Los resultados del ensayo preliminar muestran que la inmunización es segura y provoca una respuesta duradera
La primera candidata a vacuna preventiva contra el VIH desarrollada en España, MVA-B, ha pasado con éxito su primer corte. Los resultados a un año del ensayo clínico en fase I RISVAC02, que se llevó a cabo en los hospitales Gregorio Marañón y Clínic, de Madrid y Barcelona, han demostrado que se trata de una inmunización segura, que no causa efectos adversos destacables a quienes la reciben. Así se demuestra en dos publicaciones que recogen el estudio, Vaccine y Journal of Virology.
El padre de la criatura y director del Laboratorio de Poxvirus y Vacunas del Centro Nacional de Biotecnología (CNB, del CSIC), Mariano Esteban, ha explicado que, además de demostrar su seguridad el objetivo inicial de cualquier ensayo en fase I, la más precoz en investigación humana, la vacuna española generó respuesta inmunológica al VIH en el 90% de los 30 voluntarios sanos que la probaron. Además, el 85% de ellos la mantenía un año después.El nombre de MVA-B viene del poxvirus (MVA) que utiliza como vector para introducir en el organismo los cuatro antígenos del VIH que componen la vacuna. La B se refiere al subtipo del VIH frente al que protege, que es el más común en Europa y América.
Empezará pronto a probarse como vacuna terapéutica en seropositivos
Esteban ha explicado que la vacuna comenzó a gestarse hace más de diez años y que, antes de ensayarse en humanos, se probó con éxito primero en ratones y luego en simios. Tras agradecer a los ministerios de Ciencia y Sanidad su colaboración, así como a los hospitales que han probado su vacuna, Esteban ha recordado que se trata de un ensayo en fase I, es decir, cuyo único objetivo es demostrar la seguridad. Y en este parámetro, el éxito de MVA-B es indiscutible. El 100% de los efectos adversos relacionados con la vacunación fueron locales, como pequeño dolor en la zona del pinchazo o cefaleas de escasa consideración.Felipe García, investigador del hospital Clínic de Barcelona, ha insistido mucho en la cautela necesaria a la hora de interpretar estos resultados. "Lo que se ha visto es que la vacuna es capaz de inducir defensas; de momento no podemos saber si es capaz de proteger a las personas de infectarse", ha aclarado. Los dos parámetros que apuntan los resultados de este estudio, la seguridad y la capacidad de inducir defensas, son indispensables para que se pueda pensar en el desarrollo de la vacuna.
García ha señalado, no obstante, que la eficacia que parece tener MVA-B es "de una magnitud parecida" a los mejores prototipos de vacunas frente al VIH, otras que se están probando ya en fases mucho más avanzadas de la investigación. Entre ellas, ha destacado la que desarrollan los Institutos Nacionales de la Salud (NIH) de EEUU, que usa como vector un adenovirus tipo 5 combinado con ADN desnudo y que está en fase IIb. "Tiene unas perspectivas excelentes; de hecho, han duplicado el número de voluntarios", comentó García.
Mariano Esteban cree que en cinco años se habrá avanzado mucho
Hasta la fecha, sólo una vacuna ha demostrado reducir eficazmente el riesgo de infección por VIH. Formada por dos compuestos, ALVAC, del laboratorio Sanofi Aventis Pasteur y AIDSVAX B/E, de la ONG Global Solutions for Infectious Diseases, la inmunización que se probó en Tailandia demostró reducir en un 31% las posibilidades de infectarse en sujetos sanos, el primer resultado suficiente para hablar de eficacia de una vacuna, pero a todas luces lejano para soñar con su comercialización.La vacuna española ha demostrado, por el momento, que genera una inmunidad mucho mayor y que, además, la mantiene por más tiempo. "Tenemos un prototipo más potente que el de Tailandia", ha afirmado Esteban. El fármaco es, además, más eficaz que otras vacunas desarrolladas con el mismo vector, que han conseguido que genere respuesta inmune entre un 20% y un 25% de sus usuarios, frente al 90% de los de MVA-B. Por último, han señalado los investigadores, es capaz de activar tanto los linfocitos B como los T, prueba de su eficacia.
