Weapon Against Alzheimer’s Just Got FDA-Approved — Transcript

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1. 0:00The results hit like a ton of bricks and
2. 0:01have got critical implications for the
3. 0:03recently FDA approved Alzheimer's blood
4. 0:05test. So researchers were packed to the
5. 0:07wall at a conference in San Diego last
6. 0:09month. They were there to hear some of
7. 0:11the most highly anticipated results in
8. 0:13Alzheimer's research for years. So the
9. 0:15results were from the Evoke and Evoke
10. 0:17Plus trials which have been testing the
11. 0:19impact of GLP-1 medications on patients
12. 0:21with earlystage Alzheimer's. So GLP-1
13. 0:24medications have been a wonder drug.
14. 0:25They've been a gamecher for treating
15. 0:27diabetes and then they revolutionized
16. 0:29weight loss medicine and we had good
17. 0:31reason to think that there might be a
18. 0:32powerful defense against dementia. But
19. 0:35then the numbers went up on screen. It
20. 0:37was a total failure. The daily dose of
21. 0:39simaglutide did nothing to delay
22. 0:41Alzheimer's progression. There's been
23. 0:42failure after failure of treatments for
24. 0:44dementia and now another one. But here's
25. 0:46the problem. It's possible that we're
26. 0:48getting nowhere because we're detecting
27. 0:50Alzheimer's disease too late. And by the
28. 0:52time that we know it's there, it's
29. 0:53already silently wrecked havoc on the
30. 0:55brain tissue for years. So more than
31. 0:57anything else, what we need is a
32. 0:58reliable way to find it early when
33. 1:00there's time to still do something about
34. 1:02it. And with a fresh FDA approval of a
35. 1:05simple blood test, we might finally have
36. 1:06it. But there's reason to be cautious
37. 1:08because we've been here before. So for
38. 1:10most of the 100-year history of
39. 1:12Alzheimer's disease, the only way that
40. 1:13we knew for sure that a person had it
41. 1:15was to wait until they died and examined
42. 1:17their brain. That began to change though
43. 1:19in the 1990s. By then we had a better
44. 1:21understanding of the disease progression
45. 1:23and researchers had identified
46. 1:25particular proteins and protein
47. 1:26fragments that were characteristic of
48. 1:28the condition. So they had an idea
49. 1:30perhaps we could look at samples of the
50. 1:32fluid surrounding the spinal cord and
51. 1:33brain and look for clues about the
52. 1:35activity of these key proteins. So
53. 1:37unlike blood which has to pass through
54. 1:39the bloodb brain barrier this fluid is
55. 1:41in direct contact with the brain. So
56. 1:43it's a bit like going through someone's
57. 1:44trash to search for clues about their
58. 1:46financial situation. So soon a
59. 1:48breakthrough came. Scientists found that
60. 1:50markers in the cerebral spinal fluid
61. 1:52tracked tightly with Alzheimer's disease
62. 1:54diagnoses. So one of them for example
63. 1:56was beta amaloid 42. The levels were
64. 1:59significantly lower in patients with
65. 2:00Alzheimer's. And based on these kinds of
66. 2:02discoveries, tests of the cerebrros
67. 2:04spinal fluid which is drawn from the
68. 2:06lower back had been developed and they
69. 2:08had been used extensively in studies of
70. 2:10Alzheimer's. But they're still primarily
71. 2:12used as a research tool. They're not
72. 2:13really used in clinical medicine. So,
73. 2:15other diagnostic tools like PET scans
74. 2:17are great because they've finally given
75. 2:19us a way to detect physical changes in
76. 2:20the brain caused by Alzheimer's disease,
77. 2:23but there are drawbacks to these
78. 2:24approaches. They can be expensive and
79. 2:26they aren't necessarily accessible to
80. 2:28all patients. And that wasn't actually a
81. 2:30huge issue until recently because there
82. 2:32wasn't really much that we could do even
83. 2:33if we knew that the disease was present
84. 2:35or about to come on. But now that we've
85. 2:37got approved medications that can slow
86. 2:39down disease progression, there's a
87. 2:40sudden pressure on doctors to find ways
88. 2:43to give their patients a clear answer
89. 2:44about whether they've got the disease
90. 2:46sooner rather than later. What we've
91. 2:48been needing is a simple, cheap tool to
92. 2:50put effective diagnosis in the hands of
93. 2:52clinicians. And it looked like it
94. 2:54finally arrived in 2023. So midway
95. 2:57through that year, Quest Diagnostics
96. 2:59announced that it would start offering
97. 3:00an Alzheimer's blood test directly to
98. 3:02consumers through its clinics. So the
99. 3:04test was built on the common but now
100. 3:06possibly debunked theory that amaloid
101. 3:08plaque formation is a central driver of
102. 3:10Alzheimer's disease progression. So the
103. 3:11logic does make sense. But it is worth
104. 3:13noting that researchers are increasingly
