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DOI: 10.3171/2012.10.SPINE12512
Prospective study of disc repair with allogeneic chondrocytes
Presented at the 2012 Joint Spine Section Meeting
Clinical article
Domagoj Coric, M.D.,1,2 Kenneth Pettine, M.D., 3 Andrew Sumich, M.D.,1
and Margaret O. Boltes, R.N.1
1
Carolina Neurosurgery and Spine Associates; 2Department of Neurosurgery, Carolinas Medical Center,
Charlotte, North Carolina; and 3Loveland Orthopedic Clinic, Loveland, Colorado
Object. The purpose of the study was to evaluate the safety and initial efficacy of NuQu allogeneic juvenile
chondrocytes delivered percutaneously for the treatment of lumbar spondylosis with mechanical low-back pain
(LBP). NuQu is a cell-based biological therapy for disc repair. The authors report the results at 12 months of the
NuQu Phase I investigational new drug (IND) single-arm, prospective feasibility study for the treatment of LBP for
single-level degenerative disc disease (Pfirrman Grades III–IV) at L3–S1.
Methods. Fifteen patients (6 women and 9 men) were enrolled at 2 sites. Institutional review board approval
was obtained, and all patients signed a study-specific informed consent. All patients have completed a minimum of
1 year of follow-up.
Patients were evaluated pretreatment and at 1, 3, 6, and 12 months posttreatment. Evaluations included routine
neurological examinations, serum liver and renal function studies, MRI, the Oswestry Disability Index (ODI), the
Numerical Rating Scale (NRS), and the 36-Item Short Form Health Survey (SF-36).
Results. Fifteen patients were treated with a single percutaneous delivery of NuQu juvenile chondrocytes. The
mean patient age was 40 years (19–47 years). Each treatment consisted of 1–2 ml (mean injection 1.3 ml) of juvenile
chondrocytes (approximately 107 chondrocyte cells/ml) with fibrin carrier. The mean peak pressure during treatment
was 87.6 psi. The treatment time ranged from 5 to 33 seconds.
The mean ODI (baseline 53.3, 12-month 20.3; p < 0.0001), NRS (baseline 5.7, 12-month 3.1; p = 0.0025), and
SF-36 physical component summary (baseline 35.3, 12-month 46.9; p = 0.0002) scores all improved significantly
from baseline. At the 6-month follow-up, 13 patients underwent MRI (one patient underwent CT imaging and another
refused imaging). Ten (77%) of these 13 patients exhibited improvements on MRI. Three of these patients showed
improvement in disc contour or height. High-intensity zones (HIZs), consistent with posterior anular tears, were present at baseline in 9 patients. Of these, the HIZ was either absent or improved in 8 patients (89%) by 6 months. The
HIZ was improved in the ninth patient at 3 months, with no further MRI follow-up. Of the 10 patients who exhibited
radiological improvement at 6 months, findings continued to improve or were sustained in 8 patients at the 12-month
follow-up. No patient experienced neurological deterioration. There were no disc infections, and there were no serious or unexpected adverse events. Three patients (20%) underwent total disc replacement by the 12-month follow-up
due to persistent, but not worse than baseline, LBP.
Conclusions. This is a 12-month report of the clinical and radiographic results from a US IND study of cellbased therapy (juvenile chondrocytes) in the treatment of lumbar spondylosis with mechanical LBP. The results of
this prospective cohort are promising and warrant further investigation with a prospective, randomized, doubleblinded, placebo-controlled study design. Clinical trial registration no.: BB-IND 13985.
(http://thejns.org/doi/abs/10.3171/2012.10.SPINE12512)
T
Key Words • disc repair • nucleus repair • chondrocyte •
degenerative disc disease
purpose of this prospective study was to evaluate the safety and initial efficacy of NuQu allogeneic juvenile chondrocytes (ISTO Technologies)
he
Abbreviations used in this paper: DDD = degenerative disc
disease; ECM = extracellular matrix; GAG = glycosaminoglycan;
HIZ = high-intensity zone; IND = investigational new drug; LBP
= low-back pain; NRS = Numerical Rating Scale; ODI = Oswestry
Disability Index; SF-36 = 36-Item Short Form Health Survey; TDR
= total disc replacement.
