Prolactin induced increase in neural stem cell numbers

Patent Number: 7,393,830

We at StemCellPatents.com believe that the future of stem cell therapy will involve optimization of current therapeutic approaches that are already in clinical trials.  For example, it is known that intravenous administration of mesenchymal stem cells can generate statistically significant improvement in heart function after heart attacks.  It is also known that numerous neurological conditions, such as multiple sclerosis, or stroke, can improve after stem cell therapy.  But how can we magnify these therapeutic effects?  One way is to increase efficacy of homing of the stem cells to the site of injury.  Another way is to administer pharmaceutical agents that can activate the stem cells after they have been administered.  Perhaps even more exciting is simply administering agents that activate the endogenous stem cells of the patient so that one does not need to go to all of the trouble associated with administration of a cell therapy.

The concept of administering a pharmaceutical agent that would activate endogenous stem cells is not that far-fetched.  For example, if you think about it, some of the most profitable biotechnology drugs, such as erythropoietin and G-CSF, both work by modulating activity of endogenous stem cells: hematopoietic stem cells.  Now what about other types of stem cells?

In the current patent, the Canadian stem cell company Stem Cell Therapeutics, has continued its mission of developing pharmaceutical agents that activate endogenous stem cells, by obtaining a patent on the use of prolactin for this purpose.  While the company's main product NTx(TM)-265 is already in Phase IIb clinical trials for stroke, this patent will provide powerful IP support for other therapies being developed.

The patent contains 3 sets of independent claims, essentially covering the use of a prolactin for a) increasing neural stem cells; b) increasing the numbers of neurons; and c) increasing the numbers of neurons in the olfactory bulb.  Dependent claims include methods of administration, numerous agents that prolactin synergizes with, as well as treatment of numerous diseases including stroke, brain injury, multiple sclerosis, ALS, huntington's disease and parkinson's disease.  Experimental data in the examples section includes demonstration of increased neural stem cells after administration of prolactin in vitro and in vivo.

We believe this patent is uniquely positioned since after filing of the patent independent groups have reported therapeutic uses of prolactin in the area of neurology.  For example it was demonstrated that administration of prolactin accelerates remyelination.  Additionally, it was published that prolactin actually inhibits diabetes in the non-obese diabetic mouse model (Atwater et al. Pregnancy hormones prevent diabetes and reduce lymphocytic infiltration of islets in the NOD mouse. Ann Clin Lab Sci. 2002 Winter;32(1):87-92).  Given that prolactin and its family members have numerous stem cell stimulatory functions, including activity on hematopoietic stem cells, the future use of this compound will be very interesting to observe.

View this patent on the USPTO website.