Zai Lab (ZLAB) said Friday that updated data from a phase 1 study of zocilurtatug pelitecan, or zoci, showed a high response rate across all dose levels in heavily pre-treated patients with extensive-stage small cell lung cancer.

As a second-line treatment, zoci, formerly known as ZL-1310, demonstrated a 68% overall response rate in patients receiving 1.6 mg/kg, the company said.

Responses were also durable, with the estimated median duration of response at 6.1 months and median progression-free survival at 5.4 months across all doses, Zai Lab said.

The investigational drug also continues to show a well-tolerated safety profile, especially at the 1.2 or 1.6 mg/kg doses, the company said.

The company added that it has opened for patient enrollment the phase 3 registrational study of zoci, designed to further assess its safety and efficacy compared with investigator's choice single agent therapy in patients with relapsed small cell lung cancer.

Zai Lab shares were down nearly 2% in recent trading Friday.

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