J Neurosurg: Spine / November 9, 2012
delivered percutaneously for the treatment of patients
with mechanical LBP due to lumbar DDD.
The diagnosis and treatment of mechanical or discogenic LBP due to lumbar DDD remains challenging.
Patients typically present with a history of chronic LBP
exacerbated by simple activities such as walking, standing, or prolonged sitting. Clinical examination is generally nonfocal. Characteristic radiographic findings include
loss of T2 signal in the disc and Modic endplate changes
1
D. Coric et al.
on MRI, as well as endplate sclerosis and loss of disc space
height on CT. Additional diagnostic workup, including
provocative discography, remains controversial.13,15 The
vast majority of LBP is self-limited or successfully treated with nonsurgical management. Lamentably, a small,
but significant, proportion of patients develop chronic,
intractable LBP recalcitrant to nonsurgical treatments.
This patient population utilizes significant health care resources, including chronic, long-acting narcotic therapy,
and multiple invasive procedures, such as epidural steroid
injections and facet rhizotomy. Additional economic impact includes exclusion from the workforce of a younger,
otherwise healthy patient population.12,13,17,37,53
The intervertebral disc is a fibro-cartilaginous structure without a direct blood supply.32,58 The disc consists
of 2 parts. The outer anulus fibrosus, with scant fibroblast
cells and laminated Type I collagen, provides tensile
strength. The inner nucleus pulposus, with chondrocytic
cells and randomly organized Type II collagen, resists
compressive forces.3,38 The primary blood supply to the
disc is from capillaries from the adjacent vertebral bodies that penetrate the subchondral bone terminating in
the cartilaginous endplate. Disc cells depend on passive
diffusion for nutrient supply (glucose and oxygen) and
waste removal (lactic acid).32,42,48,58 Therefore, these native disc cells survive in a relatively harsh biochemical
environment of both low glucose and oxygen tension as
well as high lactic acid (low pH).3,35,47,48 Furthermore,
these cells are subjected to substantial biomechanical
forces of the load-bearing intervertebral disc space. The
chondrocytic cells of the nucleus produce ECM consisting primarily of proteoglycans within a Type II collagen
scaffolding. Aggrecan and versican, the largest and most
common proteoglycans found in the disc, are hydrophilic
molecules with protein stems surrounded by highly negatively charged GAG side chains. Chondroitin sulfate and
keratin sulfate are the 2 most abundant GAG side chains
that attract and hold water molecules. Disc degeneration
or injury with concomitant endplate sclerosis and loss of
anular integrity compromise the native disc cell’s ability
to produce and maintain ECM. The subsequent loss of
proteoglycans and their GAG side chains results in disc
desiccation, with increased load on surrounding structures, ultimately contributing to the characteristic radiographic findings of DDD that include loss of disc height,
anular tears, endplate changes, and disc desiccation or
“black disc disease.” In a certain segment of the population, these structural findings are manifested clinically as
LBP. In this scenario, DDD can be conceptualized as the
ultimate consequence of the chondrocytic disc cell’s inability to produce and maintain the ECM.3,10,11,38,41,52
Surgical procedures focused on addressing nucleus
pathology can be broadly categorized into 3 distinct areas: nucleus replacement, nucleus augmentation, and
nucleus repair (Fig. 1). There are currently no FDA-approved devices/drugs in any of these categories. Nucleus
replacement involves surgical removal of nucleus tissue
followed by device placement, generally elastomeric
(Prosthetic Disc Nucleus [PDN], Raymedica) or mechanical (NUBAC, Pioneer Surgical Technology).5,19 Nucleus
augmentation involves adding material, either biologically inert (silk/elastic polymer, NuCore, Spine Wave)6 or
2
biologically active (fibrin sealant, Biostat Biologix) to the
disc.16,58,61 Nucleus repair procedures can be divided into
3 broad categories: growth factor therapy, gene therapy,
and cellular therapy.23,63 Growth factor therapy involves
injection of an exogenous protein to increase the native
chondrocytic cell’s ECM production by upregulating the
production of anabolic factors or downregulating catabolic factors.43,63 Gene therapy involves the transfer of genetic material to boost the disc’s native chondrocytic cell
