Newsletter Signup - Under Article / In Page
"*" indicates required fields
A couple of months ago, we covered two big funding rounds in the span of two days in radiopharma, Nuclidium’s and Actithera’s. Fast forward to today, and the field is showing absolutely no sign of slowing down; quite the contrary.
After Nuclidium and Actithera’s funding rounds on July 9 and 10, deals piled up to shape a very dynamic summer for radiopharma. Indeed, on July 28, Clarity raised $203 million via an institutional placement to pursue its clinical trials, and the day after, ARTBIO completed a $132 million series B round to advance its alpha radioligand therapies. Additionally, SERB Pharmaceutical agreed to acquire the radioimmunotherapy company, Y-mAbs, for approximately $412 million.
Let’s take a step back and assess what’s going on with radiopharma. Was this surge in investment and deals foreseeable, and how far has the field come? We asked these questions and more, to Dr. Ebrahim Delpassand, board-certified nuclear medicine physician and founder and CEO of RadioMedix, one of the more established companies in the radiopharma landscape. His company recently closed a licensing deal with Orano Med and the Pharma giant Sanofi to develop radiopharmaceuticals, more specifically, RadioMedix’s late-stage asset, AlphaMedix.
Table of contents
Radiopharma basics: How does it work?
Could you explain to our non-experts out there what radiopharmaceuticals are?
In the field, we use the word “targeted” a lot: targeted radio nuclear therapy or targeted diagnostic probe. To explain what it means, let me use the analogy of the key and the lock.
We have a molecule that can carry radioactive material to the site of the tumor: That molecule is extremely important as it is the key to reaching the tumor cells. We typically target a characteristic of a tumor, whether it’s an antigen, a receptor, or even metabolic pathways, the lock.
What we call the ligand is attached to a radioactive material, either a diagnostic probe or a therapeutic agent. Typically, gamma emitters and positron emitters are used for imaging; the positron emission tomography (PET scan) is an example.
On the therapeutic side, we have beta emitters and alpha emitters. Beta emitters are more common and are the first generation of radiopharmaceuticals. Alpha emitters are the ones we are excited about at the moment. Alpha emitters are a lot more energetic particles and have a much shorter path length to the tissue. So, it is more powerful and at the same time, more targeted. They represent the new generation of radiopharmaceuticals. We have actinium 225, which has been around for longer, and then followed by lead 212, to name only a few. All these isotopes have their own pros and cons.
In summary, a radiopharmaceutical consists of radioactive material, a ligand, and a linker to connect these two.
What is the history of radiopharma? What have been some key challenges?
We have come a long way, and we still have quite a long way to go. When we first started working with radiopharmaceuticals, supply was one of the main challenges; not all the isotopes were readily available then.
In the last 20 years, we have also learned a lot about chelation technology, how to make these linkers stable in vivo. We don’t want to use a linker that, after injection into the patient, cannot survive in the environment and lets the isotope and the ligand go their separate ways.
The specificity of the ligand is another thing we had to work on. We started with somatostatin analogs, PSMA analogs… and we had to refine these ligands to make them more specific and targeted.
I remember in the early days of radiopharma, we were already talking about alpha emitters and were aware of their potential, but availability was a challenge, as well as finding a way to handle them, finding a linker strong enough to keep them attached to the ligand.
Most of these challenges have been addressed and very much solved by the field, and we are now looking into more specific ligands and highly expressed targets in cancer cells.
Why is radiopharma gaining momentum?
Why do you think radiopharma is gaining momentum at the moment?
Yes, there has been significant attention from investors recently, and I think it’s simply because the value is truly showing now. Novartis calls radiopharma its fourth pillar of therapeutic modalities. Novartis has acquired two major drugs that have been approved in many different countries, Lutathera and Pluvicto.
So, it’s investors, but it’s also big pharma, and both feed each other’s interests. 15 years ago, radiopharma was probably not on big pharma and investors’ radars. I think the momentum is the result of how the field handled the challenges I mentioned earlier.
Concrete success in the clinic also helped in terms of credibility and showing the benefits of radiopharmaceuticals. Lutathera is a good example of that. At the time we were treating neuroendocrine cancer patients with somatostatin receptors, we had very few drugs showing a significant response, and unfortunately, the patients’ cancers were progressing. Lutathera was the first drug that showed that targeted radio-nuclear therapy is effective, and it actually led to FDA approval.
So, there is proof that radiopharma has benefits, and the new generation of alpha emitters, such as the one we are licensing to Sanofi, are showing even more promising results in terms of progression-free survival and objective response.
Awareness is one thing, but is this momentum also fueled by technological progress itself?
The field is now headed toward alpha therapy, although there are still some beta emitter projects in the pipeline. As I said earlier, alpha emitters have higher linear energy transfer and are more targeted. This causes double-strand DNA breaks, which are more lethal to cancer cells than the single-strand breaks typically caused by beta emitters. This enhanced efficacy is a factor in investor interest, but it also means that we have to pay attention to safety profiles.
Another advantage of the field is the duality of diagnosis and treatment. It’s very unique to be able to run a test drive for a treatment. As a practitioner, when I am facing a patient, considering chemotherapy, and the success rate of that treatment is 60%, I have no way of knowing if my patient is going to be among these 60%. With radiopharma, it’s different; We can image the tumor, the type of uptake of the tumor by our drug. This is the same drug, but only the isotope is different, which allows us to do imaging, and then use the same ligand, the same key, later, with a different isotope, which has a therapeutic effect to reach those targets.
Scalability and manufacturing are often flagged as challenges in radiopharma. Why is that, and how is it being addressed?
