Registered forecast
84% registered probability event by 2026-10-26 Unresolved
FDA approves bepirovirsen for chronic hepatitis B on or before the disclosed PDUFA goal date of 2026-10-26
FF-007 Registered - Registered probability
- 84%
- Event by
- 2026-10-26
- Resolution window
- 2026-09-27 → 2026-10-26
- Target rung
- 5 Guideline
- 6 Regulatory
- 7 Coverage
- Baselines it has to beat
-
- Authority base rate 85%
- Calendar cycle 80%
- Analyst proxy 85%
nextconsensus.com/forecast/ff-007/ registry snapshot 2026-10-06 Share image
NextConsensus registered this probability on 2026-09-26. It is one of 14 registered FDA goal-date forecasts.
The proposition
What was claimed
The FDA takes an approval action on a New Drug Application for bepirovirsen (applicant GSK) for the treatment of chronic hepatitis B, with an approval action date on or before 2026-10-26, the PDUFA goal date disclosed in Ionis Pharmaceuticals' Form 10-Q filed 2026-07-29.
- Authority
- US Food and Drug Administration (FDA), Center for Drug Evaluation and Research (CDER) (US)
- Target rungA step on the 12-rung ladder: rungs 1 to 4 are the evidence moving, rungs 5 to 7 are a guideline body, regulator, or payer acting. The ladder, rung by rung
- Rung 6: Regulatory action — Label/indication change, approval action, REMS modification, or withdrawal by FDA, EMA, PMDA, Health Canada, etc.
- Forecast classThe group of like forecasts this one is counted and scored with, such as FDA actions by their goal dates
- FDA action by goal date
- Scope
- Chronic hepatitis B
The estimate
The number and the baselines it has to beat
The alternatives it was registered against, each with the reasoning that produced it.
ESTIMATE FROM THE SHAPE OF THE CLASS, NOT AN ENUMERATED COUNT. Original NDAs under Priority Review with positive randomised phase 3 trials are approved at their first goal date in a large majority of cases. The calendar's own met-goal-date share for disclosed PDUFA dates does not exist yet (docs/foundations/short-horizon-reference-classes.md §4.1); this is the honest state of the baseline at the cutoff.
A model that knows only the clock. The goal date falls inside the window; FDA meets the large majority of PDUFA goal dates; the share of first-cycle actions on original NDAs that are approvals is the rest. With no evidence input it cannot tell a strong application from a weak one.
A hepatology-focused analyst reading the same public record on 2026-09-22 — two positive phase 3 trials in NEJM, Breakthrough designation, Priority Review, approval in Japan a month earlier, a large sponsor — would call approval by the goal date likely, with manufacturing of a novel oligonucleotide as the main risk. Estimated by reconstructing that read, not by surveying analysts.
Regulatory action (FDA): offered on judgment, with no calibration figure until 15 in the class have resolved.
The clock
Dates that constrain the record
- Evidence cutoff
- 2026-09-26
Nothing after this date informed the estimate. - Registered
- 2026-09-26
Frozen and hashed. - Resolution window
- 2026-09-27 → 2026-10-26
When the adjudicator can read the outcome. - Event by
- 2026-10-26
The final qualifying action date; the frozen resolution rule defines what counts. Add to calendar
7a94b79fadc84e089049a64c530c032a32cfc876c966e1f24e37683f016a66e8 · operator record jc-1790461077721-b6900ecd
Around this record
- This kind of deadline
- Check it, follow it
Single-claim evaluation
Waiting on the FDA for an asset of your own?
Name the claim, who decides it, and the date your team commits to: a P&T meeting, an HTA submission, a label negotiation, a deal closing. Yours is registered under the same rules as the forecast on this page.
