Chosa Oncology AbNGM: CHOSA

Annual report 2025 (CHOSA Oncology 2025 Year End Report UK)

Mar 23, 2026 at 8:28 AM UTC · Issued by Chosa Oncology AB

CHOSA Oncology AB (publ) |559037-2271 https://www.CHOSAoncology.com

Table of Contents

CEO Peter Buhl Letter Interim Report Q4 2025 3

CHOSA Oncology AB 4

Commentary on the group's financial development for the fourth quarter of year 7

Financial Reports - Group 9

Income statement in summary 9

Balance statement in summary 10

Change in equity 11

Cash flow analysis in summary 12

Financial Reports - Parent Company 13

Income statement in summary 13

Balance statement in summary 14

Change in equity 15

Cash flow analysis in summary 16

Company information 17

Upcoming financial reports 18

‌CEO Peter Buhl Letter Interim Report Q4 2025 CHOSA Oncology AB (publ)‌

The fourth quarter of 2025 marked a transformative period for CHOSA Oncology, characterized by significant scientific, strategic, and financial progress. Our mission - to increase precision and effectiveness in platinum-based chemotherapy through transcriptomic prediction - continues to gain strong international recognition, supported by robust clinical data and expanding global opportunities.

Expanding the Scientific and Commercial Foundation of Platin-DRP®

During the quarter, we announced a new patent application covering the use of our DRP® technology to predict synergy between platinum therapy and immunotherapy. This innovation targets one of the most important developments in modern oncology: combination regimens integrating platinum agents with immune checkpoint inhibitors. By extending our predictive platform into this rapidly growing therapeutic area, we are positioning CHOSA at the forefront of precision oncology in the immunotherapy era.

In parallel, we reported compelling new data demonstrating that Platin-DRP®, based on an alternative competitive method NanoString gene expression data, predicts overall survival in lung cancer patients treated with platinum-based therapy. Importantly, these findings effectively double the addressable market opportunity for Platin-DRP®, as we can now be positioned not only as a predictor of response, but also as a tool for survival benefit in non-small cell lung cancer (NSCLC). This represents a substantial expansion of our commercial potential and further strengthens the value proposition of our platform to both diagnostic and pharmaceutical partners.

Together, these developments reinforce CHOSA's position as a leader in transcriptomic precision tools for

platinum-based oncology treatment.

Strengthening Our Financial Platform - post the period

To support our continued development and commercialization efforts, CHOSA completed a directed issue of units raising approximately SEK 7.3 million before transaction costs. The capital strengthens our balance sheet and enables us to maintain momentum in regulatory preparation, partnership discussions, and further clinical and analytical validation work.

Yours sincerely, CEO Peter Buhl

CHOSA Oncology AB

CHOSA Oncology has developed Platin-DRP®, an easy-to-use predictive genetic test that helps physicians identify patients who will respond to treatment with cisplatin or carboplatin - two of the world's most widely used and effective cancer drugs. Platinum is the backbone of modern oncological treatment, often in combination with immunotherapy (PD-1/PD-L1 inhibitors) or other targeted drugs, and is used in 16 cancer indications, including lung and breast cancer - the two largest cancer indications.

Platin-DRP® is based on a 205-gene signature that analyzes tumor gene expression and generates a score predicting the patient's likelihood of treatment response. In September 2025, CHOSA, in collaboration with ETOP/EORTC, demonstrated that the technology can also predict the efficacy of carboplatin, opening up a much larger global market segment.

Focusing on neoadjuvant treatment for lung cancer, CHOSA aims to increase survival rates by making platinum treatment more precise, effective, and safer - thereby saving more lives.

The company's other asset, LiPlaCis®, is a liposomal platinum formulation that has shown promising results in previous clinical studies, with promising Phase 2b data and a favorable toxicity profile, and may eventually serve as a platform for new combination therapies.

Group Relationship and Shareholding

In accordance with Chapter 7, Section 23 of the Annual Accounts Act (ÅRL), CHOSA ApS is the acquirer of CHOSA Oncology AB (formerly RhoVac AB) because the shareholders of CHOSA ApS gained decisive influence in CHOSA Oncology AB. This means that CHOSA ApS is the accounting parent company, even though CHOSA Oncology AB is the legal acquirer of CHOSA ApS and thus the legal parent company of the group. The dormant company RhoVac ApS also belongs to the group.

In CHOSA Oncology's financial reports, CHOSA ApS is reported as the parent company and CHOSA Oncology AB as the parent company.

