Over the past two years, Xintela conducted a Phase I/IIa clinical trial in which the stem cell-based drug candidate XSTEM was tested in patients with knee osteoarthritis. The study evaluates safety and tolerability as well as preliminary efficacy signals for three different dose levels of XSTEM.
The study includes a total of 24 patients with moderate knee osteoarthritis, divided into three dose groups of eight patients each who received the treatment through an injection into the knee joint.
Disease-modifying potential
The company has now completed an interim analysis of the study, confirming good safety and positive efficacy results 18 months after treatment. No serious treatment-related adverse events were observed for any dose level.
The highest dose of XSTEM provided the best treatment response in terms of pain, knee function, and bone and cartilage structure compared to the lower doses. The results also suggest a disease-modifying potential, as the treatment also improved bone structure and showed a trend towards slowing cartilage breakdown.
– It is very encouraging that XSTEM, in addition to a strong and lasting effect on pain and joint function, also shows a therapeutic effect on bone and cartilage tissue. This shows XSTEM's potential to become a disease-modifying treatment for osteoarthritis, which is currently lacking for this very large patient group, says CEO Evy Lundgren-Åkerlund.
Reduced pain and improved ability in everyday life
The highest dose of XSTEM resulted in a statistically significant, clinically relevant and durable improvement in knee pain and knee function that persisted up to 18 months after treatment compared to pre-treatment.
Pain was reduced by 63 percent (VAS, Visual Analogue Scale) in the highest dose group 18 months after dosing. All patients in the dose group showed clinically relevant improvement in their ability to perform daily activities at 18 months compared to before treatment.
The highest dose also showed a positive effect on the subchondral bone structure by reducing osteoarthritis-related changes, while slowing cartilage breakdown.
– Interestingly, we see a difference between the doses and that the highest dose clearly gives the best effect. This shows that the treatment effect comes from XSTEM and is not a placebo effect from the injection, says Evy.
Complete the study in 2025
The company will now focus on the 24-month follow-up of the highest dose group, which is planned to be reported in September 2025. The patients who received the lower doses have already completed the study after 18 months of follow-up.
– We now look forward to completing the study with 24-month data from the highest dose level. Our results provide strong support for the next clinical steps with XSTEM that we plan to take together with a partner to accelerate the development of XSTEM to the market and to osteoarthritis patients around the world.
CEO comments on the positive results
Xintela's shares rose 37 percent on the same day the interim results were presented. BioStock contacted the company's CEO Evy Lundgren-Åkerlund to learn more about the positive news from the company.
What aspects of the study results do you think are particularly important to highlight?
– The significant and lasting reduction in pain and improvement in joint function, 18 months after treatment, truly convinces of XSTEM's strong therapeutic effect. The fact that we were also able to see an improvement in bone and cartilage structure is very encouraging and shows the potential of XSTEM to live up to our hopes of becoming a disease-modifying treatment for osteoarthritis.
– I would also like to highlight that we see a difference between the three different dose levels that were tested (4, 8 and 16 million stem cells) and that the highest dose had the best therapeutic effect in all efficacy assessments. This clearly shows that the effect comes from XSTEM and is not a placebo effect from the injection. I would also like to point out that a placebo effect, which is often seen with injectable osteoarthritis treatments, does not last for 18 months after a treatment, which clearly speaks in favor of XSTEM.
What can you say about the pain relief that XSTEM provides compared to traditional treatments, such as painkillers or cortisone injections?
– The pain relief we see from XSTEM lasts for at least 18 months, which is not achieved with other pain-relieving treatments. This is because XSTEM has multiple mechanisms of action that not only treat symptoms such as pain and inflammation but can also slow down the breakdown and stimulate the build-up of damaged articular cartilage and other tissues in the joint. I would also like to mention that repeated cortisone treatments for joint pain can have a degrading effect on articular cartilage.
What does it mean that XSTEM has disease-modifying potential in the treatment of osteoarthritis, and how does it differ from existing treatments for knee osteoarthritis?
– A treatment that has a disease-modifying effect treats the underlying cause of the disease, i.e. the breakdown of articular cartilage and other tissues in the joint and not just symptoms such as pain and inflammation. Our results from the interim analysis show that the XSTEM treatment, in addition to a significant positive effect on pain and joint function, improved bone structure and also showed a trend to stop cartilage breakdown.
– This provides support for XSTEM having a disease-modifying effect and thus a potential to become an effective treatment for osteoarthritis. Currently, there are no approved drugs that can offer patients a much-awaited disease-modifying treatment.
The study shows that the highest dose of XSTEM gave the best results – what does this mean for future study designs?
– The fact that we see differences in effect in the doses we tested is very positive. It shows that we have chosen relevant dose levels and it gives us very important information for how we will design future studies.
What are the next steps after the study is completed after the 24-month follow-up?
– We have already started planning for the next step, which will be a Phase IIb study where we will further investigate the dose for continued clinical development, compare the effect of XSTEM with placebo and likely also investigate the effect of repeated dosing. The goal is to initiate the clinical study in early 2026, either together with a partner or solely by Xintela.
You mention that you plan to take XSTEM further with a partner – what are you looking for in a collaboration partner?
– With fantastic results from the interim analysis, we are now intensifying our business development activities, with the main goal of finding a partner for continued clinical development and commercialization of XSTEM. A strong partner from the pharmaceutical industry would be valuable in accelerating XSTEM's path to market and to all osteoarthritis patients worldwide.
– We are also evaluating the possibility of self-financing the development of XSTEM through clinical phase IIb and thereby further increasing the commercial value of XSTEM before partnering/out-licensing.