of patients (27/64) patients experienced clinical responses—meeting the study’s primary endpoint—with six complete responses and 21 partial responses being recorded. This is up slightly from the 40% (18/45) overall response rate shared at this year’s American Society of Clinical Oncology meeting.
The new analysis, when stratified by cancer type, reveals a response rate of 41% (14/34) in synovial sarcoma and 43% (13/30) for MRCLS.
The median duration of response was 12.2 months, with a median duration of response of 18.3 months in synovial sarcoma and 12.2 months in MRCLS, according to Adaptimmune. The company recorded a median progression-free survival duration of 5.3 months.
All patients experienced treatment-emergent adverse events, Adaptimmune said. The most common adverse events were cytopenias, cytokine release syndrome and rash. Specific data about adverse event grade levels were not shared, but the biotech said, “Overall, toxicities were manageable and consistent with an acceptable benefit to risk profile,” in the Nov. 13 release.
Investigators will present the results Nov. 16 at the Connective Tissue Oncology Society annual meeting in San Diego.
Given the results, the cell therapy biopharma plans on initiating a rolling biologics license application submission for lete-cel in the two cancer indications by the end of next year.
"Individuals with both synovial sarcoma and MRCLS are commonly diagnosed under 40, facing a devastating disease with limited treatments in the prime of their lives,” Sandra D'Angelo, M.D., investigative clinician for IGNYTE-ESO and a sarcoma oncologist and cell therapist at Memorial Sloan Kettering Cancer Center, said in the company release. “I've been seeing these patients throughout my career and have frequently faced the frustrating reality of having incredibly limited treatment options to offer them. I'm encouraged by these data as they could lead to a potential therapeutic option and an improved prognosis for these patients."
Adaptimmune is set to discuss the data during a virtual event Monday, Nov. 18. The cell therapy specialist is also hosting a quarterly earnings call today at 4:30 p.m. ET.
The new data drop follows the FDA approval of Adaptimmune’s afami-cel, known under the brand name of Tecelra, for metastatic or unresectable synovial sarcoma. The accelerated nod came in August, with Tecelra becoming the first engineered cell therapy for a solid tumor to ever snag approval, plus the first TCR-T therapy to enter the market and the first new treatment in the indication in more than a decade.
Despite the historic approval, Adaptimmune’s stock fell after snagging the market nod, perhaps at the prospect of going at the launch alone.
The cell therapy biotech had been buoyed by a $3 billion biobucks partnership with Genentech, a deal the Roche subsidiary terminated in April. Just seven weeks later, Adaptimmune was able to secure a $665 million deal with Galapagos, giving the company rights to uza-cel, a MAGE-4A TCR T-cell therapy. The Galapagos deal, which included $100 million upfront, was used to help fund Adaptimmune’s launch of Tecelra.