Zai Lab reveals early lung cancer data to challenge Amgen's Imdelltra

In an effort to compete with a newly approved Amgen medication, Zai Lab unveiled promising Phase 1a data for its drug candidate ZL-1310 on Thursday morning. The initial findings showed a strong response rate among patients with extensive-stage small cell lung cancer (ES-SCLC) who had previously undergone treatment. Specifically, 74% of the 19 patients treated with ZL-1310 experienced a positive response. These patients had previously received chemotherapy that included a platinum-based regimen.

Notably, patients with brain metastases also responded well to the treatment. All six patients in this subgroup achieved a partial response, which could set ZL-1310 apart from Amgen’s drug, Imdelltra. The latter's label excluded patients with brain metastases, a point highlighted by Jefferies analyst Michael Yee.

In terms of safety, the results for ZL-1310 were favorable when compared to Amgen’s trial data. ZL-1310 did not show any cases of cytokine release syndrome (CRS) or ICANS, a type of therapy-related toxicity, in its small sample size. In contrast, Amgen’s trial involving 99 patients indicated that 56% of Imdelltra recipients experienced CRS, and 7% had ICANS. At the approved dose, 51% of Imdelltra patients encountered CRS, with most cases being of low severity, according to Amgen.

The next logical step for Zai Lab is likely a Phase 2 study, which could serve as the basis for seeking accelerated approval, following the pathway taken by Amgen. However, Zai Lab has not yet disclosed a timeline for this upcoming trial.

Both ZL-1310 and Imdelltra target the delta-like ligand 3 (DLL3), but they function differently. Imdelltra is a bispecific T cell engager that also binds to CD3, while ZL-1310 is an antibody-drug conjugate that links an anti-DLL3 antibody to a topoisomerase 1 inhibitor.

Imdelltra received FDA approval in May, marking it as the first bispecific T cell engager approved for a major solid tumor such as ES-SCLC. Other companies, including Boehringer Ingelheim, are developing similar bispecific T cell engagers in early clinical stages. Additionally, Novartis and Legend Biotech are working together on a DLL3-targeted CAR-T cell therapy.

Zai Lab is also exploring the potential of ZL-1310 when used in combination with Roche’s Tecentriq, a well-known cancer immunotherapy drug. This combination could potentially enhance the efficacy of the treatment, offering hope for better outcomes in patients with ES-SCLC.