UK biotech rockets up on Covid-19 'breakthrough' for inhaled interferon beta — can its small study live up to the boast?
Interferon beta, a cytokine approved and widely used in injectable forms, surfaced very early on as a potential treatment for Covid-19. A British biotech now says its inhaled formulation of the drug helped hospitalized patients recover — and lowered their risk of doing worse.
It’s a small study involving only 101 patients and missed some endpoints, but Synairgen said the results could signal a “major breakthrough.” If true, that would also mark serious validation for a drug that AstraZeneca once licensed but eventually abandoned as an asthma therapy.
First, the positives:
- Patients in the SNG001 arm saw their risk of requiring ventilation or dying reduced by 79% compared to those who received placebo, with a marginally positive p-value of 0.046.
- They were also “more than twice as likely to recover” — to the point where they can go about their daily lives despite the infection — although the difference here wasn’t spelled out (p=0.043).

Although the company didn’t use the exact wording, these outcomes appear to align with the primary endpoint listed on a trial posting, which measures clinical improvement during the 16-day dosing period on an 8-point scale. No further details on how patients improved or worsened along that scale were provided.
Shares shot up 173.97% upon the news, reaching 100 GBX on the London Stock Exchange.
One other secondary endpoint stood out, while others fell short.
Breathlessness, a severe symptom designed to be assessed alongside cough and sputum, was “markedly reduced” for patients who got the drug (p=0.007). The numbers for cough and sputum weren’t available.
Moreover, Synairgen noted, three participants died after being randomized to placebo, compared to zero deaths in the SNG001 group — not that they can draw any conclusion from it.
SNG001 works by sending high local concentrations of interferon beta, a “naturally occurring antiviral protein,” to restore the lung’s defense against the virus, according to Stephen Holgate, a University of Southampton professor who co-founded Synairgen.

But the trial, which was conducted across 9 sites in the UK, found that patients who already required oxygen at admission didn’t seem to benefit as much. The “numerical advantage” in the likelihood of hospital discharge didn’t translate to a statistically significant gain, with median time to discharge in the SNG001 group at 6 days and the placebo group, 9 days (p=0.096).
Synairgen also wanted to highlight that patients appeared to be more likely to have recovered by the end of treatment if they were on the drug, though it was again not statistically significant.
What does this all mean? The company is conducting further analysis and it has previously said a pivotal trial would be needed. Marsden said they are now working with regulators and other groups to “progress this potential COVID-19 treatment as rapidly as possible.”
It’s unclear how the data and those from a follow-up trial would be squared against interferon beta administered in more traditional, commercially available forms. These are being tested in combination with the HIV drug Kaletra in both the UK’s RECOVERY trial and the WHO-led SOLIDARITY study, two of the largest master protocols organized to weed out a roster of potential Covid-19 drugs.
A study out of Israel, published days ago, concluded that although interferon beta “did not change time to reach the clinical response, adding to the standard of care significantly increased discharge rate on day 14 and decreased 28-day mortality.”
Before the pandemic swept it up, Synairgen had been testing SNG001 in patients with chronic obstructive pulmonary disease. Back in 2014 AstraZeneca in-licensed the drug for asthma and kicked off a study, only to halt it early in 2016 after determining that an overall low number of exacerbations among the asthma patients recruited in that cold season would make it difficult to see if they could actually hit the primary endpoint that had been laid out.
“When we’ve collected cells from patients with COPD and asthma and older people…we find that their lung cells don’t respond very well to viruses,” Marsden told Endpoints News in a previous interview. “We have also along the way always recognized that with an emerging virus, the drug could be used.”
Whether it will be adopted is a whole other question likely won’t take long to answer in the frantic R&D race for treatments.
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