A two-drug treatment left 79% of 83 treated patients with undetectable hepatitis D virus at 48 weeks, its maker says

The stories

12 on this beat today.

Every story told the same way: what happened, who is involved, why it matters, how it works, the truth and the good news.

1. 01

   A two-drug treatment left 79% of 83 treated patients with undetectable hepatitis D virus at 48 weeks, its maker says

   79% of 83

   treated patients with undetectable hepatitis D virus at week 48

   a company figure; the other 41 patients began treatment only at week 12 [1]

   44%

   of treated patients with undetectable virus and normal liver tests at week 48

   the trial's main goal, against none of the waiting group at week 12 [1]

   124

   patients in Vir's first final-stage hepatitis D trial

   two more final-stage trials report in early 2027 [1]

   10 of 10

   patients off treatment with undetectable virus at 12 weeks

   an early, exploratory look at an earlier trial [2]

   What happened

   • Vir Biotechnology, a US drug company, says its two-drug treatment for hepatitis D passed its first final-stage trial. [1]
   • Vir says 79% of the 83 treated patients had undetectable virus at week 48. [1]
   • The other 41 of the trial's 124 patients waited 12 weeks before starting treatment. [1] At week 12, none of those 41 had undetectable virus. [1]
   • These figures come from Vir's own news release. [1] No journal or regulator has reviewed them yet. [1]
   • Elebsiran is a short strand of RNA, the molecule that carries a gene's message. [1] It is designed to destroy hepatitis B's messages and so limit the protein. [1]
   • Tobevibart is a lab-made antibody, an immune protein. [1] It is designed to stop both viruses entering liver cells. [1]
   • Patients take the 2 drugs as separate injections once a month. [1]
   • The trial's main goal was harder: undetectable virus plus normal levels of ALT, a blood sign of liver damage. [1]
   • Vir says 44% of treated patients met that goal at week 48. [1] None of the waiting group had met it at week 12. [1]
   • Vir says 85% of 46 patients with cirrhosis, or badly scarred livers, reached undetectable virus. [1] Among 37 patients without cirrhosis, the figure was 73%. [1]
   • Vir reports all patients completed 48 weeks. [1] It reports one serious drug-related side effect: a fall in white blood cells that ended in 15 days. [1]
   • In a smaller, earlier trial, Vir says all 28 patients who reached week 96 had undetectable virus. [2]
   • Ten of those patients stopped treatment, and Vir says the virus stayed undetectable in all 10 at 12 weeks. [2]
   • Only 1 of the 10 has reached 48 weeks off treatment so far. [2] Vir calls this analysis early and exploratory. [2]

   Who is involved

   Hepatitis D is an infection of the liver, and Vir calls it the most severe form of long-term viral hepatitis. [1]

   The virus keeps copying itself only while a hepatitis B protein, called the surface antigen, is present, Vir says. [1]

   The release says the disease was recently classified as a cause of cancer. [1]

   • Elebsiran cuts a hepatitis B protein
   • Tobevibart an antibody that blocks entry
   • Vir Biotechnology a US company that makes drugs for infections and cancer; it ran the trial and released the results
   • Alnylam Pharmaceuticals a US gene-silencing drug company; it licensed elebsiran to Vir
   • People with hepatitis D people whose livers carry both hepatitis D and hepatitis B; 124 of them joined this trial
   • The FDA the US drug regulator; Vir plans to apply to it in mid-2027

   How it unfolded

   1. Week 96 virus undetectable
   2. Treatment stops 10 patients choose to stop
   3. 12 weeks later all 10 still undetectable
   4. Early 2027 two more final-stage trials are due to report [1]
   5. Mid-2027 Vir plans to apply to the FDA [1]
   6. Week 12 the waiting group starts treatment, none with undetectable virus [1]
   7. Week 48 79% of 83 treated patients have undetectable virus, Vir says [1]

   Why it matters

   If it holds up, people living with hepatitis D would have a monthly treatment that aims to clear the virus. [1]

   Vir says clearing the virus could lower the risk of cirrhosis, liver cancer and death from liver disease. [1] This trial has not shown that yet. [1]

   Vir's other final-stage trials include a comparison with bulevirtide, another hepatitis D drug. [1]

   How it works

   Virologists call hepatitis D a satellite virus: one that can copy itself only with help from another virus.

