FDA Advises Against an Approval Filing for Camidanlumab Tesirine to Treat R/R HL

The FDA provided strong guidance against ADC Therapeutics submitting a biologics license application (BLA) for camidanlumab tesirine (ADCT-301) as treatment of patients with relapsed or refractory (r/r) Hodgkin lymphoma, during a Type C meeting.¹

Based on the FDA’s advice, a BLA will not be submitted for the drug in 2023. The company plans to conduct a randomized phase 3 confirmatory study for which enrollment is estimated to take 2 years. Meetings between the FDA and ADC Therapeutics will be ongoing as the company continues to develop camidanlumab tesirine.

Camidanlumab tesirine for the treatment of r/r Hodgkin lymphoma was assessed in a phase 2, open-label, single-arm study (NCT04052997). Results from 117 heavily pretreated patients showed that the agent is effective in this patient population. The findings were presented at the Society of Hematologic Oncology (SOHO) Annual Meeting.^1,2

The study had primary end point of objective response rate (ORR) and assessed duration of response (DOR), progression-free survival (PFS), and safety as secondary end points. The patients enrolled were 18 years of age or older with a pathologic diagnosis of classical Hodgkin lymphoma and had received 3 or more prior line of systemic therapy. Patients also received prior treatment with brentuximab vedotin (Adcetris) and PD-1 inhibitor therapy Patients were required to have measurable disease, and ECOG performance status, and adequate organ function to enroll.²

Patients enrolled were administered a 30-minute intravenous infusion camidanlumab tesirine on day 1 of each 3-week cycle. During cycles 1 and 2, the dosage administered was 45 µg/kg, and during cycles 3 and up, the dosage administered was 30 µg/kg.

At a median follow-up of 10.7 months, the objective response rate was 70.1% (95% CI, 60.9%-78.2%). Responses consisted of complete responses (CRs) in 33.3%, partial responses (PRs) in 36.8%, and stable disease in 17.9%. Responses were not evaluable in 5.1% of patients, and 6.8% had progressive disease. The median duration of response was 9.1 months.

Camidanlumab tesirine also achieved a median progression-free survival of 9.10 months (95% CI, 5.13-15.01) in the all-treated population.

In terms of safety, any-grade treatment-emergent adverse events (TEAEs) were observed in 99.1% of patients. The most common any-grade TEAEs were fatigue (38.5%), maculopapular rash (32.5%), and pyrexia (29.9%). Grade ≥3 TEAEs were observed in 9.4% of patients. The most common grade ≥3 TEAEs were anemia (8.5%), Hypophosphatemia (7.7%), and neutropenia (7.7%). Any-grade pyrrolobenzodiazepine dimer-related TEAEs occurred in the study and consisted of skin/nail reactions (74.4%), hepatobiliary test abnormalities (29.1%), and edema/effusion (17.1%). Grade ≥3 pyrrolobenzodiazepine dimer-related TEAEs also occurred.

Immune-related AEs were observed in 32.5% of patients. The events were grade ≥3 in 10 patients. Overall, the safety profile of camidanlumab tesirine in the study was consistent with prior findings.

_REFERENCES:

_{1. ADC Therapeutics reports third quarter 2022 financial results and provides business updates. News release. ADC Therapeutics. November 10, 2022. Accessed November 10, 2022. https://bit.ly/3TsseSN}

_{2. Carlo-Stella C, Ansell S, Zinzani PL, et al. Camidanlumab Tesirine: Updated efficacy and safety in an open-label, multicenter, phase 2 study of patients with relapsed or refractory classical hodgkin lymphoma (R/R cHL). Presented at: 10th Annual Meeting of the Society of Hematologic Oncology (SOHO 2022); September 28-October 1, 2022; Houston TX.}