When Danish biotech powerhouse Bavarian Nordic announced its cancer vaccine Prostvac was a phIII bust in September 2017, a gap opened in the Scandinavian competitive landscape of castration-resistant prostate cancer therapies. Less than a year later, Swedish micro-cap biotech DexTech Medical seems ready to fill that void as it wraps up a clinical study early, with promising data for its drug candidate OsteoDex.
An incurable disease with high business value
Every year roughly 750 000 American men are diagnosed with prostate cancer. Around 140,000 die after developing the most severe form, metastatic castration-resistant prostate cancer or mCRPC. There is no curative therapy and the unmet medical need is huge, since patients usually develop drug resistance to the handful of therapies currently available on the market.
Inevitably, the dire situation also represents a growing financial incentive for pharma companies. Especially given the fact that any promising new drug candidate within this field could be a potential blockbuster, should it reach the market. According to Datamonitor Healthcare, the total prostate cancer drug revenues in the US, Japan and five major EU markets (France, Germany, Italy, Spain, and the UK) will increase from $6.4bn in 2015 to $13.5bn in 2024 at a compound annual growth rate of 8.6%
Dextech Medical brings expertise in prostate cancer
The multi-billion dollar market for mCRPC is the primary target for DexTech Medical, a Swedish biotech company specialized in urological oncology. The Uppsala-based, SpotLight stockmarket listed micro-cap player has developed its lead drug candidate based on the proprietary platform technology GuaDex using dextran, a carbohydrate molecule, which is modified and used as the backbone when developing new candidate compounds.
– DexTech Medical
For more information on the phase IIb-study, see Clinical trials.
Preclinical results indicate broad tumor potential
OsteoDex, which is DexTech Medical’s leading drug candidate in a pipeline of four substances, gives very few and minor side effects compared to other cytostatics. This is very important as the current patient group is sensitive to treatment side effects.
DexTech’s preclinical studies have also clearly shown that OsteoDex has a potential targeting advanced breast cancer with skeletal metastases. In addition, the company has seen significant activity in soft tissue tumors, though skeletal tumors are the primary target.
European reference deals
Scandinavian analyst house BioStock has, in its coverage of DexTech, pointed out the many parallels to Xofigo, another drug targeting prostate cancer with similar qualities to OsteoDex, which was picked up by German pharma giant Bayer in 2013 when it acquired Norwegian Algeta in a $2.9B cash deal.
A more recent reference deal took place in October, when US-based Endocyte announced a billion dollar agreement with German ABX GmbH for a treatment targeting castration-resistant prostate cancer. ABX received $12 million upfront and up to 6 million Endocyte shares if all terms in the deal are fulfilled. In addition, ABX will recieve milestone payments amounting to up to $160 million and two-digit royalties on future sales.
Radioactive isotopes such as Endocyte’s and Bayer’s treatments mentioned above are not uncomplicated as a treatment option since they involve both radio-safety regulations and special departments within hospitals. Considering that they also can cause serious side-effects on both kidneys and bone marrow, there is certainly a need for drugs that show high efficacy with less side effects. Another benefit of non-radioactive drugs would be the simpler logistics, i.e. the practical handling of the substance at treatment clinics.
A benchmark between OsteoDex and Xofigo shows similarities
Bayer’s drug Xofigohas the same target as OsteoDex (CRPC). Both substances are also so-called mimetics, meaning that they mimic the binding of the natural substances to the bone. The differences between the substances in this regard are minor; Ra-223 binds to bone as calcium, while OsteoDex binds to the skeleton like Pyrophosphate, a natural substance that regulates bone mineralization. Both drugs act by breaking or inhibiting the so-called “vicious cycle”, i.e. the process where bone cells and tumor cells are mutually stimulating each other by secreting growth factors.
Similar clinical effect
The clinical effect of the two substances are also similar in that they have little or no effect on PSA (prostate-specific antigen). On the other hand, both have a pronounced effect on bone markers, substances that signal either bone breakdown or abnormal bone formation (lytic or blastic activity), such as alkaline phosphatase or ALP.
Prostate cancer have a preference to metastasize to the skeleton. Bone tissue contains two principal cells, osteoblasts that builds bone and osteoclasts that break it down. The signaling between bone cells and tumor cells stimulate progressive breakdown of normal bone and progression of the metastatic growth. This is described as “the vicious cycle”, a condition which is incurable and may at the very best be slowed down.
– Anders R Holmberg, CEO DexTech Medical
OsteoDex’s true strength could be in a combined therapy
Considering that castration-resistant prostate cancer with skeletal metastases is an incurable state, where all current therapies after some time become ineffective, the strategy for future treatments is quite possibly about finding combination regimens to maximize the benefit for the patient. Could a combo of OsteoDex and another drug on the market be the solution? – It just might be.
In theory it is feasible that OsteoDex could be the perfect match as a supplement to Xofigo. Partly because of the significant similarities between the two, and partly because the primary strength of the two drugs is that they are mimetic. While Xofigo is absorbed in the skeleton just like calcium, OsteoDex binds as pyrophosphate and is perceived by the tumor cell as a polyamine that the tumor cell needs to grow.
– Anders R Holmberg, CEO DexTech Medical
DexTech Medical hopes to repeat the Bayer/Algeta deal
While there are several recent reference deals within prostate cancer, such as the Endocyte/ABX-deal mentioned earlier or AstraZeneca‘s $2.8 billion transaction in which the commercial rights of Zoladexfor the treatment of prostate cancer were transferred to TerSera Therapeutics, there is one deal with an indirect link to DexTech Medical. When Bayer in 2013 acquired the Norwegian prostate cancer company Algeta for $2.9 billion, one of those responsible for designing the clinical trials in the development of their drug Xofigo, was Sten Nilsson, Professor of Oncology and co-founder of DexTech Medical.
And the big players in this field are continuously scouting for a more effective treatment with minimal side effects. A few of these, besides the above-mentioned companies, are Bristol-Myers Squibb, Abzena, Telix, Threshold Pharma and OBI Pharma, in which recent merger activities and licensing agreements relating to DexTech Medical’s interest area have been seen.
Collaboration with EY to find the perfect industry partner
As DexTech Medical’s phase IIb study with OsteoDex is nearing conclusion with data readout planned in the second half of 2018, the company has initiated a focused effort together with global consulting firm EY‘s biotech experts to identify appropriate industry partners. This could prove an important preparatory measure, as the Swedish biotech player heads towards the unveiling of final clinical results and efficacy data which it hopes will confirm the promising results from previous studies.
Read more about DexTech Medical here: http://dextechmedical.com/en/