   Vir's 2 drugs target the hepatitis B protein, not hepatitis D's own genes. [1] They are designed so hepatitis D loses what it needs to spread. [1]

   Seen it before

   If you can only get into a club on a friend's pass, taking away the pass keeps you out.

   The truth

   • What is really going on Every result for Vir's hepatitis D treatment comes from Vir itself. [1][2]The final-stage figures are top-line numbers in a news release, and no journal or regulator has reviewed them. [1]
   • Why it works on people A single percentage with no comparison beside it, like 79%, reads as a finished answer before anyone asks what it was measured against.
   • The treated group was measured at week 48. [1] The waiting group was measured at week 12, so these two figures are not from the same time. [1]
   • Who gains Vir's investors — A success in the first of 3 final-stage trials supports the case for filing with the FDA in mid-2027. [1]
   • Who gains Alnylam Pharmaceuticals — It licensed elebsiran to Vir, so a sale would rest partly on its technology. [1]
   • Who pays People living with hepatitis D — They must wait for 2 more trials and a filing planned for mid-2027 before any regulator can decide. [1]
   • Nobody knows yet

     Whether hepatitis D stays gone after people stop Vir's treatment.

     Only 10 patients have stopped, and only 1 has been followed for 48 weeks. [2]

   • Nobody knows yet

     Whether clearing the virus prevents cirrhosis, liver cancer or death.

     Vir says it could, but the trial reports virus and liver-test results at 48 weeks, not those outcomes. [1]

   What comes next

   Vir has 2 more final-stage trials due to report in the first quarter of 2027. [1] It plans to apply to the FDA, the US drug regulator, in mid-2027. [1]

1. 02

   Community CPR training failed to lift survival

   What happened

   • A five-year US trial found that training whole communities did not help more people survive cardiac arrest. [4]
   • In a cardiac arrest the heart, breathing and pulse suddenly stop. [4] It is different from a heart attack. [4]
   • Starting in 2021, researchers randomly assigned 60 North Carolina counties, home to about 8.5 million people. [4]
   • In the chosen counties, emergency call handlers, first responders and residents were trained to act fast. [4]
   • In all, 22,459 adults had a cardiac arrest outside hospital. [4] Of those, 11,615 were in trained counties and 10,844 in the rest. [4]
   • The results came out on Sunday in the New England Journal of Medicine, a medical journal. [4]

   Who is involved

   • Call handlers spot an arrest
   • First responders use defibrillators
   • Residents learn CPR

   How it unfolded

   1. 2021 the trial starts
   2. Next at least another year of follow-up

   Why it matters

   About 350,000 people in the US have these arrests outside hospital each year. [4] Only 1 in 10 survives. [4]

   Survival chances fall by 10% with every minute that passes without CPR. [4]

   How it works

   Implementation science studies how care that works reaches people, and asks whether an idea failed or was never fully delivered.

   The trial trained almost 5% of people in those counties. [4] Denmark went from 20% in the early 2000s to 80% now. [4]

   Denmark makes people show a CPR certificate to get a driving licence. [4] Survival there is about 16%, against 10% in the US. [4]

   Seen it before

   A few pupils who know the fire drill cannot get a whole school out.

   The truth

   • What is really going on Separately, a five-year North Carolina trial that trained communities in CPR did not change survival, after training almost 5% of residents. [4]
   • The lead author, Carolina Malta Hansen, says bystander CPR appeared to rise in the trial's final year. [4] That came from an exploratory look at the data. [4]
   • Another cardiologist suggested that starting as Covid-19 emerged may have delayed the training's effect. [4]
   • Who pays People whose hearts stop in North Carolina — Their survival depends on someone nearby acting at once, and the trial reached few of the people nearby. [4]
   • Nobody knows yet

     How much more of North Carolina would have to be trained before survival changes.

     The trial reached almost 5% and Denmark reached 80%, and nothing in between has been tested here. [4]

   Good news

   • Denmark raised the share of its people trained in CPR from 20% in the early 2000s to 80%, and about 16% of people there survive a cardiac arrest outside hospital, against 10% in the US.

