Calluna Pharma

A small lab in Oslo, picking a fight with scar tissue

In a research building on Gaustadalleen in Oslo, fewer than thirty people are working on a problem that has humbled far larger companies: fibrosis, the slow, silent process by which the body's own healing turns against it. Calluna Pharma does not make a consumer product. It makes antibodies. And right now its lead one, a molecule called CAL101, is being infused into the veins of patients with scarred lungs across more than fifty clinics on four continents.

The company is named after heather - genus Calluna - a plant that colonizes burned and broken ground. It is a tidy metaphor, and unusually for a corporate metaphor, an accurate one. The whole bet here is about damaged tissue, and whether you can stop the damage from hardening into something permanent.

Most fibrosis drugs slow the fall. They don't stop it.

Idiopathic pulmonary fibrosis - IPF - is the headline example. It scars the lungs, stiffens them, and makes breathing progressively harder. There is no cure. The two approved drugs, nintedanib and pirfenidone, slow the decline but do not halt it, and many patients struggle with their side effects. Roughly three million people worldwide live with the condition. The math is grim and the market, unfortunately for everyone, is large.

The deeper problem is upstream. Inflammation and fibrosis share a trigger that the pharmaceutical industry has mostly ignored: when cells are injured, they spill proteins called damage-associated molecular patterns - DAMPs - into the spaces between cells. These molecules are alarm bells. Useful in a crisis, ruinous when they never stop ringing. Chronic DAMP signaling is how a one-time injury becomes a lifelong disease.

Two startups decided one shot was better than two

Calluna did not start from a blank page. It was assembled in January 2024 from the merger of two Norwegian biotechs, Oxitope Pharma and Arxx Therapeutics, each chasing a different DAMP. Their shared investors - Forbion, Sarsia, p53 and Investinor - decided the combined company would be stronger than either alone, and wrote a EUR 75 million Series A cheque to prove it. Forbion, a leading European life-sciences fund, led the round.

Underneath the deal sits something less fashionable than venture capital: more than thirty years of academic research into S100A4, the DAMP protein at the center of the company's lead program. Co-founder and Chief Medical Officer Jonas Hallen has been a constant through the science. In October 2024 the company brought in Mark Gaffney, a biotech operator with two decades of experience, as CEO, with Mark Altmeyer as independent board chair. The interim CEO, Forbion's John Montana, stepped back to the investor's side of the table.

Two antibodies, aimed upstream

Calluna's idea is to neutralize the alarm signals themselves rather than chase the downstream chaos they cause. Its pipeline points two antibodies at two different DAMPs.

S100A4 normally lives quietly inside your cells. It only causes trouble when injury spills it into the spaces between them, where it switches on the machinery of persistent scarring. CAL101 is built to switch that machinery back off - to "re-establish tissue homeostasis," in the company's phrasing - so the lung has a chance to stop laying down scar.

Early data, and the regulators who noticed

A Phase 1 study of 57 subjects, run by Professor Dave Singh at the Medicines Evaluation Unit in Manchester, gave Calluna the read it needed: a clean safety profile, mild-to-moderate side effects balanced against placebo, dose-dependent exposure supporting once-monthly dosing, and complete target coverage at clinically relevant doses. Encouraging, if not yet proof of efficacy. That is what Phase 2 is for.

Then the validation that matters to a small company: in October 2025 the U.S. FDA granted CAL101 Orphan Drug Designation for IPF - a status that brings development incentives and a measure of regulatory seriousness. Around the same time, AURORA finished enrolling ahead of schedule, which in clinical-trial land is roughly as rare as a quiet day in immunology.

Disrupt the disease, not just the symptom

Calluna's stated aim is to "disrupt disease progression" by targeting the upstream amplifiers of the innate immune system rather than managing the downstream wreckage. It is a deliberately unglamorous mission. There is no app, no platform, no ten-year moonshot deck - just a specific protein, a specific antibody, and a specific question about whether you can switch off scarring before it sets.

"We are encouraged by the findings from the Phase 1 study. These results are an important step forward in the development of our lead asset."

- Jonas Hallen, Co-Founder & CMO

If S100A4 is the right target, the door is wide

The reason investors wrote a EUR 75 million cheque for an antibody against one protein is that the protein shows up everywhere fibrosis does - lungs, kidneys, skin, joints, even metastatic cancer. Prove the mechanism in IPF and the same key may fit a long row of locks. That is the upside. The risk, as ever in biotech, is that biology is more stubborn than slide decks, and the Q1 2027 readout will settle the argument either way.

Back in that Oslo building, the work is unglamorous and the timeline is long. But the question on the table is a real one, and a small team is asking it carefully: not how to slow the scarring of a lung, but how to stop it. The heather, after all, does not just survive the burned ground. It grows back over it.