Resolution
The rule that settles the forecast
Resolves YES if the openFDA Drugs@FDA record returned by https://api.fda.gov/drug/drugsfda.json?search=openfda.generic_name:%22bepirovirsen%22 contains an application whose ORIG submission has submission_status AP and a submission_status_date on or before 2026-10-26, and the Drugs@FDA approval letter or label for that application names chronic hepatitis B in its indication. An approval for a narrower chronic hepatitis B population than the applicant sought still resolves YES. Resolves NO if no approval action is dated on or before 2026-10-26: a complete response letter, a goal-date extension, withdrawal or no action. The goal date is frozen as disclosed at the cutoff; a later extension does not move it, and an approval dated after 2026-10-26 resolves NO as occurred_after_deadline. Read no earlier than 2026-11-09. If openFDA has not refreshed by then, the Drugs@FDA web record (https://www.accessdata.fda.gov/scripts/cder/daf/, searched by the name bepirovirsen) governs. The application number was not public at the cutoff, so the rule reads by generic name; if the product carries a proprietary name, the generic name still identifies it. Resolves unresolvable only if neither source can be read after the read floor. Resolves VOID, with the reason recorded, only if FDA withdraws every public record of approval actions named above without an equivalent public successor, so that no approval date for this product can be read; while any of them publishes it, the rule stands.
Source the rule names: https://api.fda.gov/drug/drugsfda.json?search=openfda.generic_name:%22bepirovirsen%22, https://www.accessdata.fda.gov/scripts/cder/daf/
Readers: Resolver A, clinical methodology; Resolver B, payer evidence. The same two reader roles are assigned to every forecast registered so far.
What this record will show once it resolves
Beside every result, the count for its class (FDA action by goal date): registered, resolved, unresolved, and expired. One forecast is one instance, not a rate.
- The finding
- As the rule above reads it: occurred on time, did not occur, or left unscored.
- The readers and their sources
- Two reader roles read the source named above: Resolver A, clinical methodology; Resolver B, payer evidence. Who adjudicated it is named here, with the sources they read when the adjudication lists them. Being named as a reader means applying the frozen rule to the public record; it is not support for the estimate, the method, or NextConsensus.
- The number against its baselines
- 84% beside three baselines, each scored by the same rule (squared error), so a reader can see how the record did against each of them.
Reasoning
What the number rests on
The facts it was built from are below, as they stood at the cutoff, with every source archived; each baseline above carries the reasoning that produced it. The written mechanism and the conditions that would make the proposition ill-posed were frozen with the record and are held in the ledger, which the hash on this page covers.
Frozen covariatesThe facts about the evidence and the authority's process that were frozen with the forecast at its cutoff
The state of the record at the cutoff
Recorded as they stood on 2026-09-26, including the one field whose value was unknown then. It is left unknown rather than filled in.
- review pathway
- Priority Review (SRC-001); US Breakthrough Therapy and Fast Track designations (SRC-002)
- submission type
- original NDA; new molecular entity (antisense oligonucleotide)
- evidence class
- two randomised, double-blind, placebo-controlled phase 3 trials, B-Well 1 and B-Well 2 (SRC-002, SRC-003)
- pivotal n
- unknown — not stated in the archived sources
- endpoint type
- functional cure of chronic hepatitis B (HBsAg loss with HBV DNA suppression) as GSK describes it (SRC-003); the exact primary-endpoint wording is not in the archive
- approved competitors in class
- none — GSK describes it as the first functional cure approved (Japan, SRC-002)
- months since last guideline revision
- not applicable — no guideline is the subject of this proposition
- panel cycle position
- not applicable — the act is an FDA approval action
- sponsor request status
- filed Q1 2026 (SRC-003); accepted with Priority Review (SRC-001)
- odac referral
- none announced in the archived sources
- sponsor state change
- first global approval, Japan, 2026-08-24 (SRC-002)
Sources
Everything the estimate was built from
Each was retrieved on or before the 2026-09-26 cutoff and archived at the digest shown. If a publisher edits a page after the fact, the digest stops matching and the substitution is visible.
-
SRC-001Ionis Pharmaceuticals 10-Q for the quarter ended 2026-06-30, filed 2026-07-29. States that GSK is developing bepirovirsen for chronic hepatitis B and that the FDA granted Priority Review with a PDUFA action date of October 26, 2026. The disclosure is the licensor's; GSK is the applicant. -
SRC-002GSK plc 6-K dated 2026-08-24: Japan's MHLW approved Hibsago (bepirovirsen) for chronic hepatitis B, described as the first global approval. A regulatory decision in another jurisdiction; it says nothing about the FDA action. -
SRC-003GSK plc 6-K dated 2026-09-08 (results release): pipeline table lists bepirovirsen B-WELL 1/2 with 'Regulatory decision (US, JP)' still ahead, and states bepirovirsen was filed in Q1 2026.