ADC Therapeutics presents updated clinical data for large B-cell lymphoma drug

ADC Therapeutics SA (NYSE: ADCT), a commercial-stage biotechnology company leading the development of novel antibody drug conjugates (ADCs) to treat hematological malignancies and solid tumors, today announced updated clinical data from the ZYNLONTA™ (loncastuximab tesirine-lpyl) Phase 2 LOTIS-2 trial in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) were presented at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting, which is being held virtually June 4-8, 2021.

“The maturing duration of response from the ZYNLONTA Phase 2 trial reported at ASCO reflects the strong data set that served as the basis of the accelerated FDA approval in April,” said Jay Feingold, MD, PhD, Senior Vice President and Chief Medical Officer of ADC Therapeutics. “We are especially encouraged to see this positive trend continue to strengthen in a heavily pre-treated patient population, including patients with double- / triple-hit, advanced stage or transformed DLBCL, DLBCL refractory to first-line therapy, and patients older than 65.”

In LOTIS-2, a single-arm, open-label, 145-patient Phase 2 clinical trial in patients with relapsed or refractory DLBCL who had failed ≥2 established therapies, ZYNLONTA demonstrated continued substantial antitumor activity and an acceptable safety profile. Updated results, including analysis of response in high-risk subgroups, were presented in a poster (abstract number: 7546) by Paolo F. Caimi, MD, University Hospitals Cleveland Medical Center and Case Comprehensive Cancer Center, Case Western Reserve University.

Key data at the March 1, 2021 data cut include:

• Overall response rate (ORR) was 48.3% and complete response rate (CRR) was 24.8%
• Median duration of response (mDoR) of 13.4 months for the 70 responders
• Median duration of response not reached for patients with a complete response
• Durable responses in high-risk patient groups, including:
• Patients with double- / triple-hit or transformed DLBCL each had a median DoR not reached
• Patients with advanced stage disease (Stage III-IV) had a median DoR of 12.6 months
• Median DoR for older patients was longer than for younger patients (≥75 years, not reached; ≥65 years to <75 years, 12.6 months; <65 years, 9.3 months)
• Patients with DLBCL refractory to first-line systemic therapy had a median DoR of 9.6 months compared with 12.6 months for patients who relapsed after responding to initial therapy
• No new safety concerns were identified during the study and no increase in toxicity was observed in patients aged ≥65 years compared with patients <65 years

Two additional posters presented at the 2021 ASCO Annual Meeting:

• Phase 3 randomized study of loncastuximab tesirine plus rituximab versus immunochemotherapy in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL): LOTIS-5 (abstract number: TPS7574)
• A Phase 1b, open-label, dose-escalation study to evaluate camidanlumab tesirine (Cami) as monotherapy in patients (pts) with advanced solid tumors (abstract number: 2556)