EIC Accelerator Check: RhoVac and Its Prostate Cancer Vaccine

RhoVac set out to do something no approved cancer drug does: train the immune system to find and kill the first cells that break away from a tumour, before they settle elsewhere as metastases. Its candidate, RV001 (later named onilcamotide), was selected in the European Commission's 5 June 2019 EIC SME Instrument Phase 2 list, where RHOVAC of Hørsholm, Denmark, is the only company named for the project. CORDIS shows an EU contribution of €2,499,900 towards a total cost of €5,273,880, for a project that ran from 1 October 2019 to 30 September 2022, according to the CORDIS fact sheet. The money paid for a Phase IIb trial in 180 men. The trial was completed and failed its primary endpoint in May 2022, according to pharmaphorum and BioSpace.

The vaccine is no longer being developed. In January 2023 the Swedish listed parent, RhoVac AB, completed a reverse takeover of the Danish oncology company Chosa ApS and took on its management, according to the company's announcement, and it was renamed CHOSA Oncology AB, according to a Cision release. The group has pivoted to a biomarker that predicts response to platinum chemotherapy. The Danish grant holder, RHOVAC ApS, still exists but reported no development or commercial activity in 2025.

Where RhoVac Stands Now

RHOVAC ApS, the Danish company that held the grant, has become a dormant subsidiary inside the CHOSA group. Its 2025 annual report, filed with the Danish Business Authority and approved on 19 May 2026, states that the company "has been without development and commercial activity" during the year. It shows a loss of DKK 586,902, cash of DKK 31,544 and negative equity of DKK 693,847, and the management notes that more than half of the share capital has been lost. North Data lists the company as active, with Peter Buhl and Claus F. Pedersen appointed as directors in 2023 and the former RhoVac chief executive Lars Hedbys removed.

The same report records an obligation to the Danish Cancer Society (Kræftens Bekæmpelse): RHOVAC ApS must pay GBP 100,000 plus royalties if products covered by a patent application of 18 December 2008 are approved in the EU or the US. No such approval is in prospect. The company's former website, rhovac.com, now shows a web host's placeholder page.

The listed parent is active under its new name. CHOSA Oncology published its first-quarter 2026 report on 27 May 2026, with a loss after financial items of SEK 1,867 thousand and no revenue, and it presented data on its Platin-DRP biomarker at ASCO 2026. Neither document mentions RV001.

The Technology: A Peptide Vaccine Against RhoC

RhoC is a protein that cancer cells with the ability to spread produce in high amounts. RV001 combined fragments of RhoC with the adjuvant Montanide ISA 51 and was injected under the skin, so that the patient's T cells would learn to recognise and destroy cells carrying the protein, according to an Edison Investment Research report from May 2019. The target group was men whose PSA, the prostate cancer blood marker, rises again after surgery or radiotherapy that was meant to cure them. Up to 40% of prostate cancer patients relapse in the first two years after surgery, the CORDIS summary says.

The difference from established care was timing. These patients are usually monitored until the cancer returns visibly and then receive hormone therapy. Approved alternatives at the time, such as the cell-based immunotherapy Provenge and the hormone drugs Zytiga and Xtandi, act on cancer that has already advanced, Edison noted. RhoVac wanted a cheap, well-tolerated injection given early, which would keep micro-metastases from growing at all.

The early data looked good. In a Phase I/II trial completed in 2018, 22 patients received 11 injections over 30 weeks; 18 of 21 evaluable patients (86%) mounted a significant immune response, and the response was still strong 12 months after the last dose, according to the CORDIS project report and Edison. An immune response, however, is not the same as clinical benefit, and that gap is what the EU-funded trial was meant to close.

What the EIC Project Promised, and What It Delivered

The CORDIS objective named one key goal: take RV001 "up to completion of a Phase IIb clinical trial", then out-license the vaccine to a large pharmaceutical company, with "conservatively predicted revenues of ca. €1B" within five years of launch. RhoVac also said it would test the vaccine in other cancers "exploratively in parallel".

The trial itself was delivered. BRaVac (NCT04114825), a randomised, double-blind, placebo-controlled study, enrolled its first patient on 19 November 2019 at sites in the United States, Belgium, Denmark, Finland, Germany, Sweden and the United Kingdom, according to ClinicalTrials.gov. In November 2020 the US FDA granted RV001 Fast Track designation, according to Edison and Nordic Life Science. Recruitment closed in September 2021 with 180 patients, according to Nordic Life Science and BioStock.

