So far 4 cancers have occurred in #hemophilia patients who have undergone gene therapy with AAV vectors. Salivary gland cancer and ALL in the Biomarin trial, Hepatocellular Carcinoma in the UniQure trial and Tonsil cancer in a Baxter trial. 1/3
Investigations by the companies in each case concluded that the cancers were not related to the gene therapy. It would be good to also have an independent group that looks at the data and comments on any limitations, if present, in the certainty regarding lack of association. 2/3
I hope that every person with #hemophilia that undergoes gene therapy agrees to have their data submitted anonymously to the international database coordinated by the World Federation of Hemophilia. 3/3
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According to the article in @Nature on microclots and #longcovid the replication of the data is coming from a neuroscience group in Sheffield. I note this is unpublished work. This is an internationally important subject and I hope the authors submit a pre-print asap. 1/4
We need to see how reproducible the data are. The facts that the number of subjects studied are so small and also that they are finding the microclots in people who have not had #COVID19 are of significant concern. 2/4
I would like to see the correlation between the results of these microclot assays with the more traditional and well established assays of coagulation activation such as D-Dimer and Prothrombin fragment 1+2. 3/4
I joined the Biomarin conference this evening. Not much more info than the press release but here are a few snippets that I learned. 1/7
Biomarin phase 3 steroid use. Number of patients who needed steroids not mentioned. No mention of steroid adverse events. They said they just completed recruitment of a study that uses prophylactic steroids. 2/7
I believe that in #hemophilia gene therapy studies the adverse events due to steroids should be mentioned. These are high dose steroids for several weeks and adverse events are common. 3/7
Biomarin has just announced their year 2 phase 3 (134 patients) ValRox gene therapy in #hemophilia results. Yes on a Sunday evening! Stable and durable bleed control but the FVIII levels are falling significantly. tinyurl.com/2p92ksj8 1/4
Key questions: How many patients needed steroids, what was the variability in levels (and how many had levels <10% and <5%), how long is the response predicted to last? #hemophilia#genetherapy#ValRox 2/4
Considering the mean FVIII levels, it is not surprising that stable and durable annual bleed control was observed. I would expect not many patients in the <10% group. Loss of ABR control would only be expected when the levels fall below 10%. #hemophilia#genetherapy 3/4
What is the incidence of VITT after 2nd AZ vaccination? The MHRA are saying 1.3 per 1 million. I say it may be a lot less and could be zero. #VITT#COVIT19 1/7
We do not know much about the 2nd dose VITT cases that the MHRA claims to have had reported to them. They are all >50 but we do not know anything else. Why do they not publish type of thrombosis, age, sex, co-morbidities, anti-PF4? 2/7
It is accepted that the MHRA have had 18 reports of thrombosis with thrombocytopenia after 2nd dose AZ vaccine. But are they VITT? Do they definitely not have cancer or sepsis? Do they fulfil the attached typical VITT definition? 3/7
Health care workers and carers >18 years in the UK could get any vaccine relatively early on. Because of the Pfizer storage requirements, it was used largely in hospital vaccination sites. So in UK, hospital staff largely got Pfizer in contrast to Norway/Germany who got AZ. 1/4
In the UK this was a logistics issue since prior to March we knew nothing about VITT. Many European countries felt the efficacy data for the AZ vaccine were not strong for >65, so gave Pfizer to >65 and AZ to <65. 2/4
In Norway and Germany where the decision was to use AZ for <65 years, they also decided to give it to health care staff first. Since health care staff are more likely to be female, there was a large female excess in the persons who developed VITT. 3/4
What is the risk of vaccine-induced immune thrombocytopenia and thrombosis (VITT) after a 2nd AZ vaccine dose? This is the commonest question I get at present on twitter, email and in clinic. 1/6
The information released by the MHRA (the UK regulator) two days ago on their website stated that they have had 15 cases of 2nd dose VITT after 9 million 2nd doses of the AZ vacc administered (ie 1 VITT case every 600,000 2nd doses of the AZ vaccine). tinyurl.com/s53nf2w 2/6
If the rare of VITT in the UK after 2nd doses of the vaccine was the same as after the the 1st dose, we should have had (309-15)x9/23.9= 110.7 cases. According to the MHRA we have had 15 but expected 110. 3/6