The call from Bluebird was more introductory. They are continuing to expand trials and will be doing separate trials for beta zero patients than for beta+. Expect some changes in dosing, etc. I expect that they will continue to work on the vector, as well, just as SK has.
The link to the long term clinical trials is at
https://clinicaltrials.gov/ct2/show/NCT02633943?term=bluebird+bio&rank=1Here is the summary of SCD data from ASH 2015:
HGB-206 is an ongoing, open-label Phase 1 study designed to evaluate the safety and efficacy of LentiGlobin BB305 product candidate in the treatment of subjects with severe sickle cell disease (SCD). We recently announced the expansion of this study from eight subjects to 20 subjects, in order to collect more data and have flexibility on regulatory options and timelines. The study is evaluating safety and efficacy as measured by changes in red cell function tests and hemolysis markers, as well as clinical events secondary to SCD, including vaso-occlusive crises or acute chest syndrome events. As of November 17, we have manufactured drug product for four patients with severe SCD and three have been infused.
Drug product vector copy number (VCN) was 0.5/0.6 in Subject 1301, 1.3 in Subject 1303 and 0.6 in Subject 1306.
VCN in peripheral blood leukocytes at three months follow up was 0.04 in Subject 1301 and 0.11 in Subject 1303.
Early data on Subjects 1301 and 1303 with greater than three months of follow up, show a gradual increase in HbAT87Q levels:
At the six-month post-infusion follow up for Subject 1303, the proportion of anti-sickling hemoglobin accounted for 16 percent of all hemoglobin production (12 percent HbAT87Q + 4 percent HbF).
At the three-month post-infusion follow up for Subject 1301, the proportion of anti-sickling hemoglobin accounted for 17 percent of all hemoglobin production (4 percent HbAT87Q + 13 percent HbF).
Longer follow up data and additional subjects are required to determine the extent of HbAT87Q production and clinical impact of LentiGlobin BB305 in severe SCD.
The safety profile in the infused patients is consistent with autologous transplantation and no drug product-related grade >3 adverse events have been reported.