The timing slipped but stayed within the grant. In December 2019 RhoVac expected the study to finish in September 2021, according to BioStock; the company later cited delays from the Covid-19 pandemic. The topline result came on 30 May 2022, four months before the EU project ended: RV001 did not prevent progression, defined as a doubling of PSA, clinical recurrence or death, better than placebo. The share price fell 94% in morning trading, pharmaphorum reported.

The rest of the plan collapsed with the readout. On 30 June 2022 RhoVac said further analysis had found "nothing of substance" that would justify more studies, stopped the long-term follow-up, ended its contract with the research organisation running the trial and gave notice to its development head, according to the company's status update and BioStock. No licence deal followed, and no study of RV001 in another cancer was announced. A CORDIS results story confirms that the expected immune response occurred but the clinical endpoints were not reached, and that no severe adverse effects were reported.

1. Complete a Phase IIb trial with more than 175 patientsDelivered180 patients, topline May 2022, within the grant period (ClinicalTrials.gov)
2. Show that RV001 prevents progressionNot achievedPrimary endpoint missed; no subgroup justified further study
3. Out-license RV001 to a large pharma companyNot achievedNo deal announced; development stopped in 2022
4. Exploratory tests in other cancersNot achievedNo such study announced by the company or listed on CORDIS
5. SafetyDeliveredNo severe adverse effects reported (CORDIS)

Scored against the grant, the result is mixed. The EU paid for a well-run, properly controlled trial, and it gave a clear answer. The answer was negative, and the commercial plan built on top of it, a licence deal ahead of Phase III, did not happen.

The Money

RhoVac funded its share of the trial mainly through a rights issue of about SEK 180.9 million in June 2019, according to the law firm Setterwalls, which advised on it, and BioStock, which also reported the EU grant as about SEK 27 million. In early 2022 the parent added a convertible loan; after the failed readout it repaid SEK 10 million of it ahead of time in August 2022 and said the rest would be paid from a tax credit and the final Horizon 2020 payment, according to a company release.

The Danish subsidiary's accounts show where the money went. RHOVAC ApS lost DKK 90.8 million in total from 2019 to 2022, the four years of the EU project, with the largest loss, DKK 33.9 million, in 2021. Its cash rose to DKK 70.6 million at the end of 2019 and fell every year afterwards.

The parent was never in the EIC Fund's portfolio: neither RhoVac nor CHOSA appears on any page of the EIC Fund's list of invested companies, which matches the grant-only award.

The Reverse Takeover

After the readout the board weighed two options: a reverse merger with another company or a solvent liquidation that would pay the remaining cash to shareholders, according to the June 2022 update and BioStock. It chose the merger. On 5 December 2022 RhoVac agreed to buy Chosa ApS for SEK 45.9 million in new shares, leaving Chosa's sellers with about 69.7% of the combined company, according to the deal announcement. Shareholders approved it on 11 January 2023, the deal closed on 18 January 2023, and Peter Buhl Jensen replaced Lars Hedbys as chief executive, according to the closing announcement. The name CHOSA Oncology AB was registered on 10 February 2023.

That makes the company a pivot rather than a closure: the listed parent and the Danish subsidiary survive, but the lead product is now Chosa's Platin-DRP biomarker and the in-licensed liposomal cisplatin LiPlaCis, not the EU-funded vaccine.

Why It Matters for Europe

Cancer is a declared EU priority. The Commission presented Europe's Beating Cancer Plan on 3 February 2021, backed by €4 billion from programmes including EU4Health and Horizon Europe, according to the Commission and Digestive Cancers Europe. A cheap injection that stopped prostate cancer from spreading would have served that plan directly, and keeping such a product in a European company was part of the rationale for funding small biotechs.

RhoVac is also a reminder of what grants of this kind buy. Phase II oncology trials fail more often than they succeed, as both the company and the CORDIS results story pointed out. The EU's €2.5 million helped produce a clean negative result in a 180-patient controlled trial, which is useful knowledge for the field, but no product, no licence and no lasting jobs.

The Verdict

This article is based entirely on public records and published statements, linked throughout. CHOSA Oncology and the EIC were not asked for comment.