Q: In March 2016, we published your blog about how to initiate therapy for an adult patient newly diagnosed with chronic myeloid leukemia (CML). As of July 2017, what, if anything, has changed?
A: Two words: Generic imatinib.
The National Comprehensive Cancer Network (NCCN) and its European counterpart, the European Leukemia Network (ELN) are both agnostic in regards to the initial tyrosine kinase inhibitor (TKI) treatment of choice for chronic phase CML. To review, the more potent “second generation” TKIs (dasatinib and nilotinib) have, compared to the “first generation” TKI imatinib, more efficacy in regards to a lower rate of progression to blast crisis, and deeper molecular responses. Imatinib appears to have a safer long-term toxicity profile, especially in regards to cardiovascular issues. TKI therapy has allowed CML patients to have a near normal life expectancy, and randomized trials show no survival advantage of one TKI over another. When the second generation TKIs were approved, they were considerably more expensive than imatinib, but by way of some imaginative marketing feats, branded imatinib prescription costs rose to similar levels as the newer TKIs (~$140.000/year). Thus, there is no obvious cost advantage for prescribing the old, reliable imatinib. (Imagine this happening in the auto industry. The 2018 models come out, and last year’s price for the 2017 model suddenly rises to the 2018 version level. Who would buy the outdated model?)
However, in 2016 a generic version of imatinib became available. Costs of this generic were initially very similar to the branded drug, but a second generic was introduced, and costs have predictably begun to fall. A quick internet search finds that branded imatinib will cost roughly $11,000/month, whereas generic imatinib runs from $6-10,000/month. Experience with other generics suggest that these costs should further plummet with the introduction of more generics. In the meantime, you can send your patient to Canada ($9,000/year) or, if more adventuresome, India ($400/year). The extra savings should cover business class flight and a number of fine hotel stays.
The goals of CML treatment are
- prevent progression to blast phase (since therapy efficacy has not progressed in decades)
- minimize toxicity
- in the appropriate patients, get a deep molecular response, as some patients with a deep and lasting molecular response can have their TKI discontinued, and not relapse
Considerations in this latter group are younger patients (especially if they wish to have children), and those patients who actually will consider discontinuation (some don’t if they have had a great response to therapy). Thus, in patients with high-risk chronic phase CML (by Sokal, Hasford, or EUTOS clinical score), or young patients wishing the option of possible discontinuation, the second generation TKIs are a fine choice. For patients with low-risk disease, older, and/or adverse co-morbidities (particularly cardiovascular) imatinib is a solid pick. The availability of generic imatinib makes this an even more attractive option for the majority of newly diagnosed cases.
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