Clovis’ drug for advanced ovarian cancer given breakthrough status

Shares in the small pharma company Clovis Oncology climbed yesterday after the US FDA awarded its drug breakthrough status for treatment of advanced ovarian cancer.

Rucaparib is in the PARP inhibitor class of drugs, and is being developed for used as a monotherapy in patients who have received at least two lines of prior platinum-containing therapy, and who have BRCA- mutated tumours.

The drug is following hot on the heels of AstraZeneca's (AZ) rival PARP inhibitor, Lynparza (olaparib), which was approved by the FDA and EMA in December last year.

Clovis' drug could have a number of advantages over Lynparza; it will now be reviewed by the FDA for use after two lines of chemotherapy, rather than after three, for which AZ's drugs is approved.

Rucaparib is also being developed for two sub-types of patients with BRCA-mutated tumours – those with germline BRCA (gBRCA) and somatic BRCA (sBRCA) mutations. AZ's drug is only licensed for use in patient with gBRCA, which could provide another advantage for Clovis.

The Breakthrough Therapy designation was granted based on interim efficacy and safety results from two ongoing phase II studies of rucaparib in ovarian cancer, including a phase II study in women with gBRCA mutations, and the ARIEL2 treatment study.

A clinical data update from the ARIEL2 study presented last week showed that 70 per cent (16/23) of evaluable BRCA-mutant patients achieved a RECIST and/or CA-125 response, and 65 per cent (15/23) achieved a RECIST response. Responses were observed in both germline and somatic BRCA-mutant tumours.

The Breakthrough Designation is the company's second, it having gained the special status for its non-small cell lung cancer (NSCLC) treatment CO-1686 in May last year.

Coincidentally, Clovis is once again in competition with AZ in this area. AZ's AZD9291 was granted Breakthrough Therapy Designation for metastatic EGFR T790M mutation-positive NSCLC in April last year.

Clovis was set up in 2009 as an oncology specialist company and these molecules, along with a third molecule, lucitanib, could help it make its name in the cancer field.

Co-founder and chief executive Patrick Mahaffy has considerable experience in the field, having led companies such as Pharmion and NeXagen, and also previously headed private equity firm E M Warburg Pincus.

"It is a distinct achievement for a company our size to have been granted Breakthrough Therapy designation for two separate products under development, and especially in less than one year," he said.

"In the case of rucaparib, we believe it is in recognition of the encouraging response rate observed in women with BRCA-mutated advanced ovarian cancer treated with rucaparib, and this designation reinforces the unique profile of rucaparib among PARP inhibitors, as well as our leadership in the differentiated clinical development of a PARP inhibitor."

The company is aiming to demonstrate clinical value of rucaparib in advanced ovarian cancer patients whose tumours are not mutant BRCA, but whose tumours possess similar DNA repair deficiencies that behave like BRCA mutations.

Rucaparib is the only PARP inhibitor to have shown activity in this broader, but still selected, patient population, and analysts JP Morgan forecast the drug could earn $500 million-plus in peak sales.