Operational Risks and Uncertainty Factors

The risks and uncertainty factors to which CHOSA's operations are exposed are, in summary, related to, among other things, drug development, competition, technology development, patents, regulatory

requirements, capital needs, currencies, and interest rates. For a more detailed account of risks and uncertainty factors, please refer to the Annual Report 2024, published on May 23, 2025, which is available on the Company's website.

The Share

The share in CHOSA Oncology AB (publ), formerly RhoVac AB (publ), was listed on Spotlight Stock Market ("Spotlight") on March 9, 2016. Spotlight operates a trading platform (MTF) and is a special corporate name for ATS Finans AB, a securities company under the supervision of the Swedish Financial Supervisory Authority. ATS Finans AB is a subsidiary of Spotlight Group AB, which as of September 15, 2020, is listed on Spotlight. As of December 31, 2025, the number of shares in Chosa amounted to 78,895,886 (64,873,913).

Shareholder List

For CHOSA's shareholder list, please refer to Spotlight via the following

link: https://spotlightstockmarket.com/sv/bolag/irabout?InstrumentId=XSAT01001554

Auditor's Review

The quarterly report has not been subject to review by the Company's auditor.

Submission of Quarterly Report 4 in English

CHOSA's commercialization strategy focuses on establishing partnerships with owners of PD(L)1 drugs or biosimilars to create combinations with Platin-DRP® as companion diagnostics. The company also intends to commercialize its tests through sales to pharmaceutical companies and/or hospitals for research use, either directly or via distribution partners.

Furthermore, CHOSA may enter into collaboration agreements or joint ventures, or in-license PD(L)-1 drugs, to develop PD(L)-1/Platin-DRP® combinations.

In addition to this, CHOSA is seeking partners or out-licensing for the drug candidate LiPlaCis®, which has shown good results in a Phase 2 study.

Activity plan in broad strokes

Continue dialogues with biotechnology and pharmaceutical companies and distributors for partnering
Utilize the clinical synergy between cisplatin and PD1/PD-L1 inhibitors when using our Platin DRP (such as Keytruda and Opdivo)
Attend ASCO, ESMO, and other relevant health and cancer conferences
Discuss clinical opportunities with Key Opinion Leaders (KOLs)
Validation of the DRP technology together with KOLs

‌Commentary on the group's financial development for the fourth quarter of year

Turnover and Earnings

The Group's other operating income for the fourth quarter amounted to 0 TSEK (38).

Chosa Aps has applied for tax credit during the year under the Danish 'Tax Credit Scheme' concerning development costs incurred during 2025. The effect of this tax credit is reported under the item tax on profit for the year.

Profit for the fourth quarter in the Group amounted to 699 TSEK (519).

Liquidity and Balance Sheet

The Group's liquid funds as of December 31, 2025, amounted to 1,791 TSEK (6,438).

In addition to the Group's liquid funds, the Group has prepaid costs and accrued income of 158 TSEK (72), as well as tax receivables of 1,162 TSEK (861). In the event that research and development expenses are incurred in the Danish subsidiary, a tax credit may be obtained, according to the "Tax Credit Scheme" in Denmark. According to this, Chosa ApS can obtain a current tax income for a portion of the expenses attributable to research and development costs. During Q1 2026, an application was made related to the work activated as an intangible asset in the Danish subsidiary. The tax receivable for this amounts to 694 TDKK. Trade payables amounted to 2,714 TSEK (1,670). Equity amounts to 16,543 TSEK (18,630) of a total balance sheet of 20,252 TSEK (21,402).

During February 2026, Chosa Oncology AB carried out a directed issue of 7.3 MSEK before transaction costs. 8,967,786 shares have been registered with the Swedish Companies Registration Office, meaning the number of shares in the Company has increased from 78,895,886 shares to 87,863,672 shares. The increase in the number of shares also means that the share capital in the Company has increased by 1,614,201.48 SEK, from 14,201,259.48 SEK to 15,815,460.96 SEK.

In addition to the shares, 8,967,786 warrants of series TO3 ("TO3") have been issued. One (1) TO3 gives the holder the right to subscribe for one (1) new share. The exercise price for TO3 amounts to 1.025 SEK per new share, which corresponds to 125 percent of the subscription price per share in the Directed Issue. TO3 can be used for subscription of new shares in CHOSA during the period 3-17 November 2026. TO3 will not be traded on Spotlight Stock Market.

Solvency

The Group's solvency as of December 31, 2025, amounted to 82% (83).

