8-K: ADC Therapeutics' ZYNLONTA Trial Meets PFS Endpoint

ADC Therapeutics announced topline data from its Phase 3 LOTIS-5 trial, showing ZYNLONTA in combination with rituximab met its primary endpoint for progression-free survival in relapsed or refractory diffuse large B-cell lymphoma.

Summary

• ADC Therapeutics announced topline results from the Phase 3 LOTIS-5 trial evaluating ZYNLONTA (loncastuximab tesirine-lpyl) in combination with rituximab for patients with relapsed or refractory diffuse large B-cell lymphoma (r/r DLBCL).
• The trial met its primary endpoint of progression-free survival (PFS) with statistical significance, showing a median PFS of 6.1 months for ZYNLONTA plus rituximab compared to 4.7 months for the standard treatment (R-GemOx).
• Overall survival showed no detrimental effect with the ZYNLONTA combination.
• The combination demonstrated a higher overall response rate (ORR) of 58.1% versus 45.2% and a higher complete response (CR) rate of 39.5% versus 26.7% compared to R-GemOx.
• Duration of response (DOR) and duration of complete response (DoCR) were also longer for the ZYNLONTA combination.
• Treatment-emergent adverse event (TEAE) rates were similar between arms, though serious adverse events (SAEs) and Grade 5 TEAEs were higher in the ZYNLONTA plus rituximab arm, particularly in patients aged 75 and older.
• ADC Therapeutics plans to engage with the U.S. FDA for a pre-Supplemental Biologics License Application (sBLA) meeting in August and aims for an sBLA submission in the fourth quarter of 2026.

Sentiment

Score: 7

Explanation: StockSavvy.ai views this as a positive development, as the trial met its primary endpoint and showed improved efficacy metrics, paving the way for regulatory submission, despite some safety concerns.

Positives

• The LOTIS-5 trial met its primary endpoint of progression-free survival (PFS) with statistical significance (HR = 0.73; p-value = 0.008).
• Median PFS was 6.1 months for ZYNLONTA plus rituximab, compared to 4.7 months for R-GemOx.
• Overall response rate (ORR) was higher at 58.1% for ZYNLONTA plus rituximab versus 45.2% for R-GemOx.
• Complete response (CR) rate was significantly higher at 39.5% for ZYNLONTA plus rituximab versus 26.7% for R-GemOx.
• Median duration of response (DOR) was 9.2 months for ZYNLONTA plus rituximab versus 7.7 months for R-GemOx.
• Median duration of complete response (DoCR) was 16.8 months for ZYNLONTA plus rituximab versus 12.3 months for R-GemOx.
• A higher proportion of patients achieving CR remained in CR at 24 months with ZYNLONTA plus rituximab (48.5% vs. 16.7%).
• Results in North America were consistent with overall study findings.

Negatives

• Serious adverse events (SAEs) were higher in the ZYNLONTA plus rituximab arm (49.0% vs. 34.5%).
• Grade 5 treatment-emergent adverse events (TEAEs) were higher in the ZYNLONTA plus rituximab arm (13.2% vs. 4.6%).
• Higher rates of TEAEs leading to drug withdrawal were observed in the ZYNLONTA plus rituximab arm (25.5% vs. 9.1%).
• Specific Grade 3 TEAEs such as infection/infestations, hepatotoxicity, and oedema/effusion were higher in the ZYNLONTA plus rituximab arm.

Risks

• The adequacy of the LOTIS-5 clinical trial data to support full regulatory approval.
• The ability to maintain accelerated approval in the United States and foreign jurisdictions.
• The timing, content, and outcome of meetings with regulatory authorities, including the U.S. FDA.
• The actual and perceived benefit-risk profile for ZYNLONTA as studied in the LOTIS-5 trial.
• The path for full regulatory approval for ZYNLONTA in the United States and foreign jurisdictions.
• The Company's ability to identify and execute value-maximizing options and the cost and impact of such options.
• The Company's indebtedness and the restrictions imposed by lenders.
• Uncertainties of international trade policies, tariffs, sanctions, and trade barriers.

Future Outlook

ADC Therapeutics plans to conduct a pre-Supplemental Biologics License Application (sBLA) meeting with the U.S. FDA in August 2026 and is preparing for a planned sBLA submission in the fourth quarter of 2026. The company will also continue to evaluate value-maximizing alternatives, including cost reduction initiatives. The company expects its cash runway to extend into at least 2028.

Management Comments

• "In the context of a positive study, based on the totality of the data, we plan to discuss the benefit-risk profile of this combination with the U.S. FDA as we prepare for the planned supplemental Biologics License Application (sBLA) filing."
• "We would like to extend our thanks to the patients, investigators, and clinical teams who contributed to this important trial."
• "Based on these results, I believe this combination may provide an additional option in treating relapsed or refractory DLBCL."
• "We look forward to discussing next steps for this combination of ZYNLONTA plus rituximab with the U.S. FDA. We intend to conduct a pre-sBLA meeting in August and are preparing for a planned sBLA submission in the fourth quarter of 2026."

Industry Context

StockSavvy.ai notes that the positive topline results for ZYNLONTA in combination with rituximab in the LOTIS-5 trial represent a significant step for ADC Therapeutics in the competitive r/r DLBCL market. The data suggests a potential new treatment option that could compete with existing immunochemotherapy regimens and potentially carve out a niche against more complex therapies like CAR-T.

Comparison to Industry Standards

• The LOTIS-5 trial compared ZYNLONTA plus rituximab against R-GemOx (rituximab gemcitabine-oxaliplatin), a standard immunochemotherapy regimen for r/r DLBCL.
• The median PFS of 6.1 months for ZYNLONTA plus rituximab compares favorably to historical benchmarks for second-line DLBCL treatments, though direct comparisons are complex due to differing patient populations and trial designs.
• The ORR of 58.1% and CR rate of 39.5% for the ZYNLONTA combination are competitive within the r/r DLBCL landscape, where response rates can vary significantly based on patient factors and prior treatments.

Stakeholder Impact

• Shareholders: Positive impact expected from potential regulatory approval and market expansion of ZYNLONTA.
• Patients: Potential for an improved treatment option for r/r DLBCL, offering longer PFS and higher CR rates.
• Healthcare Providers: May gain an additional therapeutic option to consider for their patients with r/r DLBCL.
• Regulatory Authorities (FDA): Will review the LOTIS-5 data for potential approval of ZYNLONTA in this indication.

Next Steps

• Conduct a pre-Supplemental Biologics License Application (sBLA) meeting with the U.S. FDA in August 2026.
• Prepare for a planned sBLA submission in the fourth quarter of 2026.
• Continue to evaluate a broad range of value maximizing alternatives, including near-term cost reduction initiatives.
• Present data from LOTIS-5 in Q4 2026.
• Seek compendia inclusion for ZYNLONTA in 1H27.
• Aim for confirmatory approval in 2H27.

Key Dates

Recommendation

While the trial met its primary endpoint and showed positive efficacy signals, the increased rates of serious adverse events and Grade 5 TEAEs, particularly in older patients, warrant careful consideration. The path to full regulatory approval and market adoption still involves significant hurdles and competition. Therefore, a 'hold' recommendation is prudent pending further regulatory review and market dynamics.

Keywords

ZYNLONTA, loncastuximab tesirine, ADC Therapeutics, DLBCL, relapsed refractory lymphoma, Phase 3 trial, LOTIS-5, hematology