Pharmaceutical company Vertex, today released the results of a recent Phase 2b trial,
which looked at safety of a drug known as VX-661 in
combination with ivacaftor (Kalydeco). There has been a lot of anticipation
about these results because it is only the second time that the company has
issued trial data. Below,
This study involved 39
people with cystic fibrosis who have two copies of the F508del mutation, and confirmed
that the treatment is safe and well tolerated.
The stated improvement in lung function, from baseline, within four
weeks of treatment is also encouraging. It should be noted that the number of
people who took part in the study is extremely small. However the results
provide solid support for
the next stage of trials – Phase 3 – which Vertex commenced in the early part
of this year.
This program of four Phase 3 clinical trials will look at lung
function after the administration of the VX-661/ivacaftor combination, but this
time involves not only people with two copies of the
F508del mutation – who were studied in the phase 2b trial, and make up roughly
51% of the CF population – but also includes people who have one copy of the
F508del mutation and a second mutation that is either a gating mutation,
residual function mutation or a mutation that results in minimal CFTR function.
This will the first time
that the efficacy of this drug regime is being tested in a large population of people
with cystic fibrosis (approximately 1150, aged 12 and older). Furthermore, the
fact that 4 different ‘mutation combinations’ are being investigated, thus impacting
on a larger number of CF patients, means this next-stage trial is vital in
enhancing our knowledge-base in striving to reach our goal of beating CF for
good.
The Trust will be watching the Phase 3 trials with interest and ensure that our CF community remain updated on the progress in transformational treatments.
The Trust will be watching the Phase 3 trials with interest and ensure that our CF community remain updated on the progress in transformational treatments.
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Surely the improvement in FEV1 to 12 weeks (rather than just 4) is rather more relevant. While you can expect Vertex to emphasise the 4 week figures (because they are more flattering) I would expect greater objectivity from this review (especially as the relative improvement to 12 weeks when compared with the placebo group was even smaller).
ReplyDeleteHowever, as you say, this was a very small trial and any outliers would have had a disproportionate impact on the results (as happened in Vertex's similarly underpowered trial of ivacaftor monotherapy for pwcf heterozygous for the R117H mutation). It is good news that Vertex is proceeding with a Phase 3 trial which will yield more robust results.