Clovis files key ovarian cancer drug in US

US biotech Clovis Oncology has filed its ovarian cancer drug rucaparib with the US regulator – a crucial development as this is now the only drug left in the company's pipeline.

Boulder, Colorado-based Clovis ended development of lung cancer rociletinib in May after advisers to the US regulator became concerned about its cardiac safety, at the same time axeing 35% of its workforce.

Earlier this month, the firm said it had also ended development of breast cancer drug lucitanib, taking a charge of $104.5 million in Q2.

Clovis is therefore relying solely on rucaparib, which the company has filed in patients with deleterious BRCA-mutated tumours, with both germline and BRCA mutations, after treatment with two or more chemotherapies.

But the news is better for rucaparib - the US Food and Drug Administration has assigned a faster, six month review period, with a decision due in February.

The most optimistic forecasts suggest peak sales of rucaparib at around $1 billion, although hopes were higher for rociletinib, which Goldman Sachs predicted would have peak sales of around $2 billion.

Foundation Medicines has also filed a companion diagnostic test that will test patients for eligibility for rucaparib.

Although the FDA has conditionally approved AstraZeneca's Lynparza (olaparib) in BRCA ovarian cancer, the regulator is thought to prefer Clovis' drug, granting it a breakthrough therapy designation last year.

Like rucaparib, AstraZeneca's drug is a poly ADP ribose polymerase (PARP) inhibitor, which was the first drug of this class to market following US approval in 2014.

Medivation, which was snapped up by Pfizer earlier this week, is also developing a PARP inhibitor, talazoparib, which is in late stage development in breast cancer with BRCA germline mutations.

The rucaparib filing contained data from 106 patients from two single-arm, open label clinical trials.

In study 1, limited to platinum sensitive patients, objective response rate was 60%, while in study 2, including platinum sensitive, platinum resistant and platinum refractory patients, the objective response rate was 50%.

Grade 3-4 treatment emergent adverse events reported in more than 10% of patients were anaemia/decreased or low haemoglobin, fatigue and increased alanine aminotransferase.