Vir Hepatitis Delta Combo Meets Phase 3 Goal at 44%

Vir said on November 8, 2026 that its Phase 3 ECLIPSE 1 trial in hepatitis delta met its primary endpoint, with 44% of patients reaching the composite goal.

Last updated: November 9, 2026

Vir Biotechnology’s monthly combination of elebsiran and tobevibart met the primary endpoint of the pivotal ECLIPSE 1 trial: 44% of treated patients had undetectable hepatitis delta virus plus normal ALT at week 48, against 0% in the delayed treatment arm at week 12 (p<0.0001). Vir plans a US FDA submission in mid 2027.

Scope: this page covers news from Friday November 6 through Sunday November 8, 2026: the ECLIPSE 1 and SOLSTICE hepatitis delta data, the Natera leadership change and third quarter results, the Rhythm Pharmaceuticals tape, the autoimmune cell therapy datasets at ACR Convergence, Regeneron’s CIDEB siRNA liver data, and Friday’s market rebound.

What did Vir’s ECLIPSE 1 Phase 3 trial show in hepatitis delta?

ECLIPSE 1 met its primary endpoint. In 124 patients randomized 2:1, 44% of those on monthly subcutaneous elebsiran plus tobevibart reached undetectable hepatitis delta virus RNA together with normal ALT at week 48, against 0% in the delayed treatment arm at week 12, p<0.0001.

Elebsiran is a small interfering RNA that targets hepatitis B surface antigen production; tobevibart is a monoclonal antibody against hepatitis B surface antigen. Hepatitis delta virus can only replicate in people who also carry hepatitis B, which is why both drugs aim at the hepatitis B envelope. The trial enrolled a broad, multi country population that included patients with cirrhosis. The release was issued Sunday November 8 at 4:15 pm ET, after the topline was presented in an oral session at The Liver Meeting 2026 in Denver.

Endpoint (ECLIPSE 1)	Elebsiran + tobevibart, week 48 (n=83)	Delayed treatment, week 12 (n=41)
Primary: undetectable HDV RNA plus ALT normalization	44%	0%
Key secondary: undetectable HDV RNA	79%	0%
Virologic response (undetectable or at least 2 log10 drop)	100%	0%
ALT normalization	53%	5%
HBsAg below 10 IU/mL (exploratory)	95%	0%

Source: Vir Biotechnology release, November 8, 2026. P values below 0.0001 for the primary and key secondary endpoints. Note the comparison design: the treated arm is measured at week 48 and the delayed arm at week 12, when the delayed patients began treatment.

Did the combination work in patients with cirrhosis?

Yes, on the key secondary endpoint. Undetectable virus at week 48 was reached by 85% of patients with cirrhosis (n=46) and 73% of patients without cirrhosis (n=37), according to the release. The company did not break out the primary composite by cirrhosis status.

Cirrhosis matters commercially because hepatitis delta is the most aggressive form of viral hepatitis and a large share of diagnosed patients already have advanced liver disease. A regimen that suppresses virus at least as well in cirrhotic patients addresses the population most in need of treatment.

What was the safety profile of elebsiran and tobevibart?

Vir reported one Grade 3 treatment related adverse event, a decrease in neutrophil count that resolved in 15 days, and no treatment interruptions or discontinuations. Most treatment related events were mild to moderate and transient; the most common was flu like symptoms, mostly after the first dose.

The release does not give a count of serious adverse events. The full presentation and any publication will be the place to check that.

When will Vir file elebsiran and tobevibart with the FDA?

Vir plans a comprehensive global regulatory filing package with a US FDA submission in mid 2027. The release does not specify the application type. The combination holds FDA Breakthrough Therapy and Fast Track designations and EMA PRIME and orphan drug designations.

Milestone	Timing (per Vir)
ECLIPSE 1 topline (primary endpoint met)	November 8, 2026
Investor call on ECLIPSE 1 and SOLSTICE	Monday November 9, 2026, 8:30 am ET
ECLIPSE 2 data (patients not suppressed on bulevirtide)	Q1 2027
ECLIPSE 3 data (head to head vs bulevirtide)	Q1 2027
US FDA submission	Mid 2027

Outside the US, Vir licensed the program to Norgine in December 2025 for Europe, Australia and New Zealand, subject to marketing authorizations. ECLIPSE 3, a head to head comparison against bulevirtide in bulevirtide naive patients, is designed to support access and reimbursement.

What did the Phase 2 SOLSTICE data add?

Vir’s separate Sunday release (4:45 pm ET) reported that 100% of 28 SOLSTICE patients who completed week 96 had undetectable HDV RNA, and 89% (24 of 27) had improved or stable liver stiffness. In an exploratory finite treatment analysis, all 10 patients who stopped therapy reached SVR12, seven reached SVR24 and one reached SVR48, with no viral rebound or ALT flares reported.

