Pfizer's personalised, novel drug Xalkori is now available in the UK for patients with non-small lung cancer who carry a specific protein known as ALK.

Xalkori (crizotinib) is a first-in-class, oral ALK inhibitor, which works by blocking signalling in various cell pathways believed to play a crucial role in the growth and survival of tumour cells.

The drug won a conditional licence in Europe in October for use in adults with previously treated ALK-positive advanced non-small-cell lung cancer (NSCLC), after data from early trials showed that it significantly improved progression-free survival in this subset of patients.

The primary endpoint in both studies was Objective Response Rate (ORR; defined as complete response plus partial response), and ORRs of 50% and 61% were seen in the Phase II and Phase I studies, respectively.

Describing the launch of Xalkori as "one of the most exciting breakthroughs" in cancer treatment in recent years, Professor Dean Fennell, from the University of Leicester, noted that it is the first treatment to target the ALK fusion protein specifically "and as a result, patients expressing this fusion protein have a good chance of response". 

As per the terms of a conditional approval, Pfixer will need to submit data from a confirmatory Phase III trial to regulators in order to gain a 'normal ' licence for the medicine.

'Superior' response

This trial showed that Xalkori provides "superior tumour response, progression-free survival and quality of life compared to standard practice of second line single agent chemotherapy," the company said.

Around 41,500 new cases of lung cancer are diagnosed in the UK every year; 85% of these are classed as NSCLC, and preliminary epidemiology suggests that around 3%-5% of NSCLC tumours are ALK-positive.

Cost regulators the National Institute for Health and Clinical Excellence and the Scottish Medicines Consortium will be appraising Xalkori next year, to determine whether the drug represents value for money for the National Health Service.