On August 26, FDA green-lighted Pfizer’s Xalkori to treat locally advanced and metastatic non-small-cell lung cancers that express an abnormal anaplastic lymphoma kinase (ALK) gene. The agency approved the drug along with a diagnostic test for the ALK gene abnormality, Abbott Molecular’s Vysis ALK Break Apart FISH Probe Kit. Up to 7% of those with NSCLC, typically patients without a history of smoking, have the gene abnormality.
Pfizer says the tyrosine kinase inhibitor will cost $9,600 a month or $115,000 for patients who take it for a year. In clinical trials, the average duration of treatment was between 22 and 32 weeks, but because the drug appears to extend patients lives, many may be on it for far longer than that.
The other drug-diagnostic approval was Roche’s Zelboraf to treat metastatic or unresectable melanoma and the Cobas 4800 BRAF V600 Mutation Test. Zelboraf, an oral kinase inhibitor, acts by blocking the function of the V600E-mutated BRAF protein. The mutation is present in about half the patients with late-stage melanomas.
The diagnostic will cost around $150 and the drug about $9,400 per month. It assumes, based on progression-free survival data from clinical studies, a treatment course of roughly 6–8 months.
In 2011, FDA sanctioned another drug for metastatic melanoma, Bristol-Myers Squibb’s Yervoy. This mAb therapeutic acts by binding to and blocking the actions of the cytotoxic T-lymphocyte antigen 4 (CTLA-4).
The antibody can cause significant side effects, however, including fatigue, diarrhea, skin rash, endocrine deficiencies, and colitis. Severe to fatal autoimmune reactions were seen in 12.9% of patients treated with Yervoy. When severe side effects occurred, Yervoy was stopped and corticosteroid treatment was started. Not all patients responded to this treatment. Patients who did respond in some cases did not see any improvement for several weeks.
Yervoy achieved sales of $121 million in the third quarter of 2011, with ISI Group analyst Mark Schoenebaum commenting that the number was $17 million above Wall Street projections. Bristol-Myers Squibb got Yervoy as part of its 2009 acquisition of Medarex.
Some analysts see obstacles ahead for Yervoy, which costs $120,000 for a full course of treatment, in the form of resistance from regulators overseas. Last October, the National Institute for Clinical Excellence recommended that at a cost of about £80,000, Yervoy “could not be considered a cost-effective use” of health funds. A final decision is expected after a public consultation.