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Side-by-side financial comparison of Amylyx Pharmaceuticals, Inc. (AMLX) and PROTHENA CORP PUBLIC LTD CO (PRTA). Click either name above to swap in a different company.

Over the past eight quarters, PROTHENA CORP PUBLIC LTD CO's revenue compounded faster (-35.2% CAGR vs -100.0%).

Amylyx Pharmaceuticals, Inc is a biopharmaceutical company headquartered in Cambridge, Massachusetts. Amylyx is best known for AMX0035, an experimental therapy for amyotrophic lateral sclerosis. AMX0035 was approved for medical use in Canada as Albrioza, in June 2022, and in the United States, as Relyvrio, in September 2022. It was withdrawn in April, 2024.

Prothena Corporation plc is a late-stage clinical biotechnology firm focused on developing and commercializing innovative antibody therapies for neurodegenerative disorders, rare diseases and immune-related conditions. Its core pipeline targets unmet medical needs including amyloidosis, Parkinson's and Alzheimer's, serving key markets across North America, Europe and the Asia-Pacific.

AMLX vs PRTA — Head-to-Head

Bigger by revenue
PRTA
PRTA
Infinity× larger
PRTA
$21.0K
$0
AMLX
Faster 2-yr revenue CAGR
PRTA
PRTA
Annualised
PRTA
-35.2%
-100.0%
AMLX

Income Statement — Q4 FY2025 vs Q4 FY2025

Metric
AMLX
AMLX
PRTA
PRTA
Revenue
$0
$21.0K
Net Profit
$-33.0M
Gross Margin
Operating Margin
Net Margin
Revenue YoY
-99.0%
Net Profit YoY
12.1%
62.7%
EPS (diluted)
$-0.28

Green = leading value per metric. Periods may differ when fiscal calendars don't align.

8-Quarter Revenue & Profit Trend

Side-by-side quarterly history. Quarters aligned by calendar period so offset fiscal years line up.

Revenue
AMLX
AMLX
PRTA
PRTA
Q4 25
$0
$21.0K
Q3 25
$0
$2.4M
Q2 25
$0
$4.4M
Q1 25
$0
$2.8M
Q4 24
$-665.0K
$2.1M
Q3 24
$416.0K
$970.0K
Q2 24
$-1.0M
$132.0M
Q1 24
$88.6M
$50.0K
Net Profit
AMLX
AMLX
PRTA
PRTA
Q4 25
$-33.0M
Q3 25
$-34.4M
$-36.5M
Q2 25
$-41.4M
$-125.8M
Q1 25
$-35.9M
$-60.2M
Q4 24
$-37.5M
Q3 24
$-72.7M
$-59.0M
Q2 24
$-72.7M
$66.9M
Q1 24
$-118.8M
$-72.2M
Gross Margin
AMLX
AMLX
PRTA
PRTA
Q4 25
Q3 25
Q2 25
Q1 25
Q4 24
Q3 24
Q2 24
100.8%
Q1 24
93.3%
Operating Margin
AMLX
AMLX
PRTA
PRTA
Q4 25
Q3 25
-1666.3%
Q2 25
-1914.4%
Q1 25
-2319.0%
Q4 24
6113.4%
Q3 24
-18187.7%
-6857.0%
Q2 24
7457.1%
44.2%
Q1 24
-137.8%
-163056.0%
Net Margin
AMLX
AMLX
PRTA
PRTA
Q4 25
Q3 25
-1513.1%
Q2 25
-2845.4%
Q1 25
-2128.5%
Q4 24
5646.0%
Q3 24
-17476.9%
-6082.6%
Q2 24
7106.5%
50.7%
Q1 24
-134.0%
-144478.0%
EPS (diluted)
AMLX
AMLX
PRTA
PRTA
Q4 25
$-0.28
Q3 25
$-0.37
$-0.68
Q2 25
$-0.46
$-2.34
Q1 25
$-0.42
$-1.12
Q4 24
$-0.54
Q3 24
$-1.07
$-1.10
Q2 24
$-1.07
$1.22
Q1 24
$-1.75
$-1.34

Balance Sheet & Financial Strength

Snapshot of each company's liquidity, leverage and book value from the latest quarter.

