Jonathan Drachman, MD
A supplemental Biologics License Application (sBLA) has been submitted to the FDA for brentuximab vedotin (Adcetris) as a treatment for patients with cutaneous T-cell lymphoma (CTCL), according to Seattle Genetics, which codevelops the antibody-drug conjugate with Takeda.
The sBLA is primarily based on the phase III ALCANZA trial, in which brentuximab vedotin induced responses lasting at least 4 months in 56.3% of patients versus 12.5% in patients receiving physician’s choice of standard therapies (P
“The submission of the supplemental BLA requesting label expansion for Adcetris as a treatment in CTCL patients who require systemic therapy is an important milestone. CTCL is an incurable and disfiguring disease in need of new therapeutic options, particularly those that achieve durable responses,” said Jonathan Drachman, MD, Chief Medical Officer and Executive Vice President, Research and Development of Seattle Genetics.
“Results from the phase 3 ALCANZA trial demonstrated that CTCL patients treated with Adcetris had superior outcomes across all primary and secondary endpoints compared to patients in the control arm who were treated with either methotrexate or bexarotene standard of care agents. In addition to the Adcetris results, data from 2 investigator-sponsored trials also support Adcetris use in this disease setting. We believe these data are clinically meaningful and support a label expansion for Adcetris in CTCL, which would be the fourth indication for this program.”
The international, open-label phase III ALCANZA trial included 131 patients with CD30-expressing (≥10% of infiltrate by central review) mycosis fungoides (MF) or primary cutaneous anaplastic large cell lymphoma (pcALCL), the 2 most common subtypes of CTCL. The intent-to-treat population comprised 128 patients, 97 with MF and 31 with pcALCL. Three patients were excluded because their CD30 expression level was too low.
Patients with MF had to have received at least 1 prior systemic therapy and those with pcALCL were required to have prior radiation therapy or at least 1 systemic therapy. Patient characteristics were generally well balanced at baseline. The median age was 62 years in the brentuximab vedotin arm and 59 years in the control arm, and the median number of prior systemic therapies overall was 4 (range, 2-6). At least 95% of patients in both arms had an ECOG performance status of 0 to 1. In the brentuximab vedotin arm, there were more pcALCL patients with extracutaneous disease (44% vs 27%).
Patients were randomized in a 1:1 ratio to the anti-CD30 antibody-drug conjugate brentuximab vedotin (n = 64) or physician’s choice of the standard treatments methotrexate or bexarotene (n = 64). Brentuximab vedotin was administered intravenously at 1.8 mg/kg once every 3 weeks and for up to 48 weeks (16 cycles). Methotrexate was dosed at 5 to 50 mg once weekly and bexarotene was administered orally at 300 mg/m2
once daily. Treatments were administered until disease progression or unacceptable toxicity.
Beyond the primary endpoint of objective response rate lasting ≥4 months (ORR4), secondary outcome measures included complete response (CR) rate, progression-free survival (PFS), and reduction in the burden of symptoms during treatment.
At a median follow-up of 22.9EC months, the median PFS was 16.7 months with brentuximab vedotin versus 3.5 months with physician’s choice (HR, 0.270; 95% CI, 0.169-0.430; P
<.0001). The ORR was 67% (n = 43) versus 20% (n = 13; P
<.0001), with CR rates of 16% versus 2% (P
= .0046), in the brentuximab vedotin and control arms, respectively. Symptom reduction, as measured by Skindex-29, was significantly better with brentuximab vedotin versus physician’s choice (-27.96 vs -8.62; P
Among patients with MF who received brentuximab vedotin, the ORR4 was 50% versus 10% with physician’s choice. The ORR and CR rates were 65% versus 16% and 10% versus 0, respectively. In patients with pcALCL who received brentuximab vedotin, the ORR4 was 75% versus 20% with physician’s choice. The ORR and CR rates were 75% versus 33% and 31% versus 7%, respectively.
In patients with pcALCL in the skin only who received brentuximab vedotin, the ORR4 was 89% versus 27% with physician’s choice. The ORR and CR rates were 89% versus 45% and 44% versus 9%, respectively. Among pcALCL patients with extracutaneous disease who received brentuximab vedotin, the ORR4 was 57% versus 0 with physician’s choice. The ORR and CR rates were 57% versus 0 and 14% versus 0, respectively.