production of ECM.16,39,41,56,59,62 Tissue-engineered cellular therapy has focused on chondrocyte1,2,36 and stem cell
replacement therapy.29,49,57,60
Traditionally, surgery for the patient population with
debilitating LBP has been reserved as treatment of last recourse and has involved fusion of the presumed diseased
segment. Fusion approaches have varied and evolved over
the years but generally consist of major spinal reconstructive procedures, such as interbody fusion (anterior, posterior, and lateral), designed to structurally remove the
pathological disc.37,46,53 Minimally invasive techniques
have been developed in an attempt to decrease operative
morbidity, but these procedures still involve loss of function of the motion segment, with concomitant increased
stresses on adjacent levels. The increased rate of degenerative changes and adjacent-level breakdown after surgical fusion is well characterized.4,20,22,28,30,40,55 Total disc
replacement was developed to address this shortcoming
but still represents a major operative procedure that removes the nucleus and the majority of the anulus.7,8,21,34,66
Intuitively, these spinal reconstructive procedures should
be reserved for advanced DDD. Disc repair procedures
offer a less invasive, biological alternative to arthrodesis
or TDR in an attempt to address LBP associated with
DDD earlier in the degenerative cascade. NuQu allogeneic juvenile chondrocyte treatment is an investigational
cellular therapy delivered via an outpatient, percutaneous
procedure under fluoroscopic guidance utilizing local anesthetic.
Methods
Patients with single-level, symptomatic lumbar DDD
from L-3 to S-1 and medically refractory LBP were prospectively treated at 2 institutions (Carolina Neurosurgery and Spine Associates, Charlotte, NC, and Loveland
Orthopedic Clinic, Loveland, CO) as part of an FDAregulated IND feasibility trial (clinical trial registration
no.: BB-IND 13985). Inclusion and exclusion criteria are
listed in the Appendix. Institutional review board approval was obtained at both institutions, and all patients
provided informed consent. Magnetic resonance imaging
was used to confirm single level (Pfirrmann Grades III
and IV) DDD at L3–S1.50 Discography was used to ensure anular integrity (Fig. 2).
Patients were evaluated using pre- and postprocedure
serial neurological examinations, pain/function questionnaires, and the SF-36 at 1, 3, 6, and 12 months. The neurological examination evaluated motor strength, sensory
function, and reflexes. Pain and function were assessed
using the ODI25 and the NRS.18 Health-related quality of
life was measured using the SF-36. A patient’s perception
J Neurosurg: Spine / November 9, 2012
Prospective study of disc repair
Fig. 1. Chart showing the intradiscal surgical treatment options.
of improvement was measured using the self-reported
health transition item of the SF-36. These outcome measures were completed by the patients without assistance.
The quantitative change in NRS, ODI, and SF-36 outcome measurements between baseline and 12 months was
determined, and significance levels were computed based
on the paired t-test. Magnetic resonance images were obtained preprocedure (Fig. 3), and results were compared
at 1, 6, and 12 months postprocedure (Fig. 4) by an independent radiologist. Adverse events were monitored and
reported to an independent data safety monitoring board
to evaluate safety of the NuQu cell therapy as well as the
treatment procedure.
Preparation of Investigational Product for Injection
culture to determine ≥ 75% viability. Furthermore, bench
testing was used to determine that cell viability was unaffected throughout treatment preparation and injection.
Procedure
All procedures were done on an outpatient basis with
a local anesthetic. The treatment level was localized, and
a 6-in, 22-gauge needle was placed in the center of the
disc space under fluoroscopic guidance (Figs. 6 and 7).
Results
Patient Population
Fifteen patients (6 women and 9 men) were treated
Allogeneic juvenile chondrocyte cells were harvested from the articular surface of cadaveric donor tissue
and expanded in vitro as previously described.1 To expand the primary allograft juvenile chondrocyte population, a cell suspension was created and inoculated into
culture flasks containing expansion medium (chemically
defined complete serum-free medium containing gentamicin, l-glutamine, growth factors, and l-ascorbate).