Metric
AMLX
AMLX
PRTA
PRTA
Cash + ST InvestmentsLiquidity on hand
$317.0M
$307.5M
Total DebtLower is stronger
Stockholders' EquityBook value
$305.3M
$280.5M
Total Assets
$332.6M
$326.8M
Debt / EquityLower = less leverage

8-quarter trend — quarters aligned by calendar period.

Cash + ST Investments
AMLX
AMLX
PRTA
PRTA
Q4 25
$317.0M
$307.5M
Q3 25
$344.0M
$330.8M
Q2 25
$180.8M
$371.4M
Q1 25
$204.1M
$417.9M
Q4 24
$176.5M
$471.4M
Q3 24
$234.4M
$519.3M
Q2 24
$309.8M
$564.1M
Q1 24
$373.3M
$546.5M
Stockholders' Equity
AMLX
AMLX
PRTA
PRTA
Q4 25
$305.3M
$280.5M
Q3 25
$332.0M
$295.0M
Q2 25
$167.9M
$324.3M
Q1 25
$201.4M
$437.7M
Q4 24
$164.8M
$486.9M
Q3 24
$196.2M
$534.4M
Q2 24
$261.3M
$581.9M
Q1 24
$324.4M
$502.4M
Total Assets
AMLX
AMLX
PRTA
PRTA
Q4 25
$332.6M
$326.8M
Q3 25
$362.7M
$352.6M
Q2 25
$194.6M
$399.1M
Q1 25
$219.7M
$495.3M
Q4 24
$193.6M
$547.1M
Q3 24
$250.7M
$595.3M
Q2 24
$332.2M
$645.6M
Q1 24
$417.5M
$623.2M

Cash Flow & Capital Efficiency

How much cash each business actually produces after reinvestment. Cash flow is harder to manipulate than net income.

Metric
AMLX
AMLX
PRTA
PRTA
Operating Cash FlowLast quarter
$-27.9M
$-163.6M
Free Cash FlowOCF − Capex
$-28.0M
FCF MarginFCF / Revenue
Capex IntensityCapex / Revenue
Cash ConversionOCF / Net Profit
TTM Free Cash FlowTrailing 4 quarters
$-123.5M

8-quarter trend — quarters aligned by calendar period.

Operating Cash Flow
AMLX
AMLX
PRTA
PRTA
Q4 25
$-27.9M
$-163.6M
Q3 25
$-30.4M
$-40.6M
Q2 25
$-25.2M
$-46.3M
Q1 25
$-39.8M
$-53.4M
Q4 24
$-59.0M
$-150.1M
Q3 24
$-41.6M
$-45.2M
Q2 24
$-66.6M
$16.0M
Q1 24
$-489.0K
$-73.1M
Free Cash Flow
AMLX
AMLX
PRTA
PRTA
Q4 25
$-28.0M
Q3 25
$-30.4M
Q2 25
$-25.3M
Q1 25
$-39.8M
Q4 24
$-59.0M
Q3 24
$-41.6M
Q2 24
$-66.7M
Q1 24
$-556.0K
FCF Margin
AMLX
AMLX
PRTA
PRTA
Q4 25
Q3 25
Q2 25
Q1 25
Q4 24
8876.4%
Q3 24
-9997.4%
Q2 24
6517.0%
Q1 24
-0.6%
Capex Intensity
AMLX
AMLX
PRTA
PRTA
Q4 25
Q3 25
Q2 25
Q1 25
Q4 24
-3.0%
Q3 24
4.6%
Q2 24
-8.7%
Q1 24
0.1%
Cash Conversion
AMLX
AMLX
PRTA
PRTA
Q4 25
Q3 25
Q2 25
Q1 25
Q4 24
Q3 24
Q2 24
0.24×
Q1 24

Financial Flow Comparison

Revenue → gross profit → operating profit → net profit for each company.

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