Próximos pasos
La pregunta lógica tras la presentación de estos buenos resultados es cuándo empezará el ensayo clínico en fase II, que es el que confirmará la supuesta eficacia del fármaco y, además, ayudará a determinar definitivamente la dosis. En este primer ensayo, los 24 voluntarios (de 30) a los que se administró la vacuna recibieron por vía intramuscular tres dosis (al inicio del estudio, a las cuatro semanas y cuatro meses después). "Para pasar de una fase I a una fase II hacen falta recursos y apoyo", ha aclarado Esteban.García ha explicado cuál sería la vía más factible de obtención de los mismos. "Estamos cerca de llegar a un acuerdo con el HIVACAT, un consorcio catalán público-privado creado específicamente para el desarrollo de una vacuna contra el sida que cuenta con el apoyo (y la financiación) de un laboratorio farmacéutico, Esteve, y de la Fundación La Caixa". El acuerdo consistiría en que el CNB cediera su patente al HIVACAT y, en ese caso, se diseñaría el ensayo en fase IIa. "La vacuna lo merece", ha recalcado García. "Estamos en una buena posición para lograrlo", ha apuntado Esteban.
El fármaco protegería contra el subtipo de VIH más común en Europa
Mientras se llega o no a esa alianza, los investigadores que han trabajado con MVA-B van a seguir estudiando el compuesto. La próxima fase será también un ensayo clínico en fase I pero, en esta ocasión, la vacuna no se probará en voluntarios sanos.En el mes de octubre, MVA-Bduplicará sus posibilidades de éxito, ya que empezará a ensayarse como vacuna terapéutica. "Los medicamentos para el control del VIH tienen que tomarse de por vida, lo que no es sostenible, sobre todo en los países más pobres", ha subrayado García, que coordinará la parte catalana del estudio. La madrileña será dirigida por Juan Carlos López Bernaldo de Quirós, investigador del hospital Gregorio Marañón de Madrid y miembro de la Sociedad Española Interdisciplinaria del Sida (SEISIDA).
Los especialistas han explicado que se va a seleccionar a 30 voluntarios seropositivos, nueve del Marañón, nueve del hospital Germans Trias i Pujol, de Badalona, y 12 del Clínic de Barcelona. Se trata de personas infectadas por el VIH que nunca han tenido bajada de defensas y que están en tratamiento estable con antirretrovirales. "Se les administrarán tres dosis siguiendo el mismo esquema que en este primer estudio; una al inicio del ensayo, otra en la semana cuarta y otra en la semana 16", ha explicado García. Dos meses después, los voluntarios dejarán de tomar su tratamiento antirretroviral y los médicos les seguirán durante seis meses, en los que se analizará el comportamiento de la vacuna y su seguridad.
"Tenemos un prototipo más potente que el de Tailandia"
García ha recalcado que muchas vacunas que se han ensayado como preventivas también se han estudiado como terapéuticas. En este campo, España también está teniendo un papel destacado.Precisamente, en enero de este año se publicaron en el Journal of Infectious Diseases los resultados de un ensayo en fase I con una vacuna fabricada con células del sistema inmune mezcladas con el VIH desarrollada por el HIVACAT. Aunque los resultados obtenidos fueron modestos, la inmunización terapéutica logró reducir de forma significativa, alrededor de la mitad, la presencia del virus en la sangre de los 12 voluntarios que la probaron.
Hoy, tras la presentación de los resultados de la primera vacuna preventiva española, los expertos han destacado el buen papel de nuestro país en la búsqueda de una inmunización contra el sida. "Es de esperar que en cinco años tengamos alguna vacuna en fase III. Nosotros desearíamos que fuera la nuestra", ha recalcado Esteban.
