Jazz Pharma’s SCLC drug fails to meet primary endpoint in combo trial

Jazz Pharmaceuticals and PharmaMar have revealed that their small cell lung cancer (SCLC) therapy lurbinectedin has failed to meet the primary endpoint in a phase 3 combo study.

The ATLANTIS trial evaluated lurbinectedin, which is already marketed in the US as Zepzelca, in combination with chemotherapy doxorubicin versus topotecan or cyclophosphamide/doxorubicin/vincristine (CAV) in adult SCLC patients whose disease had progressed following one prior platinum-based chemotherapy regimen.

While Jazz and PharmaMar announced that the study failed to meet the primary endpoint of overall survival in this population using the combination regimen, they added that key secondary and subgroup analyses ‘favoured’ the lurbinectedin combo arm.

The drug scored conditional approved as a monotherapy in the metastatic, second-line setting for SCLC by the US Food and Drug Administration (FDA) n June.

It won that approval based on prior phase 2 data, announced by PharmaMar at the 2019 American Society of Clinical Oncology congress, which had shown an overall response rate of 35.2% when the drug was administered as a second-line therapy.

In addition, patients treated with the combination therapy also demonstrated a progression-free survival of 4.6 months, with the company also reporting that those it deemed most sensitive to the drug had an ORR of 45%.

"Bringing Zepzelca to the US market earlier this year alongside our partner, PharmaMar, was an important advance for adults with metastatic SCLC, an aggressive disease with a historically poor prognosis," said Robert Iannone, executive vice president, research and development of Jazz Pharmaceuticals.

"While the combination of lurbinectedin and doxorubicin did not achieve the primary endpoint in this study, the overall results support the activity and tolerability of lurbinectedin in this line of therapy. We look forward to the further development of lurbinectedin in SCLC and other tumours, both as monotherapy and in combination,” he added.

Jazz and PharmaMar added in a statement that they would share the new ATLANTIS data with the FDA and work with the agency to determine what confirmatory data is needed for full approval.

Jazz licensed lurbinectedin from PharmaMar in December 2019, gaining exclusive rights to the drug in the US.

The Irish pharma company paid PharmaMar, which is based in Madrid, Spain, $200m for the drug, agreeing on further potential milestone payments of up to $250m, based on the achievement of accelerated and/or full regulatory approval of lurbinectedin by the FDA within certain timelines.