CytomX Posts Interim Data From Phase 2 Trial Of CD71-Targeting Cancer Candidate

CytomX Therapeutics Inc CTMX announced preliminary Phase 2 results of CX-2029 in patients with either advanced squamous non-small cell lung cancer (sqNSCLC) or head and neck squamous cell carcinoma (HNSCC).

• The CD71-directed conditionally activated antibody-drug conjugate (ADC) is being co-developed by CytomX and AbbVie Inc ABBV.
• In the 16 efficacy, evaluable patients with sqNSCLC, the objective response rate (ORR) was 18.8%, including two confirmed partial responses (PRs) and one unconfirmed PR that was confirmed seven days after the data cutoff of October 29, 2021. 
• Two of these responses were ongoing, and the third had a response duration of 5.6 months. The disease control rate (DCR) was 87.5%. 
• In the 25 efficacy evaluable patients with HNSCC, there was one confirmed PR (ORR 4.0%) and a DCR of 56%, including one unconfirmed PR.
• The safety profile was consistent with the previous observations, with no new safety signals identified. 
• The most common treatment-related adverse events (TRAEs) were anemia, infusion-related reactions, fatigue & nausea, and decreased neutrophil count.
• Price Action: CTMX shares are down 23.4% at $4.94 during the premarket session on the last check Tuesday.