Fresh medium was added every 3–4 days, and the cells
were harvested after 2 passages, yielding approximately 8
population doublings (Fig. 5). Chondrocytes were washed
and counted before cryopreservation in a controlled rate
freezer at a density of 5 × 107 cells/ml. Immediately prior
to use, cells were rapidly thawed and combined with commercial fibrinogen and thrombin to yield a dose of viable
cells of approximately 107/ml.
Confirmation of Cell Viability
All treatment cells were sourced from a single qualified and released lot originating from a common pool of
suspended cells. This single lot was aliquoted into individual vials and cryopreserved. Lot release testing was
performed on a representative sample of vials according
to an approved sampling plan. Functional assays were
performed, which included cell viability after thaw that
was required to meet or exceed a minimum number of
viable cells for the lot to be released. In addition, the persistence of viable cells was further confirmed in a 45-day
J Neurosurg: Spine / November 9, 2012
Fig. 2. Postdiscogram sagittal CT.
3
D. Coric et al.
Fig. 3. Preprocedure T2-weighted MRI study showing single-level
DDD at L5–S1 with posterior HIZ.
at 2 investigational sites with a single delivery of NuQu
juvenile chondrocytes (2 L3–4 levels, 1 L4–5 level, and
12 L5–S1 levels; 12 levels at Pfirrmann Grade III and 3
levels at Grade IV). The mean patient age was 40 years
(range 19–47 years). Fourteen (93%) of the 15 patients
completed a minimum of 1 year of follow-up.
Discography
Provocative discography was not required for study
eligibility, but discography was used to ensure anular
integrity (anular rupture with dye extravasation was an
exclusion criteria). No patient exhibited extravasation of
dye into the epidural space. All 15 patients showed concordant pain at the study level.
Procedure
Each treatment consisted of a 1- to 2-ml injection
4
Fig. 4. Postprocedure T2-weighted MRI study showing improvement
in posterior HIZ.
(mean injection volume 1.3 ml) of juvenile chondrocytes
(~ 107 cells/ml) with fibrin carrier. The mean peak pressure during treatment was 87.6 psi. The treatment time
ranged from 5 to 33 seconds.
Clinical Indices
The mean ODI (baseline 53.3, 1-month 27.6, 3-month
27.1, 6-month 26.9, and 12-month 20.3; p < 0.0001) (Fig.
8), NRS (baseline 5.7, 1-month 3.9, 3-month 3.5, 6-month
3.8, and 12-month 3.1; p = 0.0025) (Fig. 9), and SF-36
physical component summary (baseline 35.3, 1-month
40.0, 3-month 43.1, 6-month 43.7, and 12-month 46.9; p
= 0.0002) (Fig. 10) scores were all significantly improved
from baseline. The SF-36 mental component summary
(baseline 48.5, 1-month 50.5, 3-month 51.1, 6-month
49.1, and 12-month 50.5) scores were improved, but not
J Neurosurg: Spine / November 9, 2012
Prospective study of disc repair
Fig. 5. Juvenile chondrocytes undergoing colony formation during
expansion under defined conditions.
significantly changed (p = 0.64) from baseline (Fig. 11).
Thirteen (92.9%) of the 14 patients showed at least 30%
improvement on the ODI. At 12 months, 8 patients (57%)
showed improvement on the health transition item of the
SF-36 (6, much better; 2, somewhat better), 4 patients
(29%) were unchanged, and 2 patients (14%) were worse
(0, much worse; 2, somewhat worse).
Radiographic Findings
At the 6-month follow-up, 13 patients underwent
MRI, 1 patient underwent CT scanning, and 1 patient
refused to undergo imaging. The MRI studies were reviewed and graded by a neuroradiologist independent of
the study investigators. Ten (77%) of 13 patients who underwent follow-up MRI showed improvements, with 3 of
these patients showing improvements in disc contour or
height. Three patients (23%) showed no changes on MRI
and 1 (8%) showed further deterioration in signal change
intensity. High-intensity zones, consistent with posterior
anular tears, were present at baseline in 9 patients. Of
these, the HIZ was either gone or improved in 8 patients
at the 6-month follow-up. Six of these patients (67%) with
HIZs were improved by 1 month. Two additional patients
showed improvements by 6-month imaging (87% total
imaging improvement by 6 months). The 1 remaining
patient with HIZ showed improvement at 3-month imaging, but this patient did not undergo further MRI follow-up.
