Recommendation The abstracts for the 50th meeting of the American Society of Haematology (ASH) have been made available online. The conference will run December 6-9 in San Francisco. The meeting will feature several presentations that shed further light on the safety and efficacy of omacetaxine in treating drug-resistant chronic myelogenous leukemia (CML). The most significant is Jorge Cortes’s update on the 202 study in T315I resistant CML patients. The new data at ASH 2008 strengthens our positive view on this compound for T315I-resistant disease and for patients failing two tyrosine kinase inhibitors (TKIs). No changes to 12mpt or BUY recommendation.
Key Points
We have obtained omacetaxine-related abstracts a fortnight ahead of the 50th ASH meeting, at which CXS’s drug omacetaxine mepesuccinate will feature. There are four studies of particular interest as they shed further light on the safety and efficacy of the drug and give more information about the expected market for this drug.
Two presentations will reveal excerpts from the 202 study, the registrationdirected Phase II/III trial of omacetaxine in CML patients who carry the T315I mutation, which makes their disease resistant to the standard of care (TKI drugs). Both studies confirm that haematologic and cytogenetic responses are being seen, albeit with different frequency and strength, in all stages of CML disease. The safety profile of the drug remains intact.
Evidence is emerging that the use of second generation TKI drugs as salvage therapies is not producing durable responses for many patients. This is significant for CXS because their 203 Phase II/III trial aims to get omacetaxine approved for patients who fail on two TKIs, whether they have the T315I mutation or not.
The use of second line TKIs is increasing as more CML patients become resistant to imatinib. Another study to be presented at ASH shows a higher than expected proportion of second TKI failures harbouring the T315I mutation as a new mutation. Forty-two percent of dasatinib failures and 10% of nilotinib relapses were due to T315I in patients with advanced disease. This is significant because CXS’s first marketing approval will focus on patients with the T315I mutation.
Read together, these studies increase our confidence in the models we’ve constructed to describe the emergence of omacetaxine into the CML market. The company remains on track to complete its New Drug Application (NDA) by mid-2009 and we expect the first launch to occur in 2010.
We make no changes to our CML models or valuation. We retain our price target of $1.50 per share and reiterate the BUY recommendation on CXS.
ASH 2008 - Preview
The abstracts for the 50th meeting of the American Society of Haematology (ASH) have been made available online. The conference will run December 6-9 in San Francisco. ASH is the premier annual conference for all haematologic malignancies. Although its focus is almost entirely on the science, it is watched closely by the investment community for new clinical progress. In recent years chronic myelogenous leukemia (CML) has featured prominently at ASH, given the success (both clinically and commercially) of tyrosine kinase inhibitors (TKIs). The CML sessions at ASH 2008 will again be dominated by TKIs such as imatinib (Gleevec, Novartis), dasatinib (Sprycel, BMS), nilotinib (Tasigna, Novartis) and bosutinib (Wyeth). Importantly for CXS, TKI-failure is also getting a considerable amount of attention this year, lead by omacetaxine. Two presentations will provide the Society with clinical updates on omacetaxine – looking at emerging results from CXS’s 202 study in T315I-resistant disease. This trial is a Phase II/III being conducted for a Subpart H Approval1 by the FDA and will support a New Drug Application (NDA) around mid-2009.
Other studies being released at ASH are of interest – an update on T315I prevalence in the CML population; and strong data that using alternative TKIs in patients who have already failed two different TKIs does not give durable responses. ASH 2008 looks positive for omacetaxine and CXS. We would expect CXS to release updates to the market soon after the completion of ASH 2008.