Fuente: Diario Público
The preliminary test results show that immunization is safe and elicits a response lasting
The first candidate HIV preventive vaccine developed in Spain, MVA-B, has successfully passed its first cut. The one-year results of phase I clinical trial RISVAC02, which took place at the Gregorio Marañón Hospital and Clinic, Madrid and Barcelona have shown that immunization is safe, does not cause remarkable adverse effects to those in receive. This is demonstrated in two publications that bring together the study, Vaccine and the Journal of Virology.
The child's father and director of the Laboratory of poxvirus vaccines at the National Center for Biotechnology (CNB, CSIC), Mariano Esteban, explained that, in addition to demonstrating its safety the initial objective of any Phase I trial, the earliest human research, the Spanish vaccine generated immune response to HIV in 90% of the 30 healthy volunteers who tested it. In addition, 85% of them held a year later.
The name comes from the MVA-B poxvirus (MVA) used as a vector to introduce into the body the four HIV antigens comprising the vaccine. The B refers to the subtype of HIV that protects against, which is more common in Europe and America.
Soon begin to be tested as a therapeutic vaccine in HIV-positive
Stephen explained that the vaccine began to be developed over ten years and, before human trials, first successfully tested in mice and then in monkeys. After thanking the Health Ministries of Science and collaboration, as well as hospitals that have tested his vaccine, Steve pointed out that it is a phase I trial, that is, whose sole purpose is to demonstrate safety. In this setting, the success of MVA-B is indisputable. 100% of the adverse effects associated with vaccination were local, as little pain in the area of puncture or headaches of little consideration.
Felipe Garcia, a researcher at the Hospital Clinic of Barcelona, has strongly emphasized the caution necessary when interpreting these results. "What we have seen is that the vaccine can induce defenses in time we can not know if it is able to protect infected people," he clarified. The two parameters indicate the results of this study, safety and the ability to induce defenses are essential so that you can think about the development of the vaccine.
Garcia noted, however, that the efficacy seems to MVA-B is "similar magnitude" to the best prototype vaccines against HIV, others are already testing more advanced stages of the investigation. Among them, stressed that developing the National Institutes of Health (NIH) of USA, which is used as a type 5 adenovirus vector combined with naked DNA and is in Phase IIb. "He has a bright prospect, in fact, have doubled the number of volunteers," Garcia said.
Mariano Esteban believes that in five years will be well
To date, only one vaccine has been shown to effectively reduce the risk of HIV infection. Made up of two compounds, ALVAC, Sanofi Aventis Pasteur laboratory and AIDSVAX B / E, of the NGO Global Solutions for Infectious Diseases, the immunization was tested in Thailand showed a 31% reduction in the chances of infection in healthy subjects, the first been enough to talk about vaccine efficacy, but clearly far to dream with your marketing.
Spanish vaccine has shown, for the moment, which generates a much greater immunity and also keeps longer. "We have a prototype more potent than that of Thailand," said Stephen. The drug is also more effective than other vaccines developed with the same vector, they have managed to generate immune response between 20% and 25% of its users, compared to 90% of MVA-B. Finally, the researchers note, is able to activate both B cells and the T, evidence of their effectiveness.Next Steps
The logical question after the presentation of these good results is when it will begin Phase II clinical trial, which is supposed to confirm the efficacy of the drug and also help to definitively determine the dose. In this first trial, 24 volunteers (30) to those who received the vaccine was administered intramuscularly three doses (at baseline, at four weeks and four months later). "To move from one phase to a phase II I need resources and support," Steve clarified.
Garcia explained what would be the most feasible way of obtaining them. "We are close to reaching an agreement with the HIVACAT, a public-private consortium Catalan created specifically for the development of an AIDS vaccine that has the support (and funding) of a pharmaceutical laboratory, Esteve, and the Foundation La Caixa ". The agreement that the CNB would give up his patent to HIVACAT and, if so, would design the Phase IIa. "The vaccine deserves it," Garcia stressed. "We are in a good position to do," he noted Stephen.
