ASCO24: Pfizer, Takeda's Adcetris achieves unexpected survival success in DLBCL

Results unveiled at the American Society of Clinical Oncology (ASCO) annual meeting revealed that Pfizer and Takeda's medication, Adcetris (brentuximab vedotin), significantly reduced the risk of death by 37% in patients suffering from relapsed or refractory diffuse large B-cell lymphoma (DLBCL). These findings stem from the Phase III ECHELON-3 study. In a somewhat unexpected announcement made in March, the companies revealed that the trial had achieved its primary endpoint. Adcetris, when combined with lenalidomide and rituximab, demonstrated a statistically significant and clinically vital improvement in overall survival (OS) compared to a placebo combined with lenalidomide and rituximab.

At the ASCO meeting, detailed results showed that the median overall survival for patients administered the CD30-targeted antibody-drug conjugate was 13.8 months, as opposed to 8.5 months in the placebo group. The survival benefit was consistent across crucial subgroups, including different levels of CD30 expression.

The surprising results from ECHELON-3 came after Seagen, a company acquired by Pfizer for $43 billion and the original developer of Adcetris, had previously decided to deprioritize the study. Seagen had even labeled the study as “no longer…registrational” shortly after the primary endpoint was shifted from progression-free survival (PFS) to overall survival (OS).

Data presented at the ASCO meeting further disclosed that the median progression-free survival was 4.2 months for patients on the Adcetris regimen compared to 2.6 months for those on placebo. The objective response rate was 64.3% in the Adcetris group versus 41.5% in the placebo group, with complete response rates of 40.2% and 18.6%, respectively.

Adcetris is already approved for use as a standalone therapy or in combination with chemotherapy for seven forms of lymphoma, including specific types of classical Hodgkin lymphoma, anaplastic large cell lymphoma, and peripheral T-cell lymphoma. Roger Dansey, Pfizer’s chief development officer for oncology, highlighted that “Adcetris is a standard-of-care medicine in its approved indications.” He added that the “impressive results from an interim analysis” of the ECHELON-3 study underscore the drug’s potential to significantly benefit individuals with relapsed or refractory DLBCL, irrespective of their CD30 expression levels.