On Monday April 27th, the FDA held an open public meeting to discuss the scientific and ethical issues involved in developing drug treatments for children with diffuse pontine glioma.
Biopsying children with diffuse intrinsic pontine gliomas has become increasingly controversial. Clearly there are physicians that strongly hold the opinion that there will likely be no movement to cure these usually fatal tumors until tissue is obtained. Those that take this position tend to feel that the state of the art advances in neurosurgery and genomics have made it possible for DIPGs to be treated in the same way that almost all other brain tumors (as well as virtually all other cancers in the body)- with pathologic diagnosis.
This debate has gained even more attention because of a recent French trial for newly diagnosed diffuse intrinsic pontine glioma patients in which biopsy was mandatory in order to be able to participate. Of the 24 patients, all survived and two had transient neurological problems. In addition, two patients were found to have low grade tumors and were treated differently specifically because of the biopsy results. With respect to the remaining 22 high grade tumors, there was no change in therapeutic intervention as a result of biopsy.
Although there was no specific protocol or agent placed in front of the committee, the obviously increasing interest in the change of direction with this tumor caused the DIPG biopsy issue to be placed before the committee. At this time there appears to be a minimum of two or three potential US protocols on the table that include biopsy of DIPG.
It was stated that biopsies may be routinely recommended for atypical lesions. This is a clinical decision, not an ethical question.
In addition, biopsies performed as part of a determination for therapeutic intervention were also not to be part of the conversation. By definition these would be therapeutic biopsies. However, it was noted by some that the results from selecting agents based on molecular markers has been marginal in the field thus far.
The ethical question brought before the committee was:
“Assuming a reasonable expectation of scientific success, should children with DIPG undergo a non-therapeutic brain biopsy to advance the study of possible drug targets (i.e., for research purposes only)?”
References:
Stereotactic biopsy of diffuse pontine lesions in children.
J Neurosurg. 2007 Jul;107(1 Suppl):1-4
April 27th, 2009 FDA joint PAC/ODAC public meeting on DIPG Biopsy- Slides