   What comes next

   The team will follow these counties for at least another year. [4]

2. 03

   A pressure pill may last after it stops

   What happened

   • A small study suggests a blood pressure pill may keep working long after some patients stop taking it. [5]
   • The pill, baxdrostat, suppresses aldosterone, a hormone that raises blood pressure. [5]
   • That condition is primary aldosteronism: small growths on the adrenal glands overproduce the hormone. [5] Its usual treatment is surgery to remove the affected gland. [5]
   • The study followed 14 patients who took the daily pill for 6 to 12 months and then stopped. [5]
   • Up to 2 years later, their blood pressure was still lower. [5]
   • Morris Brown of Queen Mary University of London led the study. [5] He says just under a quarter of patients came off all treatment. [5]

   Who is involved

   • Morris Brown study leader, London

   How it unfolded

   1. 6 to 12 months daily pill
   2. Pill stops patients stop taking it
   3. Up to 2 years later pressure still lower
   4. Now a larger trial is running
   5. Next year possible NHS use, if Nice agrees

   Why it matters

   The US approved baxdrostat earlier this year for high blood pressure that other drugs do not control. [5]

   In 5 to 10% of high blood pressure cases, this condition is the cause. [5]

   More than a billion people worldwide have high blood pressure. [5] Many who have this cause might avoid invasive tests and surgery if the effect lasts, a researcher said. [5]

   How it works

   Doctors call a disease that stays quiet with no drug in remission.

   Brown suspects that suppressing the hormone sets off a burst of reactive oxygen molecules. [5] He thinks those molecules kill the overactive cells. [5]

   Seen it before

   Pulling a weed out by its root keeps the bed clear after you stop weeding.

   The truth

   • Brown's explanation is still a hypothesis, and he says his team is testing it in the lab now. [5]
   • Mason Freeman of Harvard University worked on the study, published in the New England Journal of Medicine. [5] He said it is too early to say if anyone was cured. [5]
   • Nobody knows yet

     Whether any of baxdrostat's 14 patients was cured.

     A researcher on the study says it is too early to say, and a larger trial is still running. [5]

   Good news

   • In a study of 14 patients, just under a quarter came off all blood pressure treatment and had normal blood pressure, up to 2 years after they stopped the pill baxdrostat.

   What comes next

   A larger trial is under way. [5] England's drug-cost body, Nice, is assessing baxdrostat, which could reach the NHS next year. [5]

3. 04

   Pennsylvania reports sixth measles death

   What happened

   • Pennsylvania reported its sixth measles-linked death of the year on 4 November, an unvaccinated Jefferson County resident. [6]
   • Lancaster County had 3 of the deaths, Jefferson County 2 and Mifflin County 1. [6]
   • By 4 November the state had 1,467 confirmed cases, and 283 of those people had gone to hospital. [6]
   • Across the US, 4,852 confirmed cases had been counted by 29 October. [6]

   Why it matters

   The US has held measles-elimination status since 2000. [6]

   A Pan American Health Organization panel is expected to decide this week if the US keeps that status. [6]

   The US disease agency, the CDC, gave Pennsylvania nearly $4 million in emergency money to last through most of 2027. [6]

   How it works

   Epidemiologists say a country has eliminated measles when the virus no longer spreads continuously inside it.

   Pennsylvania's outbreak was still spreading in November and accounts for a substantial share of US cases. [6]

   The truth

   • The CDC lists 3 measles deaths this year, while Pennsylvania alone lists 6. [6]
   • The gap follows a policy change under Health Secretary Robert Kennedy Jr. [6] The CDC now counts these deaths from national mortality data. [6]
   • Who pays Pennsylvania's health department — Its federal emergency money is one-time funding, so the outbreak response depends on a sum that runs out during 2027. [6]
   • Nobody knows yet

     How many measles deaths the US has had this year.

