AbbVie’s experimental PARP inhibitor veliparib has failed to meet key targets in two late-stage studies testing its potential in lung and breast cancer.

The studies were assessing veliparib in combination with the chemotherapy regimen carboplatin and paclitaxel in patients with squamous non-small cell lung cancer (NSCLC) and triple negative breast cancer (TNBC).

In the lung cancer trial, the primary endpoint was was improvement in overall survival in a group of patients who had smoked within the past 12 months and had more than 100 smoking events in their lifetime.

Secondary endpoints included improvement in overall survival in the intent-to-treat population, as well as progression-free survival and overall response in the primary endpoint subgroup and in the intent-to-treat population.

In the breast cancer study, the primary endpoint was complete pathologic response to treatment, while secondary endpoints included breast conservation rate, overall survival and event-free survival.

"Research shows there is a role for PARP inhibitors in cancers associated with DNA repair deficits, such as those with BRCA mutations. In these clinical trials, we wanted to explore whether a PARP inhibitor could augment chemotherapy in patients with squamous non-small cell lung cancer and triple negative breast cancer by disrupting the repair of cancer cells," said Gary Gordon, vice president, oncology clinical development, AbbVie.

"Unfortunately, these data do not support the use of veliparib in combination with chemotherapy in these patients."

More specific details will be unveiled at upcoming medical meetings or published in a peer-reviewed journal, the firm noted.

Currently approved PARP inhibitors include AstraZeneca’s Lynparza (olaparib), Tesaro's Zejula (niraparib) and Clovis’ Rubraca (rucaparib), all as treatments for ovarian cancer.