The finite treatment data are interim, exploratory and based on 10 patients, as the company itself notes. They are a hypothesis, not a label claim.

Why did Natera stock fall after a strong third quarter?

Natera fell 14.6% on Friday November 6 to $310.67, our arithmetic from settled closes, after announcing on Thursday November 5 that Solomon Moshkevich, its President of Clinical Diagnostics, was appointed CEO effective immediately, and that Steve Chapman would step down and remain a consultant and board adviser. The same afternoon it reported a beat and raised guidance.

Natera Q3 2026 metric	Value	Change
Total revenue	$794.0 million	+34.1% vs $592.2 million
Tests processed	About 1,093,100	+22.3%
Oncology tests processed	About 339,500	+60.9%
Gross margin	64.7%	vs 64.9%
2026 revenue guidance	$3.005 to $3.035 billion	Raised from $2.850 to $2.910 billion
Cash, equivalents and restricted cash	About $1,097.2 million	At September 30, 2026

Source: Natera releases, November 5, 2026. MedTech Dive reported analysts at TD Cowen, BNP Paribas and Canaccord attributed the decline to the unexpected transition. The company gave no reason beyond Chapman’s statement that it was the right time for a transition. Moshkevich joined Natera in 2011.

What happened to Rhythm Pharmaceuticals stock on Friday?

Rhythm Pharmaceuticals closed at $112.28 on Friday, up 6.9% on the session and 29.9% above its $86.44 close before the first takeover report, our arithmetic. Neither Rhythm nor AstraZeneca has commented on the reported nonbinding approach.

The two reported constructions remain unreconciled: the Wall Street Journal reported $124 per share and Reuters reported as much as $134 per share including milestone payments. At Friday’s close the stock sat 10.4% below $124 and 19.3% below $134, our arithmetic. Automated trade items on Friday cited reports of a second bidder; we could not trace that report to a named outlet and do not treat it as established. We found no Rhythm release or filing dated November 6 to 8 on the $250 million credit facility draw the company had said it expected on November 6 (scope: searches Sunday night).

Which autoimmune cell therapy data came out at ACR Convergence 2026?

The weekend’s rheumatology releases centered on CD19 directed cell therapies and their competitors. CRISPR Therapeutics reported allogeneic data, Cabaletta Bio reported one year autologous durability, argenx reported Phase 3 myositis data for efgartigimod, and Johnson & Johnson reported Phase 3 psoriatic arthritis data for oral icotrokinra.

Company / asset	Modality	Headline data (per company release)	Next step
CRISPR Therapeutics, zugo-cel	Allogeneic CD19 CAR T	21 patients dosed; systemic sclerosis month 3 rCRISS-25 response 83% (5 of 6); all 9 myositis patients moderate or major TIS response; no CRS above Grade 2, no ICANS	Dose escalation ongoing
Cabaletta Bio, rese-cel	Autologous CD19 CAR T	Dermatomyositis 6 of 6 immunomodulator free TIS response through one year; lupus nephritis 5 of 5 DORIS remission	Myositis BLA planned 1Q 2028
argenx, efgartigimod (ALKIVIA)	FcRn antibody	Combined IMNM and DM primary endpoint met (TIS +15.4 points, p=0.0011); DM alone not significant (p=0.1093)	sBLA for IMNM by end 2026
Johnson & Johnson, icotrokinra (ICONIC-PsA 1)	Oral IL-23 receptor peptide	ACR20 58% vs 41% placebo at week 16 in biologic naive PsA	ICONIC-PsA 2 ongoing

Cabaletta’s safety pool of 71 patients showed no or Grade 1 CRS in 94% and no ICANS in 96%. CRISPR said six patients dosed at 200 million CAR positive cells showed higher expansion than at 100 million.

What did Regeneron’s CIDEB siRNA show in fatty liver disease?

In a first in human, placebo controlled study of a single subcutaneous dose in 40 adults with MASLD, Regeneron’s CIDEB siRNA reduced liver fat 58% to 80% by MRI at week 36, dose dependent, versus a 2.9% mean decrease on placebo, and normalized liver fat in 62% of treated patients. The data were presented at The Liver Meeting and published in NEJM.

CIDEB is a gene where loss of function variants are associated with protection from liver disease, which makes it a genetics validated target. Phase 2a, 2b and 3 trials are recruiting, and Regeneron hosts a MASH pipeline investor event on Tuesday November 10 at 8:30 am ET.

What else did Johnson & Johnson report over the weekend?

At SITC 2026, J&J reported a 73% PSA50 response rate (11 of 15) for pasritamig plus JNJ-9401 at the recommended regimen in heavily pretreated metastatic castration resistant prostate cancer, with no Grade 3 or higher treatment related adverse events; the company called the findings preliminary. Friday was also the first reaction session for Thursday evening’s Rybrevant Faspro approval: J&J closed at $276.22, up 1.4%.

How did biotech stocks trade on Friday November 6?

