Autism drug L1-79 and partial proxies available today, from ultra expensive to affordable - in search of a happier homeostasis

 

 

Click to enlarge (very detailed)

I was recently asked about the promising autism research drug L1-79 and the idea of using a similar drug called Demser as an immediately accessible alternative.

It is an interesting question, but I do wonder if that reader had checked out how much Demser costs. Even I was shocked, $100,000 to $500,000 per year in the US.

Demser is an old generic drug but with a tiny market, so it never became cheap. It was developed to treat a rare tumor of the adrenal glands that leads to the production of  excess catecholamines.

You can make the case that L1-79 is just a low-dose (about 1/10^th) re-packaged version of Demser, to be sufficiently different to be patentable as a new drug.

L1-79 has shown promise in a very small trial to improve social responsiveness in adolescents with autism, but no intellectual disability. This is great news, but realistically how much is that worth?

Clever drugs are great, but they have to be affordable.

 

L1-79 Clinical Trial

https://live-yamopharma.pantheonsite.io/wp-content/uploads/2024/11/CNS-Conference-Poster.pdf

The clinical trial suggests that reducing catecholamine “noise” (dopamine + noradrenaline) can improve social engagement in some people with autism.

 A Phase 2 randomized, double-blind, placebo-controlled crossover study tested L1-79 in adolescents and young adults with autism (IQ ≥ 70).

Key results:

• Significant improvement in socialization
• Vineland-3 Socialization score increased 8 points (clinically meaningful)
• Improvements also seen in:
• Play & leisure
• Clinician (CGI-S) and caregiver ratings
• Well tolerated
• No serious adverse events
• No withdrawals due to side effects

 The most interesting finding

The crossover phase failed due to:

• Carryover effect → benefits persisted after stopping
• Sequence effect → order of treatment influenced results

Only the first 12-week period was usable

The drug may create a temporary window for improved engagement, with some effects persisting after discontinuation. This is actually a good thing.

 

What L1-79 actually is

L1-79 is described as a racemic formulation of alpha-methyl-para-tyrosine (AMPT)

This is the same core compound used in Demser.

Alpha-methyl-para-tyrosine (AMPT) is a molecule with two mirror-image forms:

•          R-enantiomer

•          S-enantiomer

Consider it like a pair of gloves, one is right-handed and the other is left-handed.

 

Both L1-79  and Demser are essentially:

• 50% R-AMPT + 50% S-AMPT
• Same mechanism:
• inhibition of tyrosine hydroxylase
• ↓ dopamine
• ↓ noradrenaline

 

So are L1-79 and Demser identical?

Chemically, yes (or extremely close).

The pharmokinetics may have been improved to give a more stable effect.

 

The target phenotype for L1-79

Best described as:

“Too dysregulated to engage socially effectively”

Features:

• Over-aroused / “wired”
• Inconsistent engagement
• Easily overwhelmed
• Better in calm environments

Not lack of social interest — but loss of access

This autism treatment aims to reduce background neurochemical noise to improve signal-to-noise ratio.

 

Why not just use Demser?

This was the exact question posed to me. It is a great question, until you see the crazy price of Demser.

 

Are there any affordable alternatives today?

No direct equivalent

There is no cheap drug that safely and precisely reduces catecholamine synthesis for CNS use.

 

Partial proxies (available today)

1. Guanfacine

• ↓ noradrenergic tone
• improves regulation

 2. Clonidine

• stronger, more sedating

 3. Propranolol

• reduces adrenergic stress response

 

Does reducing catecholamine-driven dysregulation improve social engagement?

 Positive signs:

• more sustained interaction
• better back-and-forth
• increased shared attention

 

Negative signs:

• flat affect
• reduced motivation

 

Clonidine and guanfacine:

• have been trialed in autism
• improve:
• hyperactivity
• irritability

but do not consistently improve socialization.

 

Propranol

Propranolol helps when stress blocks performance.

It is good for social anxiety.

Propranolol can improve certain aspects of social and cognitive performance — especially under stress — but does not broadly change core autism symptoms.

