What is a xenograft?

Xenograft, (xenos- from the Greek meaning “foreign”), is the transplantation of living cells, tissues or organs from one species to another. At Xenopat, we implant small fragments of human tumors into mice.

What does orthotopic implantation mean? Why is it important?

Orthotopic means implantation of a tissue in its matching natural location in another body. In the case of Xenopat we implant the patients’ tumor in the same organ of origin. Through the orthotopic implantation effects of surrounding environment in tumor growth and development are exactly the same as they are in its original location. Orthotopic implantation is key in order to achieve the best correlation between orthoxenograft® and patients’ response to drug treatments.

What is an orthoxenograft®?

Orthoxenografts® are mouse models in which a small piece of human tumor (xenograft) is implanted in the same organ of origin (orthotopically). Orthoxenografts® are Patient-Derived Xenografts (PDXs). Xenopat offers the possibility to take a small fragment of a client tumor and implant it in a mouse in the organ of origin, generating thus its own orthoxenograft®. Orthoxenografts® are key tools to perform Personalized Cancer Treatment based on scientific evidences.

Why do I need an orthoxenograft®?

Orthoxenografts® are key tools for performing Personalized Cancer Treatment based on scientific evidence.

If you are under chemotherapeutic treatment, two scenarios can occur:

1) You are responding to chemotherapy. In this case your orthoxenograft® colony will be used to anticipate a future relapse event. The orthoxenograft® colony will be treated with the same chemotherapy you are being treated. If tumors relapse in mice, different subpopulations of the orthoxenograft® colony will be treated with alternative therapies.

2) You are not responding to the chemotherapy. If your tumor is already refractary to chemotherapy, your orthoxenograft® colony will be used to suggest the best alternative therapy for you. Different subpopulations of the orthoxenograft® colony  will be treated with alternative therapies.

In both cases, in agreement with the oncologist, a wide range of alternative treatments will be discussed. The selection of treatments to test will be based on several criteria: in market drugs, open clinical phase assays, tumor genetic properties, and tumor histology among others. The selected therapeutic approaches will be tested in different subpopulations of the orthoxenograft® colony  will be treated with alternative therapies. This procedure will allow Xenopat to find the best therapeutic alternatives available for each patient. Obtained results will be reported in an antichemogram.

If I am responding to my chemotherapy treatment, do I need an orthoxenograft®?

Yes, you do. Although you might be responding to your chemotherapy treatment, a resistance may develop in the future. By generating an orthoxenograft®, you are anticipating a possible future relapse event, which can be responsible for the failure of the clinical case. Xenopat will generate a resistant orthoxenograft® from your tumor ex vivo, that means in  mice. Your orthoxenograft® colony will initially be treated with the same first line of chemotherapy as you. If tumors relapse in mice, different subpopulations of the orthoxenograft® colony will be treated with alternative therapies. Obtained results will be reported in an antichemogram. The advantage is that you do not need to wait until your tumor relapses, Xenopat can anticipate this process, gaining very important time. Enabling you to anticipate possible future events, and hence, avoiding future complications that might arise from obtaining a tumor biopsy when the tumor relapses.

If my tumor is already chemotherapy resistant, do I need an orthoxenograft®?

Yes, you do. A chemoresistant tumor is a tumor that does not respond to chemotherapy. Although the patient is being treated the tumor keeps growing. Chemotherapy refractary cells have acquired the capacity to growth under chemotherapy conditions and thus are named resistant cells. These tumors are completely different from the primary original tumor, because resistant cells have been selected. It makes no sense to proceed with the current treatment and an alternative treatment needs to be pursued. Xenopat will generate an orthoxenograft® mice colony and different subpopulations of the orthoxenograft® colony will be treated with alternative therapies. This procedure will allow Xenopat to find the best therapeutic alternatives available for each patient. Obtained results will be reported in an antichemogram.

Which drugs will be tested in my orthoxenograft® colony?

Drugs and drug combinations to be tested in patients’ orthoxenograft® colony subpopulations will be discussed and evaluated with patients’ oncologist. Xenopat will only test drugs that are commercialy available, or available in open clinical trials. The selection of treatments that will be tested is based on several criteria: in market drugs, open clinical phase assays, tumor genetic properties, and tumor histology among others.

What is an antichemogram?

An antichemogram is a document that reports all data obtained from patients’ orthoxenograft® colony subpopulations treatments. The antichemogram summarizes the best therapeutic alternatives observed in the patients’ orthoxenografts® colony and suggests a Personalized Cancer Treatment based on scientific evidences.

Overall, how long is the Personalized Cancer Treatment process, from the tumor implantation stage to the time the antichemogram is obtained?

The Personalized Cancer Treatment process performed by Xenopat, from the tumor implantation stage to the time the antichemogram is obtained, takes between 4-8 months, depending on the tumor type and each tumors’ characteristics.

How will be my tumor sample be obtained?

Tumors need to be implanted just after surgery. Xenopat is able to implant tumors within a 24 hour window after the patient’s surgery. Later than that, the obtained tumors can no longer be implanted. In order to be suitable for implantation, tumors need to be preserved in a specific medium after surgery. The Xenopat team will get in contact with the surgery team to plan all the details of tumor preservation as well as the process of transporting it to our center.

Only a small piece of tumor is needed, hence, if surgery is not performed, tumor samples can also be obtained from a biopsy. The Xenopat team will get in contact with the biopsy team in charge of the patients operation, to plan all the details of tumor preservation and transportation to our center.

Do I need to get my surgery done in a specific hospital?

No. You can get your surgery done wherever you prefer. However, in order to be able to implant your tumor, it needs to reach our offices within 24 hours of the tumor removal. The Xenopat team will get in contact with the surgery team to plan all the details of tumor preservation and delivery.

Do all tumors received get successfully implanted? Do all tumors grow once they are implanted?

A small amount of a tumor is needed to proceed with implantation. If enough tumor is obtained, Xenopat can proceed to its implantation. Unfortunately, not all the tumors grow once they are implanted in mice. Our success rate is roughly 70-75% depending on the tumor type and size of the tumor fragment. In case the tumor does not grow, Xenopat will only charge a small  prefixed fee and return the rest of the incurred expenses.

What is the correlation between orthoxenografts® and patients response to treatments?

Orthoxenografts® are the most advanced and the best scientific tools available for predicting patients’ response to chemotherapy treatment.

What happens in the case of a tumor relapse?

In the case of a relapse, new alternative therapeutic approaches can be studied. Tumors obtained through patients’ orthoxenografts® can be cryopreserved if the customer wishes so. Cryopreserved tumors can be reimplanted in a new orthoxenograft® mice colony. This new colony will be treated following the patients’ chemotherapy schedule. After that, and in agreement with the patients’ oncologist, a wide range of alternative treatments will be tested in different subpopulations of the orthoxenograft® colony.

What is cryopreservation?

Cryopreservation is a  process that allows tissues/tumors to be preserved through time. This preservation is achieved by freezing tissues, immersed in the appropriate medium, with liquid nitrogen, reaching temperatures lower than -320 ºF (-195 ºC). Cryopreserved tissues can be defrosted and grown again. In Xenopat, cryopreservation is used to keep patients’ tumors in case that reimplantation is necessary if the patient relapses.

How can I get more information?

Do not hesitate to contact us at info@xenopat.com. The Xenopat team will be glad to answer all your questions and provide you with any information you might require.