Adverse Events
No patients experienced neurological deterioration.
There were no disc infections, and there were no serious or unexpected adverse events. There was no observed
immunological response to the chondrocyte procedure.
Postprocedure laboratory examinations included serum
chemistry as well as liver and renal function tests. Three
patients (20%) underwent TDR at 7, 11, and 12 months
postprocedure. All surgeries were for persistent, but not
worse than baseline, LBP.
J Neurosurg: Spine / November 9, 2012
Fig. 6. Anteroposterior plain radiograph showing the chondrocyte
injection procedure.
Discussion
In general, the major advantage of disc repair procedures is the ability to address the source of mechanical
LBP in select patients with DDD in a minimally invasive
fashion. Although the vast majority of patients with LBP
do not require surgical consideration, there is a small, but
significant, percentage of patients who are ultimately debilitated by their symptoms.14,17,37,53 Each of the 3 biological disc repair therapies (growth factor, gene, and cellular) has unique strengths and challenges.9,23,35,54,64
Grow factors are small peptide cytokines with cell
regulatory function. Anabolic growth factors (transforming growth factor–b, insulin-like growth factor–1,
epidermal growth factor, platelet-derived growth factor,
and bone morphogenetic proteins) increase cellular activity and ECM synthesis. Catabolic growth factors (interleukin and tumor necrosis factor) inhibit synthesis of
the ECM and may contribute to pain. Clinical research
has focused on direct administration of anabolic factors
or catabolic antagonists to boost cellular proteoglycan
production. Bone morphogenetic protein–7 (osteogenic
protein–1) and bone morphogenetic protein–14 (growth/
differentiation factor–5) have been used in clinical trials.
Practical clinical use of growth factors for a chronic disease process such as DDD, which develops over a period
of years and decades, may be limited by their relatively
short biological half-lives (hours or days)23,63 and by the
fact that chondrocytic cells of the adult nucleus undergo
senescence, potentially leaving them unresponsive to exogenous growth factors.31
Gene therapy has the ability to induce long-term
changes in anabolic growth factors and catabolic cyto
kines and, ultimately, proteoglycan production.16,23,39,41,56,
59,62
Gene therapy functionally requires vectors, either viral or nonviral, to transfer genetic material into host cells.
Viral vectors are most efficient for rapid gene transfer. Viral vectors can be of an integrating type (for example, ret5
D. Coric et al.
Fig. 8. Graph showing the mean ODIs at the different time points.
Fig. 7. Lateral plain radiograph showing the chondrocyte injection
procedure.
rovirus), generally used in transduction of dividing cells
(mitotically active cells), or of a nonintegrating type (for
example, adenovirus), effective in transducing nondividing cells (such as the adult chondrocytic cell). Since gene
therapy involves the active transfer of genetic material,
generally utilizing a viral vector, there is some inherent
risk of mutagenicity or native immune response.9,16,24,35,41
Therefore, gene therapy may be more appropriate for
potentially life-threatening disorders. Conversely, gene
therapy may, at least initially, play a more limited role in
chronic, non–life threatening disorders, such as arthritis
or lumbar DDD.9,23,24
Cellular therapy involves the introduction of exogenous disc cells, nondisc chondrocytes, or undifferentiated stem cells to augment or replenish nucleus cells that
produce ECM. Some anatomical factors favorably predispose the disc to cellular therapy. The nucleus is contained
by the anulus and has a limited blood supply, constraining cell migration and providing a relatively immunologically privileged environment.2 Conversely, transplanted
cells must deal with the same limited blood supply and
mechanically stressful environment that initially led to
loss of native chondrocytic cell loss and decreased ECM
production.3,11,35,48 Therefore, cell therapy must be instituted relatively early in the degenerative cascade prior to
advanced DDD with concomitant endplate sclerosis and
extensive anular degeneration.23,54 Animal studies have
demonstrated that allogeneic juvenile chondrocytes have
the potential to synthesize ECM and to survive in the disc
space.1,36 Recently, Acosta and associates1 showed persistence of allogeneic nondisc-derived male chondrocytes in
female pigs at 12 months. Furthermore, they reported that
6
the newly synthesized ECM was distinctly different in its
composition compared with the native nucleus and discs
receiving fibrin carrier alone.