Each radiopharmaceutical isotope presents its own manufacturing challenges. For example, Actinium-225 and Actinium-227 require different production methods, and the presence of longer-lived carriers introduces additional regulatory and safety considerations. Short half-lives of certain isotopes, like Ga-68 (68 minutes) or F-18 (about 2 hours), also create logistical hurdles for labeling and distribution. That said, nuclear medicine has experience managing short-lived isotopes.
Additionally, infrastructure is expanding: new companies focused on isotope production are entering the space, and over the next three to five years, we expect enough manufacturing capacity to reliably supply both diagnostic and therapeutic radiopharmaceuticals.
What does the field look like today?
Your company, RadioMedix, was founded in 2006 and started operating in 2007. How different is it today?
Back in 2006, our challenges were not unique to RadioMedix: limited isotope access and a regulatory landscape that was unfamiliar with radiopharmaceuticals made development tricky. For instance, we often relied on radiation thresholds from external beam therapy to estimate organ exposure, even though we knew these limits didn’t perfectly apply to targeted radionuclide therapy. There was a 23 gray (unit of absorbed radiation dose) threshold that we had to respect, although we knew it didn’t apply scientifically to radiotherapy.
Over time, the field has matured. In addition to advances in isotope manufacturing, clinical validation, and investor interest, I was particularly pleased to see the FDA provide dedicated guidance for radiopharmaceuticals, acknowledging the unique aspects of our field. At RadioMedix, we recognized early on the importance of having an FDA-compliant manufacturing infrastructure, which led us to build such a manufacturing structure in north Houston. 20 years ago, FDA-compliant radiopharmaceutical manufacturing sites simply didn’t exist.
RadioMedix is among the more established radiopharma companies. Looking at newcomers, what does a successful radiopharma startup look like to you?
There are several important factors for newcomers. Number one, make sure you are scratching somewhere that is itching. What I mean is that you need to look at the unmet needs in the clinic, don’t just jump on a drug or on a combination that looks interesting. Yes, obviously, we are after innovation; we are after more potent ligands that can reach the tumor, but at the same time, it is something that our oncologists are going to use.
Second, when you look at the molecule, I think the affinity of the ligand is extremely important. Don’t compromise in that area, because if your ligand is not specific enough, and the affinity is not high enough, then the drug might be somewhat effective, but it needs to be a lot more effective than what is already available to the patients.
Finally, look at the isotope you want to use. This isotope needs to be scalable. The major difference between just the scientific academic practice versus drug development is that you need to make sure whatever you are developing at the end has commercial scalability. Is there enough of the isotope, is there enough of the ligand that will serve hundreds of thousands of patients, if not millions of patients?
RadioMedix recently partnered with a major biopharma player, Sanofi. How do these collaborations contribute to the growth of radiopharmaceuticals?
First, the involvement of these big pharma companies comes as a huge validation of the field. Beyond the positive signal it sends, it brings significant experience in the commercial launch of the drug to a field that has less experience in that area. I think it is a nice complementarity of experience too, big pharma companies don’t necessarily have the expertise in radio nuclear therapy, so it’s not just about buying an asset. They trust the potential of the modality, and they trust us to develop it.
More specifically, about our collaboration with Sanofi, it was clear they were very interested in the field. Even after our deal, they made multiple investments in the radiopharma space. To us, Sanofi’s experience in commercialization was essential as it meant the drug would reach patients sooner, which, as a physician, is very important to me.
More investment also means more competition could be drawn to radiopharma. How do you perceive competition?
We welcome competition, as in many aspects, competition is healthy. One concern I have is that I don’t want companies promising the sky and not being able to deliver. This could have a negative impact for the entire field. If a company does deliver, it’s like a rising tide, and all the boats will go higher. Similarly, if companies lack the necessary scientific rigor but still manage to bring a lot of investors around a drug that will not be successful, then the reputation of the entire field might suffer from it.
If a company comes to me for advice and I think its candidate isn’t going to make it, I flag it; abandoning a project early, when it’s not a strong candidate, can save millions. These are hard decisions, but sometimes you have to make them.
Radiopharma momentum: A blend of scientific and industry progress
Radiopharmaceuticals have come a long way, evolving from a niche, technically challenging field to one that now attracts significant investment and attention from both big pharma and investors. Overcoming early hurdles, limited isotope availability, unstable linkers, and the need for highly specific ligands has laid the groundwork for today’s momentum. Alpha emitters, dual diagnostic and therapeutic capabilities, and proven clinical successes have created tangible value, explaining the recent surge in funding and partnerships.
Yet, as Dr. Delpassand warns, the field must maintain scientific rigor; overpromising without delivering could risk a bubble that might damage its reputation. For now, radiopharma’s rise appears well-earned, grounded in real innovation and careful problem-solving, far from the dot-com bubble of the early 2000s, which was fueled by hype without products.
Concerning RadioMedix, Dr. Delpassand said he was excited about the future and the company’s pipeline. The company is planning on expanding the utilization of lead 212, as Delpassand is a firm believer in its potential among alpha emitters. Radiomedix is also looking into the treatment of hard-to-treat conditions such as brain tumors and pancreatic ductal adenocarcinoma, areas that didn’t see major progress in the last few decades, and where Delpassand sees great potential for radiopharma.
Globally, Delpassand thinks the next 10 years in radiopharma will be about finding more specific and more potent ligands. “On the isotope side, I think we reached an optimal state; I don’t think it’s getting better than alpha emitters. I think the future of the field is bright with this wave of investment and the improvement of supply chains,” said Delpassand.
Organoids in cancer research: Paving the way for faster drug development across cancer indications