The drug may protect against HIV subtype most common in Europe
As he comes or not this partnership, researchers have worked with MVA-B will continue studying the compound. The next phase will also be a Phase I clinical trial, but on this occasion, the vaccine will be tested in healthy volunteers.
In October, MVA-Bduplicará your chances of success, which will begin to be tested as a therapeutic vaccine. "Medications to control HIV have to be taken for life, which is not sustainable, especially in the poorest countries," stressed Garcia, who will coordinate the Catalan part of the study. The Madrid will be directed by Juan Carlos Lopez Bernaldo de Quiros, a researcher at the Gregorio Maranon hospital in Madrid and a member of the Spanish Society Interdisciplinary AIDS (six).
Specialists have explained that they will select 30 seropositive volunteers, nine of the Maranon hospital nine Germans Trias i Pujol, Badalona, and 12 of the Clinic of Barcelona. These are people infected with HIV who have never had down defenses and are in stable treatment with antiretroviral drugs. "They were three dose following the same pattern as in this first study, one at baseline, one at week four and again at 16 weeks," said Garcia. Two months later, the volunteers will stop taking their antiretroviral treatment and doctors will continue for six months, which will analyze the behavior of the vaccine and its safety.
"We have a prototype more potent than that of Thailand"
Garcia stressed that many vaccines have been tested and have also been studied preventive and therapeutic. In this field, Spain is also taking a leading role.
Indeed, in January this year were published in the Journal of Infectious Diseases the results of a phase I trial with a vaccine made from immune system cells mixed with HIV developed by the HIVACAT. Although the results were modest, therapeutic immunization has reduced significantly, about half, the presence of virus in the blood of 12 volunteers who tested it.
Today, after the presentation of the results of the first Spanish preventive vaccine, experts have highlighted the great role of our country in search of an immunization against AIDS. "Hopefully in five years we have a vaccine in phase III. We wish it were our own," he stressed Esteban.
The first candidate HIV preventive vaccine developed in Spain, MVA-B, has successfully passed its first cut. The one-year results of phase I clinical trial RISVAC02, which took place at the Gregorio Marañón Hospital and Clinic, Madrid and Barcelona have shown that immunization is safe, does not cause remarkable adverse effects to those in receive. This is demonstrated in two publications that bring together the study, Vaccine and the Journal of Virology.
The child's father and director of the Laboratory of poxvirus vaccines at the National Center for Biotechnology (CNB, CSIC), Mariano Esteban, explained that, in addition to demonstrating its safety the initial objective of any Phase I trial, the earliest human research, the Spanish vaccine generated immune response to HIV in 90% of the 30 healthy volunteers who tested it. In addition, 85% of them held a year later.
The name comes from the MVA-B poxvirus (MVA) used as a vector to introduce into the body the four HIV antigens comprising the vaccine. The B refers to the subtype of HIV that protects against, which is more common in Europe and America.
Soon begin to be tested as a therapeutic vaccine in HIV-positive
Stephen explained that the vaccine began to be developed over ten years and, before human trials, first successfully tested in mice and then in monkeys. After thanking the Health Ministries of Science and collaboration, as well as hospitals that have tested his vaccine, Steve pointed out that it is a phase I trial, that is, whose sole purpose is to demonstrate safety. In this setting, the success of MVA-B is indisputable. 100% of the adverse effects associated with vaccination were local, as little pain in the area of puncture or headaches of little consideration.
Felipe Garcia, a researcher at the Hospital Clinic of Barcelona, has strongly emphasized the caution necessary when interpreting these results. "What we have seen is that the vaccine can induce defenses in time we can not know if it is able to protect infected people," he clarified. The two parameters indicate the results of this study, safety and the ability to induce defenses are essential so that you can think about the development of the vaccine.