An inherent difficulty with any surgical treatment for
mechanical LBP due to lumbar DDD involves the reliable identification of the pain generator. In the case of
surgical arthrodesis, it is necessary to identify the appropriate level(s) to be treated. Interbody fusion obliterates the majority of the disc, and the concomitant loss
of motion removes stresses from the facet joints. More
specificity is critical to the success of lumbar arthroplasty
procedures, such as TDR and nucleus replacement. In the
case of TDR, although the majority of the disc, both the
nucleus and the anulus, is removed, success of the procedure is also reliant on normal facet function. Nucleus
replacement is dependent on anular integrity as well as
normal function of the facet joints. Nucleus repair procedures are even more reliant on the specificity of diagnosis
and integrity of the surrounding structures, including the
anulus and posterior elements. Therefore, nucleus repair
is ideally suited for patients earlier in the degenerative
cascade prior to significant anular or facet disease or multilevel disease. Consequently, patient selection in the current study was limited to single-level, early DDD, which
is reflected by Pfirrmann Grade III or IV on MRI. Patients with a Pfirrmann grade of I–II or V would represent a patient population either too mild or too advanced
in the disease process to show measurable improvement.
Patients with mild to moderate DDD would be expected
to be younger and more active and would theoretically
be ideally treated using a minimally invasive approach
that preserves the motion and function of the disc. A less
invasive approach minimizes iatrogenic morbidity while
maintaining multiple revision options. The minimally invasive nature of nucleus repair procedures is reflected by
the fact that all patients in the current study were treated
on an outpatient basis with an average stay of less than
2 hours. The hospital stay in the Charité Investigational
Device Exemption study was 3.7 days for TDR and 4.2
days for anterior lumbar interbody fusion. The hospital
J Neurosurg: Spine / November 9, 2012
Prospective study of disc repair
Fig. 9. Graph showing the mean NRS scores at the different time
points.
stay in the ProDisc-L Investigational Device Exemption
study was 3.5 days for TDR and 4.5 days for anterior/
posterior fusion.8,27,66
Ultimately, the success of any procedure or device
is predicated on the clinician’s ability to accurately diagnose the underlying disease entity. The multifactorial
nature of mechanical LBP, as well as our limited diagnostic ability to identify a specific pain generator for DDD,
makes this disease entity particularly difficult to treat.
These challenges have created controversy with some clinicians arguing to limit surgical treatment of mechanical
LBP13,14 and others advocating surgery in select, medically refractory cases.26,37,46,51,53 Intuitively, the key to improving outcomes does not lie in abandoning treatment
efforts but instead in continued research, especially studies producing Level I and II data, to improve diagnosis
and broaden therapeutic options. Biological disc repair
represents a minimally invasive and motion-preserving
treatment modality to address early lumbar DDD.
There has been extensive basic research and animal
studies investigating disc repair, but there has been a paucity of human studies. Recently, Yoshikawa et al.65 reported on 2 patients treated with expanded iliac crest–derived
mesenchymal stem cells. Orozco et al.49 published a pilot
series of 10 patients with chronic LBP also treated with
expanded iliac crest–derived mesenchymal stem cells.
These authors reported clinical improvement comparable to TDR and fusion studies. Meisel and associates44,45
reported an interim analysis of 28 patients as part of a
larger prospective, randomized trial comparing standard
discectomy with discectomy followed by injection of autologous cultured disc–derived chondrocytes (Eurodisc
Study). In that study, 12 patients underwent discectomy
with harvest of autologous disc chondrocytes that were
subsequently expanded in culture and reinjected into the
disc space after 12 weeks. The preliminary results were
promising, with postdiscectomy patients treated with autologous chondrocytes showing greater pain reduction at
the 2-year follow-up.45 Evans et al.24 questioned the potential efficacy as well as the practicality of utilizing adult
autologous disc cells for nucleus repair.