Correction of Errors

Comparative figures for 2024 have been corrected by recalculation in accordance with generally accepted accounting principles.

The error concerns capitalized work for own account and associated tax credit that were incorrectly reported in Q2 2025 but should rightfully relate to 2024.

The effect on 2024 amounts to the following sums, recalculated to SEK according to the exchange rate per 2024-12-31:

• +2.6 MDKK in capitalized work for own account

• +459 TDKK in tax credit

The correction affects equity as of December 31, 2024, by the corresponding net amount. Year-End Report Jan-Dec 2025 | CHOSA Oncology AB (publ)

‌Financial Reports - Group ‌Income statement in summary

The Group	01-10-2025	01-10-2024	01-01-2025	01-01-2024
	31-12-2025	31-12-2024	31-12-2025	31-12-2024
	(TSEK)	(TSEK)	(TSEK)	(TSEK)
Operating Revenues
Capitalized work performed for own use	4.607	4.114*	4.607	4.114*
Other operating income	0	38	3	44
Operating Expenses
Cost of External services	-3.387	-3.227	-7.748	-8.326
Staff Costs	-689	-473	-2.358	-713
Depreciation and amortization of intangible assets	-647	-684	-730	-684
Other operating expenses	-4	-34	-5	-35
Operating Profit	-120	-266	-6.233	-5.599
Finance Income and Expenses
Interest income and similar income	209	54	328	394
Interest expense and similar charges	-404	23	-720	-273
Net Financial Result	-315	-189	-6.624	-5.479
Income Tax Expense	1.014	707*	1.014	707*
NET INCOME FOR THE YEAR/PERIOD	699	519	-5.611	-4.772

* See comment in section Correction of errors in comment on the group's financial development

‌Balance statement in summary

The Group	31/12/2025 31/12/2024 (TSEK) (TSEK)		The Group		31/12/2025 31/12/2024 (TSEK) (TSEK)
Assets				EQUITY AND LIABILITIES
Fixed assets				Equity
Intangible fixed assets				Share capital (78,895,886 shares)	14.201	12.770
Capitalized expenses for development work	8.434	4.107*
Patent	8.184	9.556		Other restricted equity	7.550	3.985*
Total fixed assets	16.618	13.663		Other contributed capital	10.624	10.527
				Other equity including this year's result	-15.832	8.651*
Current assets				Equity attributable to the parent company's shareholders	16.543	18.630
Short-term receivables
Current tax assets	1.162	861*		Total equity	16.543	18.630
Other receivables	524	368
Prepaid expenses and accrued income	158	72		Current liabilities
Total current receivables	1.844	1.301		Accounts payable	2.714	1.670
				Other current liabilities	252	355
Cash and bank	1.791	6.438		Accrued expenses and prepaid income	742	747
				Total current liabilities	3.708	2.772
Total current assets	3.634	7.739
				TOTAL EQUITY AND LIABILITIES	20.252	21.402
TOTAL ASSETS	20.252	21.402

* See comment in section Correction of errors in comment on the group's financial development

‌Change in equity
The Group	Share capital	Other contributed capital	Other equity, incl. this year's result	Total equity attributable to parent company shareholders	Total equity
	(TSEK)	(TSEK)	(TSEK)	(TSEK)	(TSEK)

Opening balance at 1 January, 2025	12.770	10.527	-4.667	18.630	18.630
Appropriation of previous year's profit					0
Profit for the year			-5.611	-5.611	-5.611
Transfer from share premium reserve		-2.755	2.755
Changes in carrying amounts
Foreign currency translation differences			-760	-760	-760

Total changes in equity	0	-2.755	-3.616	-6.371	-6.371
Transactions with owners:
Share issue	1.431	2.852	0	4.283	4.283
Total transactions with shareholders	1.431	2.852	0	4.283	4.283
CLOSING BALANCE AT 31 DECEMBER, 2025	14.201	10.624	-8.282	-16.543	-16.543
The Group	Share capital	Other contributed capital	Other equity, incl. this year's result	Total equity attributable to parent company shareholders	Total equity
	(TSEK)	(TSEK)	(TSEK)	(TSEK)	(TSEK)

Opening balance at 1 January, 2024	11.677	6.086	-352	17.411	17.411
Profit for the year			-4.772	-4.772	-4.772
Foreign currency translation differences			457	457	457
Total changes in equity	0	0	-4.315	-4.315	-4.315
Transactions with owners:
Share issue	1.093	4.441		5.534	5.534