     The CDC lists 3 while Pennsylvania alone lists 6, because the CDC now uses a different source. [6]

4. 05

   Semaglutide lowers pressure inside stiff hearts

   What happened

   • Semaglutide, a weekly obesity drug, lowered the pressure inside the heart in a year-long trial. [7]
   • The trial took 81 people with obesity and a stiff-heart form of heart failure. [7]
   • Researchers measured wedge pressure directly, during light exercise. [7] It shows how much blood is backing up in the heart. [7]
   • Over 52 weeks, that pressure fell 9.8 points on the drug and rose 0.9 on a dummy treatment. [7]
   • Normal pressure at rest and in exercise was reached by 53.7% on the drug and 7.4% on a dummy treatment. [7]
   • A scan study of 49 of those people found better work by the upper heart chamber. [8] The lower chamber filled more easily. [8]

   Why it matters

   Doctors already knew semaglutide eased symptoms in these patients, but not why. [7] This gives them a measured reason. [7]

   How it works

   Cardiologists call this heart failure with preserved ejection fraction: the heart pumps, but fills poorly, so pressure builds behind it.

   These patients started at 31.7 during light exercise, against 17.5 at rest. [7] Better filling on semaglutide went along with lower exercise pressure. [8]

   Seen it before

   A blocked sink fills up even when the tap runs slowly.

   The truth

   • The trial was small, and its main measure was pressure in the heart, not deaths or hospital stays. [7]
   • Nobody knows yet

     Whether semaglutide's lower heart pressure means fewer deaths.

     The 81-person trial was built to measure pressure in the heart. [7]

1. 06

   HIV antibody's protection fades, resistant strains follow

   What happened

   • An antibody meant to block HIV protected people at first, but resistant strains later got through, a new analysis found. [9]
   • The antibody, VRC01, is a lab-made immune protein given by drip into a vein. [9] It targets the place where HIV attaches to cells. [9]
   • Researchers studied two trials, in the Americas and sub-Saharan Africa. [9] They looked at weeks 80 to 104, after infusions had ended. [9]
   • Against highly sensitive HIV strains, overall protection was 66.3%. [9]
   • After infusions ended, HIV diagnoses and resistance were more frequent in the antibody groups than in the placebo groups. [9]

   How it unfolded

   1. Infusions antibody given repeatedly
   2. Weeks 80 to 104 what happened after
   3. During trial infusions given
   4. After the trial keep testing for HIV

   Why it matters

   The authors say several antibodies together are likely to be needed to stop this escape. [9]

   Such antibodies could matter most in places with high HIV spread, including parts of sub-Saharan Africa. [9]

   How it works

   Evolutionary biologists call this selective pressure: a drug removes the strains it can beat and leaves the rest. [9]

   As VRC01 levels fell, viruses held down during treatment appeared as infections, often more resistant. [9]

   Seen it before

   Checking only the easy-to-spot rule breakers leaves the sneakiest ones behind.

   Why one virus can infect people only with another virus's help

   Virologists call hepatitis D a satellite virus: it cannot spread without a protein from hepatitis B, so drugs can attack what it borrows.

   The twist

   A germ that has to borrow a part can be stopped by removing that part, even if the drug never touches the germ's own genes.

   The picture

   Hepatitis Bmakes the coat

   ↓→

   Hepatitis Dborrows the coat

   ↓→

   No coatcannot spread

   Step by step

   1. 1 Hepatitis B makes a coat protein
   2. 2 Hepatitis D borrows that protein to spread
   3. 3 A drug cuts the supply of the protein
   4. 4 Another drug blocks the way into liver cells
   5. 5 Hepatitis D has nothing left to borrow

   The same force, elsewhere today

   Where this chain is also running, in today's other stories.

   • Acorns predict Lyme risk two years out

     Young ticks need mice to survive, so the number of mice one year sets how many ticks can spread Lyme the next.

   • HIV antibody's protection fades, resistant strains follow

     HIV must attach at one spot on a cell, so an antibody at that spot blocks the strains that depend on it.

   Where you've seen this

   Parasitic plants

   mistletoe draws water from its host tree, so it dies if the branch is cut

   Phone apps

   an app built on another company's service stops the day that service closes

   Small shops in a mall

   a shop that relies on the big store's visitors loses them when that store shuts

   The catch

   Removing the borrowed part only works while it stays removed: Vir has followed its trial patients to week 48, and only 1 patient in its earlier trial has reached 48 weeks off treatment.

   And the whole of it

   An oak tree, a mouse and a tick all help decide whether a walker in New York gets Lyme disease, and none of them knows it. Most of us sit inside chains like that and only ever see the link next to us.

