Reliance On Single Late-Stage Asset Will Expose Serious Long-Term Revenue And Earnings Risks

Catalysts

About Annexon

Annexon is a biotech company focused on C1q targeted therapies for serious neuroinflammatory and complement mediated autoimmune diseases affecting the body, brain and eye.

What are the underlying business or industry changes driving this perspective?

• Reliance on a single late stage asset in Guillain Barre syndrome, despite encouraging clinical signals and regulatory filings in the US and Europe, could expose Annexon to a scenario where any unexpected regulatory request for more data or label constraints limits the size and pace of GBS adoption. This would cap revenue and delay the move to sustained earnings.
• Expansion of the ARCHER II trial for geographic atrophy to include a second primary efficacy readout at month 24, while intended to strengthen the program, may prolong the development timeline and increase trial and overhead spending if the month 15 outcome is inconclusive. This would pressure net margins and extend the path to positive earnings.
• Growing use of complement targeted therapies across autoimmune and neurodegenerative conditions increases scientific interest in C1q inhibition. However, it also raises the risk that larger competitors develop alternative approaches that secure broader labels or earlier lines of therapy, which could limit Annexon’s pricing power and long term revenue opportunity in both GBS and geographic atrophy.
• Annexon’s use of a US$200 million credit facility and preparations for global commercialization increase fixed costs and financial leverage at a time when none of the key programs are approved. Any delay in regulatory decisions or slower than expected treatment uptake would leave interest expense and commercial infrastructure weighing on earnings and net margins.
• Positioning vonaprument as a potential vision preserving therapy in an aging population, where GA prevalence is projected to rise, depends on proving clinically meaningful visual benefits beyond current treatments. If longer term data do not clearly support superior real world outcomes, payers and clinicians may restrict use, limiting revenue scalability despite high upfront development and commercial investment.

Assumptions

How have these above catalysts been quantified?

• This narrative explores a more pessimistic perspective on Annexon compared to the consensus, based on a Fair Value that aligns with the bearish cohort of analysts.
• Annexon currently has no revenue. The bearish analysts are forecasting revenue to reach $155.5 million by August 2029.
• The bearish analysts are not forecasting that Annexon will become profitable in next 3 years. To represent the Analyst Price Target as a Future PE Valuation we will estimate Annexon's profit margin will increase from 0.0% to the average US Biotechs industry of 17.4% in 3 years.
• If Annexon's profit margin were to converge on the industry average, you could expect earnings to reach $27.1 million (and earnings per share of $0.14) by about August 2029, up from -$198.3 million today. However, there is a considerable amount of disagreement amongst the analysts with the most bullish expecting $410.1 million in earnings, and the most bearish expecting $-230.8 million.
• In order for the above numbers to justify the price target of the more bearish analyst cohort, the company would need to trade at a PE ratio of 27.5x on those 2029 earnings, up from -4.4x today. This future PE is greater than the current PE for the US Biotechs industry at 16.4x.
• The bearish analysts expect the number of shares outstanding to grow by 7.0% per year for the next 3 years.
• To value all of this in today's terms, we will use a discount rate of 7.44%, as per the Simply Wall St company report.

Risks

What could happen that would invalidate this narrative?

• Tanruprubart already has a marketing authorization application under review with the European Medicines Agency, and a Biologics License Application filing to the FDA is planned for the fourth quarter. Any eventual approvals or broad labels for Guillain Barre syndrome could support earlier revenue contribution and improve earnings compared with a scenario where Annexon remains pre commercial for an extended period.
• The geographic atrophy program for vonaprument is described as a potential hundred billion dollar plus franchise and targets an estimated 8 million patients worldwide. If the Phase III ARCHER II trial delivers statistically significant vision preservation at month 15 or month 24, this large and aging patient population could underpin meaningful long term revenue and support a path toward stronger net margins.
• Vonaprument holds FDA Fast Track and EMA PRIME designations and is in the EMA product development coordinator pilot. If this closer regulatory engagement leads to clearer guidance and smoother review cycles, the company could see less regulatory friction than expected, which would support more timely commercialization and reduce the risk of prolonged earnings pressure.
• The GA trial execution metrics, including more than 90% powering at both primary time points, over enrollment by 30 patients, less than 10% discontinuation and more than 95% dosing compliance, together with reproducible GBS data in western patients, indicate that Annexon is building a sizeable clinical evidence base that could support broader physician adoption and payer acceptance. This would help revenue scale and potentially support healthier net margins over time.

Valuation

How have all the factors above been brought together to estimate a fair value?

• The assumed bearish price target for Annexon is $3.0, which represents up to two standard deviations below the consensus price target of $13.25. This valuation is based on what can be assumed as the expectations of Annexon's future earnings growth, profit margins and other risk factors from analysts on the more bearish end of the spectrum.
• However, there is a degree of disagreement amongst analysts, with the most bullish reporting a price target of $27.0, and the most bearish reporting a price target of just $3.0.
• In order for you to agree with the more bearish analyst cohort, you'd need to believe that by 2029, revenues will be $155.5 million, earnings will come to $27.1 million, and it would be trading on a PE ratio of 27.5x, assuming you use a discount rate of 7.4%.
• Given the current share price of $5.34, the analyst price target of $3.0 is 78.0% lower. Despite analysts expecting the underlying business to improve, they seem to believe the market's expectations are too high.
• We always encourage you to reach your own conclusions though. So sense check these analyst numbers against your own assumptions and expectations based on your understanding of the business and what you believe is probable.