Total transactions with shareholders	1.093	4.441	0	5.534	5.534
CLOSING BALANCE AT 31 DECEMBER, 2024	12.770	10.527	-4.667	16.630	16.630

* See comment in section Correction of errors in comment on the group's financial development

‌Cash flow analysis in summary

The Group	01/10/2025	01/10/2024	01/01/2025	01/01/2024
	31/12/2025	31/12/2024	31/12/2025	31/12/2024
	(TSEK)	(TSEK)	(TSEK)	(TSEK)
The ongoing operations
Operating profit	-120	-266*	-6.233	-5.599*
Adjustments for items that are not included in cash flow:	1.753	1.435	1.908	1.516
Received interest	209	54	328	394
Paid interest	-357	-69	-421	-519
Withheld/paid income tax	-171	-580	-301	-706
Cash flow from operating activities before changes in working capital	1.314	574	-4.718	-4.915
Cash flow from changes in working capital
Decrease (+)/increase (-) of other current receivables	-270	-285	-242	159
Decrease(-)/increase(+) in accounts payable	2.571	374	1.044	836
Decrease(-)/increase(+) of other current liabilities	174	-149	-108	-79
Cash flow from operating activities	3.788	514	-4.024	-3.999
Investment activities
Investment in intangible fixed assets	-4.607	-4107*	-4.607	-4114*
Cash flow from investing activities	-4.607	-4.107	-4.607	-4.114
Financing activities
New share issue	0	0	4.930	5.585
Emission costs	0	0	-647	-51
Cash flow from financing activities	0	0	4.283	5.534
This year's cash flow	-818	-3593	-4348	-2580
Cash and cash equivalents at the beginning of the year/period	2657	9939	6438	8772
Exchange rate differences in cash and cash equivalents	-47	91	-299	245
CASH AND CASH EQUIVALENTS AT THE END OF THE YEAR/PERIOD	1.791	6.438	1.791	6.438

‌Financial Reports - Parent Company

‌Income statement in summary

Parent Company - CHOSA Oncology AB	01/10/2025	01/10/2024	01/01/2025	01/01/2024
	31/12/2025 (TSEK)	31/12/2024 (TSEK)	31/12/2025 (TSEK)	31/12/2024 (TSEK)
Operating Revenues Net sales	1.583	34	1.768	0
Other operating income	0	0	3	40
Operating Expenses Cost of External services	-919	-714	-2.617	-2.926
Staff Costs	-115	-110	-447	-350
Other operating expenses	-4	-34	-5	-35
Operating Profit	544	-824	-1.299	-3.271
Finance Income and Expenses Interest income and similar income	117	148	503	583
Interest expense and similar charges	0	-61	-138	-313
Profit after financial items	661	-737	-934	-3.001
Profit before tax	661	-737	-934	-3.001
Tax on this year's profit	0	0	0	0
NET INCOME FOR THE YEAR/PERIOD	661	-737	-934	-3.001

‌Balance statement in summary

Parent Company -

CHOSA Oncology AB 31/12/2025 31/12/2024

Parent Company -

CHOSA Oncology AB 31/12/2025 31/12/2024

(TSEK) EUR (TSEK) EUR (TSEK) EUR (TSEK) EUR EQUITY AND LIABILITIES

Fixed assets Equity

Financial fixed assets Restricted equity

Shares in group

companies

45.914

Equity capital 14.201

12.770

Receivables from group companies

7.134

Total restricted equity 14.201

12.770

Total financial fixed assets

53.048

Free equity

Total fixed assets 53.048 53.048 Share premium reserve 257.627 254.774

Balanced profit or loss -212.466 -212.465 Profit for the

Current assets year/period -934 -3.001

Short-term receivables			Total unrestricted equity 41.227	39.308
Receivables from group companies	2.552	580
Tax receivables	156	155	Total equity 55.428	52.078
Other receivables	79	137
Prepaid expenses and accrued income	158	72	Short-term liabilities
Total current receivables	2.915	944	Liabilities to group companies 0	2.948
			Accounts payable 177	91
Cash and bank	365	2.176	Other current liabilities 0	24
			Accrued expenses and prepaid income 724	1.025
Total current assets	2.199	3.120	Total current liabilities 901	4.088

TOTAL EQUITY AND

LIABILITIES 56.328

56.167

TOTAL ASSETS 56.328 56.167

‌Change in equity
Parent Company - CHOSA Oncology AB	Share capital	Other contributed capital	Balanced profit or loss	This year's result	Total equity
	(TSEK)	(TSEK)	(TSEK)	(TSEK)	(TSEK)