   What comes next

   The authors say future antibody trials need to test for the virus long after infusions end. [9]

1. 07

   Acorns predict Lyme risk two years out

   What happened

   • A 35-year study in New York State found acorn numbers predict Lyme disease risk. [10] Where deer were plentiful, a few more or fewer did not seem to change tick numbers. [10]
   • Lyme disease is an infection spread by the bite of black-legged ticks, often in their young nymph stage. [10]
   • When red oaks drop many acorns in autumn, more white-footed mice survive the winter. [10]
   • Tick larvae that feed on these mice are far more likely to survive to the nymph stage. [10]
   • The lead author, Richard Ostfeld, says the worst years can be predicted almost 2 years ahead. [10]
   • The research was published in the Proceedings of the National Academy of Sciences, a US science journal. [10]

   Why it matters

   A person's chance of Lyme infection depends largely on how many nymph ticks are near people outdoors. [10]

   How it works

   Disease ecologists call the mouse a reservoir host: an animal that keeps a germ going between human infections.

   White-footed mice infect the ticks that bite them very efficiently. [10] So more mice one year means more nymphs the next. [10]

   Seen it before

   More crumbs on the floor one week can mean more ants the next.

   Young ticks need mice to survive, so the number of mice one year sets how many ticks can spread Lyme the next.

   The idea, in story 06: Why one virus can infect people only with another virus's help →

   The truth

   • An outside researcher notes the study counted nymph ticks overall, not necessarily ones carrying the Lyme bacterium. [10]

   Good news

   • A 35-year study in New York State showed that acorn counts can warn of the worst years for Lyme disease almost 2 years ahead.
2. 08

   Keytruda's first copy faces a harder market

   What happened

   • The first publicly announced copy of Keytruda, the world's best-selling cancer drug, is under review at the FDA. [11]
   • The FDA accepted the application for the copy, FYB206, in October. [11] It could approve it as early as the third quarter of 2027. [11]
   • Keytruda brought Merck & Co $31.7 billion in 2025. [11] Its key patents begin to expire in 2028. [11]
   • A biosimilar is a close copy of a biological drug. [11] Makers must show it is as safe and effective as the original. [11]
   • About a dozen other copies of Keytruda are in development. [11]
   • The developers, Formycon and Zydus, say the FDA did not require a final-stage trial comparing it with Keytruda. [11]

   Who is involved

   • Formycon German developer of FYB206
   • Zydus partner selling it in the US and Canada

   How it unfolded

   1. October FDA accepts the application
   2. Third quarter 2027 earliest possible approval

   Why it matters

   Across all medicines, 118 biological drugs worth about $232 billion in possible sales could lose patent protection by 2034. [11]

   How it works

   Health economists call this a barrier to entry: something that keeps a cheaper rival off the shelf.

   Brand makers often strike deals with the middlemen who manage drug benefits. [11] Those deals can create financial reasons to stay with the original. [11]

   Seen it before

   A shop paid extra to stock one cola leaves little room for a cheaper one.

   The truth

   • Michael Abrams works for the firm Numerof & Associates. [11] He says most of these deals are too well hidden for anyone to evaluate. [11]
   • Who gains Makers of Keytruda copies — Formycon and Zydus say the FDA did not require a comparative final-stage trial, so they spent far less getting the drug ready. [11]
   • Who gains Drug-benefit middlemen — Deals with brand makers give them financial reasons to favour the original drug, a consultant says. [11]
   • Who pays Patients waiting for a cheaper Keytruda — Hidden deals can keep copies from taking sales even after approval, a consultant says. [11]
3. 09

   Merck stops its last IL-2 drug

   What happened

   • Merck & Co, a big US drugmaker, has stopped developing MK-1484, an experimental cancer drug. [12]
   • MK-1484 is built on IL-2, a natural signal protein that helps the immune system. [12]
   • The drug came from a 2018 deal with Sutro Biopharma and entered human tests in 2022. [12]
   • It was being tested alone and with Keytruda in advanced solid tumours, to find a dose for a later trial. [12]
   • Merck dropped its other IL-2 drug last year after early results showed no clear benefit. [12] It now lists no IL-2 drugs at all. [12]

   How it unfolded

   1. 2018 Merck and Sutro team up
   2. 2022 first human tests
   3. This week Merck confirms it has stopped

   Why it matters

   Bristol Myers Squibb also bet heavily on IL-2 through a deal with Nektar Therapeutics, and that deal ended badly. [12]

   How it works

   Immunologists call this kind of signal protein a cytokine: it tells immune cells to multiply and act.

