{
  "question_id": "W243",
  "slug": "alzheimers-drug-halves-decline",
  "title": "An Alzheimer's treatment that halves decline is approved",
  "type": "binary",
  "resolution": {
    "levels": [],
    "values": [],
    "annotations": []
  },
  "forecasts": [
    {
      "question_id": "W243",
      "forecast_date": "2026-09-20",
      "evidence_cutoff": "2026-09-20",
      "method": "wide-v2",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": "I include symptomatic cognitive treatments and treatment of biomarker-defined preclinical Alzheimer's disease if approved for an Alzheimer's indication, while requiring the specified primary clinical comparison and not merely biomarker clearance or associated-symptom relief.",
      "summary": null,
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-09-30",
          "p_yes": 0.001
        },
        {
          "period_end": "2026-12-31",
          "p_yes": 0.003
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.007
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.0149
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.0287
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.0481
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.0719
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.1044
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.1447
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.1875
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.2362
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.2935
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.3536
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.4085
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.4499
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.4857
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.5165
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.5431
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.566
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.5855
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.6021
        }
      ],
      "passes": []
    },
    {
      "question_id": "W243",
      "forecast_date": "2026-09-27",
      "evidence_cutoff": "2026-09-27",
      "method": "wide-v2",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": "I count cognition-enhancing symptomatic treatments and treatment of biomarker-confirmed preclinical Alzheimer's disease if the approved indication and pivotal primary clinical analysis meet the stated criteria; disease modification or symptomatic dementia at enrolment is not additionally required.",
      "summary": null,
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-09-30",
          "p_yes": 0.0002
        },
        {
          "period_end": "2026-12-31",
          "p_yes": 0.002
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.004
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.008
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.0149
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.0297
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.0491
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.0729
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.11
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.1589
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.2136
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.2765
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.338
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.3876
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.4305
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.4675
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.4995
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.527
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.5577
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.5865
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.6134
        }
      ],
      "passes": []
    },
    {
      "question_id": "W243",
      "forecast_date": "2026-10-02",
      "evidence_cutoff": "2026-10-02",
      "method": "wide-v2.1",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": "PACC5 (a cognitive composite) counts as a clinical cognitive scale; symptomatic drugs qualify when the drug arm improves and placebo declines; generic/bioequivalence approvals relying on decades-old trials are not counted (small residual allowance only).",
      "summary": null,
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-09-30",
          "p_yes": 0.003
        },
        {
          "period_end": "2026-12-31",
          "p_yes": 0.006
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.007
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.008
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.009
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.011
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.015
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.021
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.035
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.054
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.074
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.097
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.127
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.17
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.228
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.282
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.318
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.34
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.351
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.358
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.364
        }
      ],
      "passes": []
    },
    {
      "question_id": "W243",
      "forecast_date": "2026-10-09",
      "evidence_cutoff": "2026-10-09",
      "method": "wide-v2.1",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": null,
      "summary": "I put this at about 28% by the end of 2031. No approved Alzheimer's drug comes close: the best slow decline by about a fifth to a third. A qualifying approval most likely requires a large trial in people without symptoms, such as Lilly's donanemab study due in 2027 or Eisai's lecanemab study in early 2029, to roughly halve progression, then United States or European approval about a year later. The donanemab result in 2027 would most change this forecast.",
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-12-31",
          "p_yes": 0.001
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.002
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.003
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.004
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.007
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.016
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.033
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.058
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.086
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.112
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.135
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.155
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.177
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.2
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.224
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.242
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.258
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.267
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.275
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.28
        },
        {
          "period_end": "2031-12-31",
          "p_yes": 0.285
        }
      ],
      "passes": []
    },
    {
      "question_id": "W243",
      "forecast_date": "2026-10-16",
      "evidence_cutoff": "2026-10-16",
      "method": "wide-v2.1",
      "opened": "2026-09-16",
      "linked_questions": [],
      "reading_adopted": null,
      "summary": "The approved Alzheimer's drugs slow decline by about a quarter to a third, well short of half. The best chances come from large trials of amyloid-clearing antibodies, mainly in people who have amyloid but no symptoms yet. These trials report between late 2027 and 2029, so approvals could come from 2029. I put the chance at about one in four by the end of 2031. A very strong result from Lilly's donanemab prevention trial in late 2027 would raise this the most.",
      "ambiguities": [],
      "key_drivers": [],
      "would_update_on": [],
      "forecasts": [
        {
          "period_end": "2026-12-31",
          "p_yes": 0.002
        },
        {
          "period_end": "2027-03-31",
          "p_yes": 0.003
        },
        {
          "period_end": "2027-06-30",
          "p_yes": 0.004
        },
        {
          "period_end": "2027-09-30",
          "p_yes": 0.005
        },
        {
          "period_end": "2027-12-31",
          "p_yes": 0.007
        },
        {
          "period_end": "2028-03-31",
          "p_yes": 0.01
        },
        {
          "period_end": "2028-06-30",
          "p_yes": 0.016
        },
        {
          "period_end": "2028-09-30",
          "p_yes": 0.025
        },
        {
          "period_end": "2028-12-31",
          "p_yes": 0.04
        },
        {
          "period_end": "2029-03-31",
          "p_yes": 0.057
        },
        {
          "period_end": "2029-06-30",
          "p_yes": 0.085
        },
        {
          "period_end": "2029-09-30",
          "p_yes": 0.116
        },
        {
          "period_end": "2029-12-31",
          "p_yes": 0.14
        },
        {
          "period_end": "2030-03-31",
          "p_yes": 0.16
        },
        {
          "period_end": "2030-06-30",
          "p_yes": 0.19
        },
        {
          "period_end": "2030-09-30",
          "p_yes": 0.218
        },
        {
          "period_end": "2030-12-31",
          "p_yes": 0.234
        },
        {
          "period_end": "2031-03-31",
          "p_yes": 0.243
        },
        {
          "period_end": "2031-06-30",
          "p_yes": 0.25
        },
        {
          "period_end": "2031-09-30",
          "p_yes": 0.256
        },
        {
          "period_end": "2031-12-31",
          "p_yes": 0.262
        }
      ],
      "passes": []
    }
  ],
  "declined": []
}