Zymeworks' (ZYME) drug to treat certain reproductive tract cancers has shown promise in early testing, the biotechnology company reported Sunday at the European Society for Medical Oncology Gynaecological Cancers Congress.

The dose-escalation portion of an ongoing phase 1 study showed ZW191, an antibody-drug conjugate, achieved a 78.6% response rate in patients with high levels of the target protein, compared to 47.4% in patients with low or negative levels.

The results further support the potential of ZW191 to address limitations of currently available and investigational therapies and broaden treatment opportunities for patients with gynecologic cancers, said Zymeworks.