Opening balance at January 1, 2025	12.770	254.774	-212.465	-3.001	52.078
Appropriation of previous year's profit			-3.001	3.001	0
This year's result				-934	-934
Transactions with owners:
New share issue	1.431	2.852		0	4.283
Total transactions with shareholders	1.431	2.852	0	0	4.283
CLOSING BALANCE AT 31 Dec 2025	14.201	257.626	-215.465	-934	55.428
Parent Company - CHOSA Oncology AB	Share capital	Other contributed capital	Balanced profit or loss	This year's result	Total equity
	(TSEK)	(TSEK)	(TSEK)	(TSEK)	(TSEK)

Opening balance at January 1, 2024	11.677	250.333	-206.887	-5.578	49.545
Appropriation of previous year's profit			-5.578	5.578	0
This year's result				-3.001	-3.001
Transactions with owners:
New share issue	1.093	4.441		0	5.534
Total transactions with shareholders	1.093	4.441	0	0	5.534
CLOSING BALANCE AT 31 Dec 2024	12.770	254.774	212.465	3.001	52.078

‌Cash flow analysis in summary

Parent Company - CHOSA Oncology AB	01/10/2025	01/10/2024	01/01/2025	01/01/2024
	31/12/2025	31/12/2024	31/12/2025	31/12/2024
	(TSEK)	(TSEK)	(TSEK)	(TSEK)
The ongoing operations
Operating profit	545	-824	-1.299	-3.272
Received interest	2	3	503	4
Paid interest	0	0	-138	-142
Paid income tax	125	-155	-2	1
Cash flow from operating activities before changes in working capital	671	-976	-936	-3.409
Cash flow from changes in working capital
Decrease (+)/increase (-) of other current receivables	-1.772	-54	-1.970	59
Decrease(-)/increase(+) in accounts payable	62	23	85	-154
Decrease(-)/increase(+) of other current liabilities	276	1.040	-3.274	-1.333
Cash flow from operating activities	-163	-2.047	-6.094	-4.955
Financing activities
New share issue	0	0	4.930	5.585
Emission costs	0	0	-647	-51
Cash flow from financing activities	0	0	4.283	5.534
This year's cash flow	-163	-2.047	-1.811	579
Cash and cash equivalents at the beginning of the year/period	528	4.223	2.176	1.597
CASH AND CASH EQUIVALENTS AT THE END OF THE YEAR/PERIOD	365	2.176	365	2.176

‌Company information

CHOSA Oncology AB - parent company

RhoVac ApS - subsidiary

Country of Incorporation

Denmark

Company name CHOSA Oncology AB

Trade name

"CHOSA".Shares are subject to trading on

Spotlight.

Country where

subsidiary operate Denmark

ISIN code SE0007784319

Company Registration

Number 31159008

Registered Office Lund Municipality, Skåne County, Sweden Ownership share 100%

Company Registration

Number 559037-2271

Date of Incorporation 28/10/2015

Commencement of Operations

25/11/2015

CHOSA Oncology ApS - subsidiary

Country of Incorporation Sweden

Country of Incorporation

Denmark

Legal form Public limited company

Governing Law

Swedish law and the Swedish Companies

Act

Country where

subsidiary operate Denmark

Address

c/o ECIT Services AB, Kungsgatan 6, SE-211 49 Malmö

Company Registration

Number 43134477

Phone number +45 2160 8922 Ownership share 100%

Website https://www.chosaoncology.com

Auditor

Deloitte AB (Box 386, Se-201 23 Malmö), Chief Auditor Maria Ekelund

Legal Entity Identifier 5493002SFL9YXB0A0027

‌Upcoming financial reports

CHOSA prepares and publishes a financial report at each quarter-end. Upcoming reports are planned as follows:

Activity plan in broad terms

Annual report 2025 May 20, 2026
Annual General Meeting 2026 May 27, 2026
Interim report Q1 2026 May 30, 2026

This UK version of the Q4 2025 report is an unaudited translation from the audited Swedish report

CHOSA Oncology AB

Visitor Address (Denmark): Ole Maaløes vej 3, DK-2200 Copenhagen N, Denmark

Visitor Address (Sweden): c/o ECIT Services AB Kungsgatan 6, SE-211 49 Malmö, Sweden Postadress: c/o ECIT Services AB Kungsgatan 6, SE-211 49 Malmö, Sweden

Org.nr: 559037-2271