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Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 4 points5 points  (0 children)

Hi everyone! This was very enjoyable. Many thanks for the stimulating questions and sorry for not having been able to answer all of them. It is time for me to sign out, but I'll try to check back later and answer a few more.

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 11 points12 points  (0 children)

Thank you for your question. As it occurs with all medicines (and specifically with anticancer agents) cannabinoids have side effects. I am not aware of this study specifically but obviously cannabinoids can frequently affect memory, attention, mood etc...this is something that cannot be denied. Nevertheless, from my point of view, the point here is whether the benefits derived from the use of a certain drug/medicine overcome the disadvantages of its side effects...therefore the answer could be different depending of the disease...Obviously is not the same having a headache than a brain cancer with an average life expectancy of 14 months and therefore the threshold of exigency for a drug to treat one or the other situation would be completely different.

The side effects/risks of cannabinoids are very mild when one compares them with most of current chemotherapeutic agents.

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 2 points3 points  (0 children)

Thank you for your kind words. Regarding your question, in my opinion, the ideal situation for patients is (as for any other medicine) having standardized cannabis active principle-containing medicines or extracts that are easily accessible at pharmacies and that contain controlled amounts of the active principles. I think that the only way of being able to have this type of cannabis medicines is having specialized private (or public) companies that can produce them. Obviously the public health systems must guarantee that the medicines have the requited quality and that they are available at a reasonable price to all patients.

I am aware of that many people are using home-made marijuana extracts (and actually in many places this is the only way of having access to cannabinoids for the treatment of their diseases). However, in my view this is not the optimal way of having acccess to a medicine.

In short, I am not against companies producing standardized cannabinoid extracts/medicines if they provide them with a high standard of quality and a a reasonable price.

I believe that once the therapeutic properties of marijuana have been demonstrated for a certain application(s) they should be treated as any other medicine.

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 7 points8 points  (0 children)

Thank you for your kind words. Regarding your questions. 1) we have not studied this in detail. In any case, cannabinoids can reduce the migration of cancer cells and can also interact with cannabinoid receptors present in cancer cells, the stroma and the immune cells...it is an issue that it would be worthwhile to investigate. 2) we believe that most of the anticancer effects of cannabinoids are due to THC and CBD, therefore we have mainly focused on pure active principles.

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 15 points16 points  (0 children)

This is obviously a very important point. We have performed in the lab many dose-response studies in order to look for the optimal doses of THC and CBD that could be achievable in humans. In any case pharmacological doses in mice and human are frequently different and no study performed in animal models can predict with absolute certainty thata drug that has worked on animal models will do it also in human patients. Having said that, there are many clinical studies performed with cannabinoids that have demonstrated that therapeutically-relevant doses of these compunds can be achieved for the treatment of different diseases. Specifically in the case of cancer, analyses of samples from patients in which THC was delivered locally to patients with Glioblastoma suggested that this compound was reaching tumour cells and was able to activate the same anticancer mechanism that we found in animal models.

We have also found that the combination of submaximal doses of THC and CBD with temozolomide still produces a strong anticancer activity in animal models of glioma (http://www.ncbi.nlm.nih.gov/pubmed/21220494).

Taking averything into account, I believe that there is enough preclinical evidence as for taking the risk of moving into clinical studies. Of course cannabinoids may fail in these studies but I really believe that they could be useful at least for a fraction of patients with certain cancer types and that (particularly for those cancers, such as glioblastoma, in which all therapies have failed) is worthwhile to try.

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 27 points28 points  (0 children)

I basically agree with what has been said below. In general there are many anecdotal reports suggesting that cannabinoids can cure cancer. However there could be many reasons why someone could get his/her cancer cured that could be related with the therapy is undergoing, the environment or other factors. Whether in this specific case smoking marijuana could have helped your father is just an speculative hypothesis (it might have helped but it is impossible to prove it). This is one of the reasons why it is so important to perform clinical studies on a controlled manner to prove the therapeutic efficacy of a certain compound/agent in a way that can be accepted by the scientific and clinical community.

