Friday April 20 2012
The drug was only effective in difficult-to-treat asthmatics
UK scientists have created a “Drug that slashes the risk of colds killing asthmatics”, the Daily Express dramatically reported today.
This, and similar stories in the press about this “revolutionary treatment” for a very worrying scenario, should be viewed with a high degree of caution. The news is based solely on a press release, which gives some information about the findings of an early-stage clinical trial of a new, unlicensed asthma drug called SNG001. The press release describes research that was conducted in a total of 134 adults who had asthma and were suffering from the symptoms of the common cold. These asthmatic adults were given either SNG001 or an inactive treatment for two weeks.
Overall, SNG001 did not reduce the severity of asthma symptoms compared with the inactive “placebo” treatment. However, the researchers also looked only at people who had more severe asthma. They found that, for this group of people, SNG001 improved asthma symptoms and lung function over the two-week period compared with placebo. Although this group made up about half of the patients in the trial, only 10-20% of people in the UK population with asthma have severe asthma.
Limited conclusions can be drawn about the effects of this unlicensed drug at this stage. The study has not yet been fully published in a peer-reviewed journal and this means that full details are not yet available. SNG001 did not improve symptoms in all the participants who received the drug, only in those with more severe symptoms. Full publication of this trial, and further research in a larger group of people with asthma, will be needed to clarify whether this treatment is safe and effective. These findings do not alter the current treatment of asthma or respiratory infections.
Where did the story come from?
This story is based on a press release from Synairgen, a respiratory drug development company based at the University of Southampton. Synairgen has reported on the initial findings of a clinical trial involving a new asthma drug that they have been developing. The Synairgen website claims that the company raised £6 million to finance “two phase II proof of concept studies for its inhaled interferon beta programme” through the London Stock Exchange.
The study has not yet been published in a journal, so it has not been subjected to the peer-review process. As such, the findings reported should be treated with a high degree of caution. When reading stories in the press, it is always worth checking to see if they have quoted a peer-reviewed journal as the source of the research. To find out more about this and other tips on understanding health reporting, see How to read health news.
The Daily Mail and the Daily Express are premature in reporting the success of this new drug, and do not highlight the early stage of this research and the fact that the findings have not yet been formally published. The reports, which focus on the “life-threatening” nature of asthma, should be read in light of the fact that deaths from asthma are relatively rare. According to Asthma UK, 5.4 million people in the UK are being treated for the condition, and there were just 1,131 deaths from asthma in 2009. Also, the current study has only reported on the effects of the drug on outcomes such as symptoms of asthma and lung function, not on the risk of death.
What kind of research was this?
This phase II randomised controlled trial investigated whether the use of a new inhaled interferon beta drug (SNG001) could protect people with asthma against viral respiratory infections such as the common cold, which may worsen asthma symptoms.
Interferon is a drug that affects the body’s immune system. Injectable forms of interferon beta are currently licensed for the treatment of multiple sclerosis. Earlier laboratory research has discovered that cells lining the airways of people with asthma have weaker antiviral response to infection than similar cells in people without asthma. Researchers found that delivery of low levels of inhaled interferon beta could improve the antiviral response in the laboratory.
The earliest trial stage (phase I) for clinical trials is research conducted in a small group of people that looks at the safety of the drug and what is a safe dosage. Phase II clinical trials come next, looking at effectiveness and safety in a larger group of people with the condition, to see if it is worth taking the drug on to phase III trials. Phase III clinical trials are usually larger than phase II trials, and they are needed to show that the new drug is sufficiently effective and safe to be granted a licence to be sold to the public. If the results of the phase II trials are promising, SNG001 will still need to go through phase III trials to determine whether it can be licensed and used to treat patients outside of trials.
What did the research involve?
This phase II randomised controlled trial looked at 134 adults with mild-to-moderate to severe asthma, who had caught a cold. The researchers initially recruited 147 patients, but only 134 were confirmed to have a cold using a cold severity scale and laboratory identification of respiratory viruses on nasal and sputum samples. All patients were taking inhaled steroids, and all reported worsening asthma symptoms when they contracted the respiratory infection. Patients were randomised to receive either SNG001 or inactive placebo for 14 days.
Approximately half of the patients in the trial were reported to have “difficult-to-treat” asthma.
The researchers compared severity of the person’s asthma symptoms and the other asthma treatments required in the SNG001 and placebo groups. The results presented in the press release relate mainly to the first week of infection and treatment.
What were the basic results?
SNG001 did not improve asthma control (measured using the Asthma Control Questionnaire) in the overall treatment population compared with placebo, according to the Synairgen press release.
However, the researchers also carried out a “planned analysis” for the half of the trial population who had “difficult-to-treat” asthma. In these people who had “difficult-to-treat” asthma, SNG001 significantly improved asthma symptoms and lung function compared with placebo. The significant results for this “difficult to treat” category (who comprise 10-20% of people with asthma according to the press release) were as follows.
- SNG001 was reported to be well tolerated
- SNG001 prevented asthma symptoms from worsening during the first week of infection and treatment, as measured by the Asthma Control Questionnaire (p=0.004)
- 65% fewer patients taking SNG001 experienced moderate worsening of their asthma symptoms during the treatment period compared with those taking placebo (p=0.01)
- those taking SNG001 had less need to take inhaled bronchodilator medications (used to open the airways) on day five (p=0.02) and day six (p=0.01) than those taking placebo
- morning peak expiratory flow (the maximum amount of air breathed out as hard and fast as possible in a single breath) steadily improved in the SNG001 group across the treatment period, while in the placebo-treated patients there was an initial dip during the first week followed by an improvement (p=0.03)
How did the researchers interpret the results?
Professor Stephen Holgate CBE, leading international asthma specialist and founder of Synairgen, is quoted as saying: “This is a really promising breakthrough for the future treatment of asthma and one of the most exciting developments that I have seen in years.
“This is the first clinical study which appears to demonstrate that, by boosting the antiviral defences of the lungs of asthmatics rather than trying to inhibit rapidly evolving viruses, we can limit the adverse effects of viral infection significantly to prevent worsening of asthma symptoms in a high risk group of patients.
“Not only have we established the potential of SNG001 as a novel treatment for viral exacerbations in difficult to treat asthma but also a crucial link between viral infection, asthma symptoms and severity of disease.”
Limited conclusions can be drawn about this news story as it is based on a corporate press release. Full details of the research are not yet available and as the study has not yet been published in a peer-reviewed journal, it has not yet been subjected to an important quality-control process.
Despite the promising tone of the news stories and the press release, the trial’s primary endpoint (better control on the Asthma Control Questionnaire compared with placebo) was not achieved in the overall treatment population, according to the press release. Findings were only presented for the half of the patient population who were “difficult to treat” (precise patient number not given). This study has only tested the drug for two weeks in a small population group over a short period. The effects of repeated courses or longer-term use do not appear to have been studied yet. The effect of the drug on risk of death wasn’t reported in the press release, despite some papers suggesting that the drug can slash the risk of death from colds among asthmatics.
Full publication of this phase II trial is awaited. SNG001 – an inhaled beta interferon – is currently not licensed for use in asthma. Following on from this study, further phase III research in a larger group of people with asthma is likely to be needed to clarify whether this treatment is safe and effective, and to see who might gain most benefit from it. Positive results from such a study will be needed before this drug could be granted a licence for use in asthma patients.
These findings do not alter the current treatment of asthma or respiratory infections.
Analysis by Bazian. Edited by NHS Choices.