Garcia noted, however, that the efficacy seems to MVA-B is "similar magnitude" to the best prototype vaccines against HIV, others are already testing more advanced stages of the investigation. Among them, stressed that developing the National Institutes of Health (NIH) of USA, which is used as a type 5 adenovirus vector combined with naked DNA and is in Phase IIb. "He has a bright prospect, in fact, have doubled the number of volunteers," Garcia said.
Mariano Esteban believes that in five years will be well
To date, only one vaccine has been shown to effectively reduce the risk of HIV infection. Made up of two compounds, ALVAC, Sanofi Aventis Pasteur laboratory and AIDSVAX B / E, of the NGO Global Solutions for Infectious Diseases, the immunization was tested in Thailand showed a 31% reduction in the chances of infection in healthy subjects, the first been enough to talk about vaccine efficacy, but clearly far to dream with your marketing.
Spanish vaccine has shown, for the moment, which generates a much greater immunity and also keeps longer. "We have a prototype more potent than that of Thailand," said Stephen. The drug is also more effective than other vaccines developed with the same vector, they have managed to generate immune response between 20% and 25% of its users, compared to 90% of MVA-B. Finally, the researchers note, is able to activate both B cells and the T, evidence of their effectiveness.Next Steps
The logical question after the presentation of these good results is when it will begin Phase II clinical trial, which is supposed to confirm the efficacy of the drug and also help to definitively determine the dose. In this first trial, 24 volunteers (30) to those who received the vaccine was administered intramuscularly three doses (at baseline, at four weeks and four months later). "To move from one phase to a phase II I need resources and support," Steve clarified.
Garcia explained what would be the most feasible way of obtaining them. "We are close to reaching an agreement with the HIVACAT, a public-private consortium Catalan created specifically for the development of an AIDS vaccine that has the support (and funding) of a pharmaceutical laboratory, Esteve, and the Foundation La Caixa ". The agreement that the CNB would give up his patent to HIVACAT and, if so, would design the Phase IIa. "The vaccine deserves it," Garcia stressed. "We are in a good position to do," he noted Stephen.
The drug may protect against HIV subtype most common in Europe
As he comes or not this partnership, researchers have worked with MVA-B will continue studying the compound. The next phase will also be a Phase I clinical trial, but on this occasion, the vaccine will be tested in healthy volunteers.
In October, MVA-Bduplicará your chances of success, which will begin to be tested as a therapeutic vaccine. "Medications to control HIV have to be taken for life, which is not sustainable, especially in the poorest countries," stressed Garcia, who will coordinate the Catalan part of the study. The Madrid will be directed by Juan Carlos Lopez Bernaldo de Quiros, a researcher at the Gregorio Maranon hospital in Madrid and a member of the Spanish Society Interdisciplinary AIDS (six).
Specialists have explained that they will select 30 seropositive volunteers, nine of the Maranon hospital nine Germans Trias i Pujol, Badalona, and 12 of the Clinic of Barcelona. These are people infected with HIV who have never had down defenses and are in stable treatment with antiretroviral drugs. "They were three dose following the same pattern as in this first study, one at baseline, one at week four and again at 16 weeks," said Garcia. Two months later, the volunteers will stop taking their antiretroviral treatment and doctors will continue for six months, which will analyze the behavior of the vaccine and its safety.
"We have a prototype more potent than that of Thailand"
Garcia stressed that many vaccines have been tested and have also been studied preventive and therapeutic. In this field, Spain is also taking a leading role.
Indeed, in January this year were published in the Journal of Infectious Diseases the results of a phase I trial with a vaccine made from immune system cells mixed with HIV developed by the HIVACAT. Although the results were modest, therapeutic immunization has reduced significantly, about half, the presence of virus in the blood of 12 volunteers who tested it.
Today, after the presentation of the results of the first Spanish preventive vaccine, experts have highlighted the great role of our country in search of an immunization against AIDS. "Hopefully in five years we have a vaccine in phase III. We wish it were our own," he stressed Esteban.
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