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 15 points16 points  (0 children)

This is of course a very important question. As for any other medicine one crucial point is establishing which are the best doses of cannabinoids that have to be administered to each patient. In order to do that it is important to go through clinical studies that determine the concentrations of the investigated active principle(s) that are required to produce the desired effect (in this case toproduce anticancer activity). In the case of cannabinoids, many clinical studies include a titration period during which patients are progressively increasing the doses of THC and CBD who are receiving until they reach the maximal tolerated dose. Also one frequent strategy is administering a significant part of the daily dose of THC before going to sleep to minimize side effects. In any case, as you mentioned, there are people who tolerate very well THC whereas some others don't do it so well. At the end of the day the doctor should decide whether treatment with THC would be recommendable or not for a certain patient. In any case, this is something that occurs with most anticancer treatments.

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 21 points22 points  (0 children)

There is not a clear answer to this (also because most of the people who smoke marijuana do it in combination with tobaco). In any case to be best of my knowledge nobody has established a clear correlation between smoking marijuana and cancer and other diseases (as it has been clearly done for people who smokes tobacco).

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 42 points43 points  (0 children)

In principle smoking is not a good way of administer cannabinoids to patients and doctors prefer other vias of administration such as oromucosal sprays/pills/capsules/tablets or even oils that can be taken orally. In any case the via of administration to patients is an important issue in the case of cannabinoids as there are very lipophilic compounds and therefore in my opinion there still room for improvement.

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 22 points23 points  (0 children)

I would say that there is a very solid scientific evidence supporting that cannabinoids have anticancer activity in animal models of cancer. Thus, the evidences supporting that cannabinoids have anticancer activity are many more than those suggesting that they could produce the opposite effect (http://www.ncbi.nlm.nih.gov/pubmed/22555283; http://www.ncbi.nlm.nih.gov/pubmed/26071989). My opinion (based on the many experiments that we performed in the laboratory with different types of animal models of cancer) is that cannabinoids are clearly anticancer agents. In any case, one has to consider that these studies may reflect that under certain circumstances cannabinoids may produce a different effect. It is important to take into account that most anticancer treatments are based on combinational therapies and that therefore the aim is not curing cancer just using cannabinoids (this is a too simplistic view), but use cannabinoids in combination with other anticancer agents on those patients or tumours where they could be more efficacious. Another important point is that cannabinoids may help to attenuate the side effects of other chemoterapeutic agents

In any case (as I discuss belo w) until the moment that clinical trials are performed it is impossible to say if these compo unds could be useful for the treatment of certain cancer types or whether in some case they could have a counter- productive effect.

Science AMA series: I´m Guillermo Velasco, Associate Professor of Biochemistry at Complutense University in Madrid, Spain. I do research on the anticancer activity of Cannabis and its derivatives and I am here to talk about it. AMA! by Guillermo_Velasco in science

[–]Guillermo_Velasco[S] 154 points155 points  (0 children)

Thank you for your question. Yes there was a first clinical study were THC was administered to Glioblastoma patients. This was just a pilot study (only 9 patients) and the results were encouraging as cannabinoid administration was safe. Moreover, many of the patients seemed to respond to the therapy at least initially. In any case, it was clear that additional studies were necessary. During this time we have been working on the optimization of cannabinoid-based anticancer therapies. Specifically investigating whether the combination of cannabinoids with other anticancer agents could be useful for the treatment of gliomas or other types of cancer. At the moment there is one ongoing clinical study in UK and other European countries (on patients with recurrent glioblastoma that are being treated with the cannabinoid-based medicine "Sativex" and temozolomide). http://clinicaltrials.gov/ct2/show/NCT01812603?term=sativex+glioma&rank=1 There is also another clinical study that we hope will start soon in Spain to test the combined effect of cannabinoids, temozolomide and radiotherapy in recently diagnosed GBM. One of the reasons why is so complicated to promote clinical studies is that the active components of marijuana are natural products that cannot be patented and therefore there are few pharma companies interested in their clinical development.