The SPDR S&P Biotech ETF rebounded 2.6% to 152.21 after Thursday’s 6.7% drop, while the S&P 500 ETF rose 0.3%. The movers that carried a story are below; all closes are settled exchange closes and all percentages are our arithmetic versus Thursday November 5.

Ticker	Close Nov 6	Change	Context
NTRA	$310.67	−14.6%	Unexpected CEO transition alongside a guidance raise
RYTM	$112.28	+6.9%	Reported AstraZeneca approach; no company comment
VIR	$12.21	+10.8%	Before the Sunday ECLIPSE 1 release; Monday is the first reaction session
JNJ	$276.22	+1.4%	First session after the Rybrevant Faspro approval
KPTI	$0.0549	−8.7%	Nasdaq suspension at the open Wednesday November 11
XBI / SPY	152.21 / 735.29	+2.6% / +0.3%	Partial rebound after Thursday’s AI driven selloff

Frequently asked questions

What is hepatitis delta?

Hepatitis delta is a liver infection caused by hepatitis delta virus, which can only replicate in people who also have hepatitis B. It is considered the most severe form of chronic viral hepatitis.

What drugs were tested in ECLIPSE 1?

ECLIPSE 1 tested Vir Biotechnology’s elebsiran, a small interfering RNA, combined with tobevibart, a monoclonal antibody, both given subcutaneously once a month.

What was the ECLIPSE 1 primary endpoint result?

44% of treated patients had undetectable HDV RNA plus normal ALT at week 48, versus 0% in the delayed treatment arm at week 12, p<0.0001.

How many patients reached undetectable virus in ECLIPSE 1?

79% of treated patients reached undetectable HDV RNA at week 48, including 85% of patients with cirrhosis and 73% without.

How many patients were in ECLIPSE 1?

124 patients were randomized 2:1, 83 to immediate treatment and 41 to delayed treatment starting at week 12.

When will Vir submit elebsiran and tobevibart to the FDA?

Vir plans a US FDA submission in mid 2027 as part of a global regulatory filing package.

When do ECLIPSE 2 and ECLIPSE 3 read out?

Vir expects data from both trials in the first quarter of 2027. ECLIPSE 3 compares the combination head to head with bulevirtide.

Is finite treatment possible with elebsiran and tobevibart?

It is an open question. In an exploratory SOLSTICE analysis of 10 patients who stopped therapy, all reached SVR12 and seven reached SVR24, but the company describes these data as interim and exploratory.

Who is Natera’s new CEO?

Solomon Moshkevich, previously President of Clinical Diagnostics, became Natera’s CEO effective November 5, 2026. Steve Chapman stepped down and remains a consultant and board adviser.

What was Natera’s third quarter 2026 revenue?

Natera reported third quarter revenue of $794.0 million, up 34.1%, and raised 2026 revenue guidance to $3.005 to $3.035 billion.

Has AstraZeneca made a formal offer for Rhythm Pharmaceuticals?

No offer has been confirmed by either company. The Wall Street Journal and Reuters have reported a nonbinding approach at $124 per share and up to $134 including milestones, respectively.

What is zugo-cel?

Zugocabtagene geleucel is CRISPR Therapeutics’ allogeneic, off the shelf CD19 CAR T therapy, in a Phase 1 basket trial in lupus, systemic sclerosis and inflammatory myositis.

What is CIDEB siRNA?

It is Regeneron’s investigational small interfering RNA that silences the CIDEB gene in the liver. A single dose cut liver fat 58% to 80% at week 36 in a Phase 1/2 study.

Sources

Primary: Vir Biotechnology, “Vir Biotechnology Announces Primary Endpoint Met in Pivotal Phase 3 ECLIPSE 1 Trial for Elebsiran and Tobevibart in Chronic Hepatitis Delta,” Business Wire, November 8, 2026. Vir Biotechnology, expanded Phase 2 SOLSTICE data release, Business Wire, November 8, 2026. Natera, “Natera Reports Third Quarter 2026 Financial Results” and “Natera Announces Leadership Transition,” Business Wire, November 5, 2026. CRISPR Therapeutics, zugo-cel update, GlobeNewswire, November 8, 2026. Cabaletta Bio, rese-cel ACR Convergence release, GlobeNewswire, November 8, 2026. argenx, ALKIVIA release, November 7, 2026. Johnson & Johnson, ICONIC-PsA 1 release, PR Newswire, November 7, 2026, and pasritamig SITC release, PR Newswire, November 8, 2026. Regeneron, CIDEB siRNA release, GlobeNewswire, November 8, 2026.

Trade press (attributed): MedTech Dive, Natera CEO coverage, November 6, 2026. Reuters and the Wall Street Journal, Rhythm and AstraZeneca reporting, November 4 and 5, 2026.

Market data: settled exchange closes for November 5 and 6, 2026; percentage changes are BioMed Nexus arithmetic.