Kaspar Hallsten, CIO and Portfolio Manager at Rhenman & Partners, built his analytical foundation at PricewaterhouseCoopers in financial analysis and corporate advisory before joining Rhenman & Partners, a Stockholm-based healthcare-focused investment firm. He holds a degree in finance from Stockholm Business School and supplemented it with studies in physiology at the Karolinska Institute, a combination that shapes his ability to combine medical science alongside financial models. He also competed at an elite level as a member of Sweden’s National Equestrian team. His presentation at the 2026 Sohn Monaco Conference focused on two small-cap healthcare companies with very different scientific approaches.
Different Science, Same Pattern
Hallsten opened by framing both ideas around a recurring signal he looks for in early-stage healthcare investing: when the incumbent most threatened by a new technology decides to participate in its financing rather than compete against it, that is meaningful validation of the underlying science. Both picks share that feature, and both are, in his view, early enough that the market has not fully priced what they could become.
Anteris Technologies and the Case for DurAVR
The first idea was Anteris Technologies (Nasdaq: AVR), a heart company with a market cap of approximately $900 million and net cash of $279 million. Anteris is commercializing DurAVR, a biomimetic transcatheter aortic valve designed to restore healthy-valve performance in patients with aortic stenosis.
Hallsten began with the disease. Aortic stenosis is one of the most serious conditions in cardiology. Left untreated, half of patients with severe symptomatic aortic stenosis die within two years. The first open-heart surgical procedure to address it dates to 1960. The real transformation came in 2011 with the commercial introduction of transcatheter aortic valve replacement (TAVR), which has since become the standard of care for high-risk patients and is now expanding into lower-risk and younger populations. That market is currently a duopoly shared by Edwards Lifesciences and Medtronic, and it is both large and underpenetrated: fewer than 20% of diagnosed aortic stenosis patients receive treatment today.
Hallsten sees the TAVR market growing from roughly $8 billion in 2025 to approximately $12 billion by 2028, a figure that includes the Valve-in-Valve (ViV) opportunity representing roughly 20% of the total addressable market. As the patient population expands into younger, longer-lived individuals, durability becomes the critical differentiating feature, and that is precisely where Hallsten believes DurAVR has an edge.
DurAVR is a single-piece folded leaflet design that mimics the natural geometry of the human aortic valve. Because the tissue is formed and molded as one continuous piece, Hallsten argued it enables superior hemodynamics compared to conventional multi-piece TAVR valves. It is also built on an anti-calcification tissue platform already validated in more than 55,000 patients, which provides real-world durability data that newer entrants typically cannot match.
The key trial for Anteris is PARADIGM, a head-to-head study of DurAVR against the two market leaders, Edwards and Medtronic. Full enrollment is expected by late 2026 or early 2027, with one-year follow-up data to follow. Hallsten’s base case has FDA and CE mark approval in late 2028, with commercial launch beginning in early 2029.
The validation signal Hallsten returned to most was what happened in January 2026. Medtronic, one of the two dominant incumbents in the TAVR market and therefore among those with the most to lose if DurAVR succeeds, invested $90 million in Anteris’s latest capital raise for a stake of just under 20%. In Hallsten’s framing, the company most incentivized to see DurAVR fail chose instead to be on the inside. That decision, he argued, tells investors something important about how Medtronic’s own scientists and strategists assessed the technology.
On valuation, the stock’s current price is ~$9.40 with Rhenman & Partners’ price target of $30 for 2028/29, implying upside of approximately 219%. Hallsten was equally direct about the downside: if the PARADIGM trial fails, he estimates approximately two-thirds of current market value could be lost. Key risks include enrollment pace, the binary nature of the pivotal readout, the absence of long-term durability data, and potential dilution. He was explicit that investors should conduct their own research before acting on the idea.
Nurix Therapeutics and the BTK Degrader Opportunity
The second idea was Nurix Therapeutics (Nasdaq: NRIX), an oncology-focused biotech with a market cap of approximately $1.8 billion and net cash of $482 million, plus the benefit of its Roche collaboration. Nurix was founded in 2009 as one of the first companies built around targeted protein degradation, anchored in deep E3 ligase expertise. CEO Arthur T. Sands took the company public on Nasdaq in 2020, raising approximately $240 million.
Hallsten described Nurix as a platform company, not a single-product bet. The near-term driver is bexobrutideg (bexdeg), a BTK degrader. Existing BTK inhibitors block the BTK protein, while degraders remove it entirely. It is a mechanistically different and potentially more durable approach, and Hallsten’s team tracked the space through their scientific advisory board for several years before arriving at Nurix as the best-positioned public company to capture the opportunity.
Early phase 1 data in chronic lymphocytic leukemia (CLL) showed an 83% overall response rate in heavily pre-treated patients, with a median progression-free survival of more than 22 months. Bexdeg is administered as an oral once-daily tablet. A pivotal Phase 3 trial in second-line CLL is planned to start in the summer of 2026, which Hallsten identified as the key near-term catalyst.
The Roche deal, announced in June 2026, supports the thesis. Roche paid $700 million upfront for rights to bexdeg, with total potential payments up to $2.3 billion and an equal 50/50 profit split on US sales. The global development cost split is 40/60 in Nurix’s favor. Hallsten acknowledged that some in the market interpreted the deal as eliminating a near-term acquisition premium, given that Nurix has now partnered with four major pharmaceutical companies: Roche, Sanofi, Gilead, and Pfizer. He disagreed with that reading. In his view, the deal gives Nurix enough cash to execute its clinical program fully and removes financing risk, which in a binary biotech is meaningful.
Beyond bexdeg, the pipeline extends the platform argument. Nurix estimates a combined addressable market of approximately $48 billion by 2030, spanning $18 billion in CLL, Waldenstrom macroglobulinemia, and mantle cell lymphoma, $4 billion in chronic spontaneous urticaria, and $2.6 billion in multiple sclerosis. Partnership terms already in place include $135 million with Gilead for an IRAK4 degrader, $127 million with Sanofi for a STAT6 degrader, and $75 million with Pfizer for undisclosed DAC compounds. Key upcoming catalysts include a Sanofi STAT6 update in Q4 2026, the bexdeg immunology and inflammation trial start with Roche in Q4 2026, and bexdeg follow-up data at the ASH conference in December 2026.
Hallsten contrasted this setup with how the biotech market typically prices companies. Investors tend to focus on single catalysts rather than rewarding platform depth. With Nurix, he argued the company offers both: near-term binary upside from the Phase 3 CLL readout and longer-term value from a pipeline that could ultimately support a transition from an R&D engine to a large-cap pharmaceutical company. His price target implies approximately three times current valuation by 2028.