105. 3:15concerned about amaloid plaque formation
106. 3:17that it might not be as important as
107. 3:19what was once thought. But how well did
108. 3:21this blood test actually work? Well,
109. 3:22there was some early data presented at a
110. 3:24conference where it showed a group of
111. 3:26209 people and the test reported to have
112. 3:29a sensitivity of 89%. So that would mean
113. 3:32out of 100 people who actually had
114. 3:33Alzheimer's, the test would correctly
115. 3:35flag 89 as positive. The specificity
116. 3:38though was 71%. So that meant that for
117. 3:41100 people without the disease who were
118. 3:43tested, 29 would get a false positive
119. 3:46result. So critics were quick to raise
120. 3:48their worries. These numbers were simply
121. 3:49not good enough that would lead to mass
122. 3:51quantities of false diagnosis. The worry
123. 3:53was that with such high numbers of false
124. 3:55positives, it would spike demand for
125. 3:57follow-up testing and for services from
126. 3:58dementia focused clinics that wouldn't
127. 4:00actually give any benefits. This would
128. 4:02overwhelm capacity and divert resources
129. 4:04from those who truly needed care. Not to
130. 4:06mention the psychological impact of
131. 4:08false diagnosis. So, the test was not
132. 4:10approved by the FDA, but it didn't need
133. 4:12to be in order to be marketed to
134. 4:14consumers. But the chorus of concerns
135. 4:16raised by the medical community, it
136. 4:18prevented this test from gaining
137. 4:19traction with doctors. So, that's what
138. 4:21makes this recent FDA approval so
139. 4:23exciting because it looks like we
140. 4:25finally have the type of simple,
141. 4:27accurate test that we've been waiting
142. 4:28for. But there's also an important
143. 4:30downside which we'll see shortly. So,
144. 4:31the test looks at levels of PTA 181 in
145. 4:34the blood. This test is designed to be
146. 4:36used who are aged 55 and older who are
147. 4:39showing some early signs of cognitive
148. 4:40decline. So, PTA 181, it's a protein
149. 4:43that's been widely studied as a reliable
150. 4:45biomarker to signal the presence of
151. 4:47Alzheimer's. But how effective is this
152. 4:49new blood test? Well, here's where
153. 4:51things get a bit tricky. So, the test is
154. 4:53intended to rule out Alzheimer's, not
155. 4:55rule it in. So, in other words, it tells
156. 4:57you if you don't have the disease. It's
157. 4:59not designed to tell you if you do. So,
158. 5:00it's very good at the job that it's
159. 5:02intended for. So, in a clinical trial,
160. 5:04the probability that a person with a
161. 5:05negative result truly doesn't have the
162. 5:07disease was 98%. So, if we see a
163. 5:10negative result on the test, we're
164. 5:12probably in the clear. But what about a
165. 5:13positive result? What does that mean?
166. 5:15Well, unfortunately, it still leaves us
167. 5:17with a lot of questions. In that same
168. 5:19trial, the odds of a positive result
169. 5:21that meant Alzheimer's was actually
170. 5:22present was only about 22%. But this is
171. 5:25a step in the right direction because in
172. 5:27theory, it should enable more targeted
173. 5:29approaches for Alzheimer's treatment.
174. 5:31Because instead of just a shotgun
175. 5:33approach where treatments are given to
176. 5:34anyone who might have Alzheimer's, we
177. 5:36can now exclude those patients who
178. 5:38likely do not have Alzheimer's. But
179. 5:40coming back to if the result is
180. 5:41positive, it needs to be followed up
181. 5:43with further scans. And this is why the
182. 5:45test is only recommended for those who
183. 5:46are aged 55 and older and if clinical
184. 5:49symptoms of early dementia are present.
185. 5:51This is not a routine test where
186. 5:53otherwise healthy people would use it
187. 5:55because again a positive result is
188. 5:57likely to cause a lot of stress and
189. 5:58trigger further testing when it's
190. 6:00unlikely that there's actually a
191. 6:01problem. And this is why we should also
192. 6:03be really skeptical when companies
193. 6:04online they start advertising blood
194. 6:06tests that can help us detect
195. 6:08Alzheimer's early long before symptoms
196. 6:10appear. This is a classic case of why we
197. 6:12don't just run every test even if money
198. 6:14was no object. But let's back up a
199. 6:16second from testing for Alzheimer's
200. 6:18because the real question is how can we
201. 6:20prevent Alzheimer's? Because there are
202. 6:22many important risk factors that many
203. 6:23people don't consider. So in this next
204. 6:25video here, I detail how a simple
205. 6:27one-time intervention targeting this
206. 6:29risk factor might actually significantly
207. 6:31cut Alzheimer's risk. And this
208. 6:33intervention isn't a future possibility.
209. 6:35It's widely available