ADC Therapeutics SA — Form 6-K Summary
Reporting period: Form 6-K for June 2021, furnished June 22, 2021. The filing reports interim clinical results for camidanlumab tesirine (Cami) in relapsed or refractory Hodgkin lymphoma.
Business Context
ADC Therapeutics is a commercial-stage biotechnology company developing antibody-drug conjugates for hematologic malignancies and solid tumors. Its FDA-approved product is ZYNLONTA (loncastuximab tesirine-lpyl) for relapsed or refractory diffuse large B-cell lymphoma after at least two prior systemic therapies. Cami is an investigational CD25-directed antibody-drug conjugate.
Clinical and Other Key Metrics
- The pivotal Phase 2 Cami study enrolled 117 patients with relapsed or refractory Hodgkin lymphoma who had received at least three prior lines of treatment, or at least two lines if ineligible for HSCT.
- The interim analysis included 101 evaluable patients, with a median study duration of 5.1 months and a median of six prior systemic treatment lines.
- Overall response rate was 66.3% (67 of 101 patients); complete response rate was 27.7% and partial response rate was 38.6%.
- Median duration of response had not been reached.
- Nine of 117 patients, or 7.7%, proceeded to hematopoietic stem cell transplantation after Cami treatment.
- Grade 3 or higher treatment-emergent adverse events occurring in at least 5% of patients included hypophosphatemia, maculopapular rash, thrombocytopenia, anemia and lymphopenia.
- Seven of 117 patients, or 6.0%, developed Guillain-Barré syndrome or polyradiculopathy.
- The filing does not provide revenue, profit, cash flow, margins, debt, liquidity or other corporate financial metrics.
Material Changes and Management Commentary
The company reported updated interim Phase 2 results presented at the 16th Annual International Conference on Malignant Lymphoma. Management characterized the response rate and durability as encouraging in a heavily pretreated population and stated that the Phase 2 safety profile, including the incidence of Guillain-Barré syndrome, was consistent with Phase 1 results. No new safety signals were identified.
Outlook, Risks and Unusual Items
- The pivotal Phase 2 study is intended to support submission of a Biologics License Application; the filing does not state that a BLA has been submitted or approved.
- The study is ongoing, multicenter, open-label and single-arm, and the reported results are interim findings. Efficacy and safety outcomes may change with additional follow-up.
- Median duration of response had not been reached, so the eventual durability of responses remains uncertain.
- Guillain-Barré syndrome or polyradiculopathy occurred in 6.0% of enrolled patients and represents a material safety consideration.
- Cami is also being evaluated in a Phase 1b study as monotherapy and in combination with pembrolizumab for advanced solid tumors.
Investor Verification Checklist
- Verify subsequent Phase 2 data, final response rates and duration of response.
- Verify regulatory submissions, FDA interactions and any decision regarding a Cami BLA.
- Assess the incidence, severity, management and reversibility of Guillain-Barré syndrome or polyradiculopathy.
- Review the company’s financial statements separately for cash runway, operating losses, financing needs, debt and ZYNLONTA commercial performance.
- Confirm whether the interim findings were later modified by additional patient follow-up or safety reporting.