   Several companies hoped IL-2 would make cancer immunotherapy work for more patients. [12] So far none has managed it, though Takeda and Innovent think they have found a way. [12]

   The truth

   • Merck called the decision "routine pipeline prioritization" and gave no more detail. [12]
   • Nobody knows yet

     Why Merck really stopped MK-1484.

     The company said only that it was routine pipeline prioritization. [12]

4. 10

   $455 million deal for a miniature heart pump

   What happened

   • Blackstone Life Sciences has signed a $455 million deal to co-fund a miniature heart pump. [13]
   • Boston Scientific, which makes medical devices, is developing the pump, called Vitalyst. [13]
   • The pump is meant to treat cardiogenic shock after a heart attack. [13] In that shock, the heart cannot pump enough blood to the brain and other organs. [13]
   • It is a temporary device placed across a heart valve, designed to increase the heart's output. [13]
   • This is the first time the two have co-funded a Boston Scientific product. [13] Blackstone made a similar deal with Medtronic in 2020. [13]

   Who is involved

   • Blackstone Life Sciences the investor
   • Boston Scientific the device maker

   How it unfolded

   1. 2020 Blackstone backs Medtronic diabetes work
   2. This month Blackstone backs Boston Scientific's pump

   Why it matters

   Cardiogenic shock still kills many patients despite advances in treatment. [13]

   The truth

   • Blackstone describes the pump's aims, not results: it is still being developed. [13]
   • Who gains Boston Scientific — Blackstone Life Sciences co-funds the pump's development, so Boston Scientific does not carry that cost alone. [13]
5. 11

   A gene test guided clot drugs in veterans

   What happened

   • A small study tested whether a gene test could improve the choice of anti-clotting drug in veterans. [14]
   • The 146 patients had undergone procedures to reopen narrowed leg arteries. [14]
   • Most took clopidogrel, a common pill that stops blood clots. [14] Variants of a gene called CYP2C19 may change how it works. [14]
   • In all, 61 patients had the gene test and 85 did not. [14]
   • Roughly a third of those tested were moved off clopidogrel. [14]
   • From 7 to 12 months, blocked blood flow hit 4.7% of tested patients and 21.3% of the others. [14]

   Why it matters

   People with narrowed leg arteries stay at risk of blocked blood flow after the procedure. [14]

   How it works

   Pharmacogenomics studies how a person's genes change the way a drug works in them.

   About a third of tested patients had their pill changed because of the result. [14] Blocked blood flow at 7 to 12 months was less common in that group. [14]

   Seen it before

   A charger fits only some phones, so you check the phone first.

   The truth

   • Across the whole study, major limb and heart events were 45.9% without the test and 32.8% with it. [14] That gap was not statistically clear. [14]
   • Most blockages in the tested group came in the first 90 days, and testing was found to be delayed. [14]
6. 12

   Family-doctor programme shows small gains in Germany

   What happened

   • A 12-year study in Germany found heart patients in a family-doctor programme did slightly better than those in usual care. [15]
   • Germany started the programme, known as HZV, in 2004 to strengthen family doctors' role. [15]
   • The study used insurance claims from 125,758 patients in 2011, rising to 169,101 in 2022. [15]
   • Compared with usual care, the odds of any hospital stay were 0.988. [15]
   • By the end of 2022, the odds of death from any cause were 0.987. [15]

   Why it matters

   Cardiovascular disease caused 32.7% of EU deaths in 2022 and costs 282 billion euros a year. [15]

   How it works

   Epidemiologists use an odds ratio to compare two groups: a value of one means no difference at all.

   Here the figures of 0.987 and 0.988 sit just below one, so the gap is real but very small. [15]

   Seen it before

   A team that wins a tiny bit more often over many seasons is better, but only just.

   The truth

   • The study only watched who joined the programme and did not assign anyone to it. [15]