Feature	Propranolol	Guanfacine	Clonidine	L1-79	Demser (metyrosine)
Mechanism level	Downstream	Downstream	Downstream	Upstream	Upstream
Main effect	↓ stress response	↓ noradrenergic noise (PFC)	↓ global noradrenergic tone	↓ dopamine + noradrenaline (controlled)	↓ dopamine + noradrenaline (strong)
Dopamine effect	Minimal	Minimal	Minimal	Reduced	Reduced (more strongly)
Noradrenaline effect	↓ peripheral + some CNS	↓ targeted	↓ broader	↓ global, moderate	↓ global, strong
Best for	Anxiety / performance stress	Regulation, attention	Hyperarousal, sleep	“Noisy” dysregulated system	Extreme catecholamine excess
Effect on socialization	Situational	Indirect	Indirect	Direct (trial signal)	Not studied
Consistency	Context-dependent	Moderate	Moderate	More sustained	Variable
Sedation risk	Low–moderate	Low	Moderate–high	Low–moderate	High if overdosed
Precision	Medium	Good	Lower	High (goal)
ASD use	Sometimes	Common	Common	Experimental	Not used

Slide left-right

A broader perspective: not one direction, but a spectrum

One important takeaway from L1-79 is that it highlights a direction of treatment, not a universal solution. Catecholamine function (dopamine and noradrenaline) operates along a spectrum. Some individuals have excess or unstable signaling (too much noise), others have insufficient drive (too little signal), and many show poor regulation between the two states.

This pattern is seen across multiple conditions:

Attention Deficit Hyperactivity Disorder

·        often low dopamine / noradrenaline tone

·        stimulants increase them

Depression

·        can involve low catecholamine activity, classic antidepressants will not work

·        need the opposite of L1-79 which could be Bupropion (1,000 times cheaper than Demser)

Anxiety disorders

·        often high noradrenergic tone

Autism Spectrum Disorder

·        likely heterogeneous

o   some hyper (too much)

o   some hypo (too little)

o   many dysregulated

The key insight is that the goal is not simply “increase” or “decrease,” but restore optimal regulation — the point at which signal is strong enough to support engagement, but not so strong that it creates noise and instability.

This has important implications. If catecholamine dysregulation is common and cuts across multiple conditions, then treatments targeting this system are likely to have broad relevance, not niche application. In that context, affordability becomes critical. A highly priced, specialist drug risks restricting access to a mechanism that may benefit a large population.

The challenge is not discovering the mechanism — it is making it usable, scalable, and affordable in everyday clinical practice.

As with many aspects of autism, or indeed depression, anxiety, ADHD etc, all you are doing is fine-tuning an imbalanced system. Consider it like finding a happier homeostasis.

Conclusion

The effective dosage of L1-79 was not found to be weight based. People in the trial were aged 12 to 21 years old. The effective dose was 300-600mg split into 2 doses day.

L1-79 reduces synthesis of:

• dopamine
• norepinephrine
• These are not just "bad when high" they are essential for function 

Think of it as a narrow window

• Too high (overactive system):
• agitation
• irritability
• poor regulation

• Optimal zone:
• calmer
• more focused
• better engagement

• Too low (over-suppressed):
• low motivation
• emotional flattening
• fatigue / low energy

L1-79 pushes you downward on this curve, so overshooting is very possible

Even though trials used up to 600 mg/day. Some people likely responded best at lower doses (300–400 mg/day). Others may have improved initially but then lost drive or engagement at higher doses.

The standard dosage of Demser/Metyrosine for pheochromocytoma is 1,500–4,000 mg/day.

If someone was in the phase 2 trial and responded really well to L1-79 at 250mg twice a day, you could understand their interest to just switch to 250mg twice a day of Demser. 

That would cost €60–€150 per day in Europe and very much more in the US.

I did ask AI to guess the price of L1-179, if it gets approved.

 

Likely pricing strategy for L1-79

Even though it uses lower doses, expect:

·         US price:
👉 ~$30,000–$80,000 per year
(very typical for autism CNS drugs)

·         Europe:
👉 €10,000–€30,000 per year (after negotiation)

 

The original Demser drug was approved by the FDA in 1979.

Demser is cheap to produce, so if L1-79 gets approved in the US for autism maybe the Chinese will trial low-dose Demser. If successful, that would create a large market and the price should fall. There is no patent to worry about.

Drug producers do see a market in the US for autism drugs costing $50,000 a year. Unfortunately, many people with disabling autism will require multiple drugs, targeting different aspects of their condition. It is not a case of pay $50,000 and you are "done."

The idea is that if insurance in the US is currently paying $100,000 to $200,000 a year for therapy for a child with level 3 autism, they can afford $50,000 for our pills.

In Europe the spending on therapies outside of school is dramatically less, more like up to €10,000 a year. European countries frequently reject new drugs because they are too expensive, or they just severely restrict access to keep costs down. 

The good news is that there is no shortage today of affordable pharmaceutical interventions that can improve troubling aspects of many sub-types of autism. You likely will need to stack them together in a personalized polytherapy. Don't expect any single drug to be a silver bullet, no matter how expensive it might be.