J Neurosurg: Spine / November 9, 2012
Fig. 10. Graph showing the mean SF-36 physical component summary scores at the different time points.
The chondrocytic cells in the present study were implanted in previously unoperated discs and were of allogeneic origin, avoiding the difficulties associated with
autograft harvest. Moreover, these cells are derived from
juvenile sources, maintaining an increased capacity to
synthesize ECM compared with adult cells.2 The choice
of chondrocyte dose injected in the present study was
based on the normal concentration of chondrocytic cells
in the human adult disc as well as the expected viability
of chondrocytes after injection. Several researchers have
suggested that adult disc cell density is between 4 and 8 ×
106 cells/ml.33,42,47 Furthermore, Horner and Urban33 have
postulated that the cell density will self-regulate depending on nutritional supply. Given the 1- to 2-ml injection
volume and an expected 90% postinjection cell viability,
the anticipated number of cells delivered to the disc will
range between 6.75 and 13.5 × 106 cells/ml, approximating the cell density of the normal adult disc.
The clinical results in the present study showed statistically significant improvements from baseline on all
clinical scales (ODI, NRS, and SF-36). Overall, 93% of
patients showed at least 20% improvement in ODI scores,
comparable to disability improvement in both arms of the
Fig. 11. Graph showing the mean SF-36 mental component summary scores at the different time points.
7
D. Coric et al.
ProDisc-L IDE trial (minimum 15% ODI improvement:
ProDisc-L 79.6%, fusion 68.9%).66 Furthermore, the mean
ODI improvement in the present study was nearly 60% at
12 months. Safety was also demonstrated in the present
cohort. No patient experienced neurological deterioration. There were no disc infections, and there were no
serious or unexpected adverse events. Laboratory studies
indicated that there was no immunological response to
the chondrocyte treatment. Three patients ultimately did
undergo total disc replacement between 6 and 12 months
after the chondrocyte procedure for persistent, but not
worse than preprocedure, LBP. Conventional nonsurgical
therapy had failed in all 3 patients, and they presented to
surgical practices seeking surgical intervention for their
recalcitrant LBP. Although there is no nontreatment comparator group in this Phase I feasibility study, it should
be noted that previous nonsurgical therapy had failed in
all patients, including nonsteroidal antiinflammatory and
narcotic pain medications, physical therapy, and epidural
injections. Eight patients attempted nonsurgical treatment
for multiple years (4 for approximately 1 year, 2 for 8–9
months, and 1 for 4 months). The preprocedure morbidity of this patient population is reflected by the relatively
high baseline disability (ODI 53.3) and pain (NRS Score
5.7) scores comparable to the baseline disability and pain
scores of patients in the Charité and ProDisc-L Investigational Device Exemption surgical trials.8,27,66 Conversely,
the previously discussed stem cell cohort reported by
Orozco and associates49 presented with a baseline ODI
of 25.
This is the first clinical report of the results from a
US IND study of cell therapy in disc repair. The results
of this prospective study are promising. However, this is
a preliminary study without a control group and with a
relatively small number of patients. Further investigation
with a prospective, randomized, blinded, placebo-controlled study design is necessary and warranted.
Conclusions
This is the 12-month report of the clinical and radiographic results from a US IND Phase I study of cell-based
therapy (juvenile chondrocytes) for the treatment of lumbar DDD with mechanical LBP. Preliminary safety was
demonstrated, and clinical results were encouraging, with
statistically significant improvements in ODI, NRS, and
SF-36 scores. The majority of radiographic parameters
were unchanged; however, there was improvement in 10
of 13 patients who underwent imaging at 6 months and
in 8 of 13 patients who underwent imaging at 12 months.
Improvements were primarily seen in HIZ, which appeared to correlate with improvements in clinical indices.
Further study into the diagnosis and treatment of LBP
due to lumbar DDD is warranted.
Appendix: Inclusion and exclusion study criteria
Inclusion Criteria
1. Have provided consent by signing the institutional review
board–approved informed consent;
8
2. Are male or female between the ages of 18 and 70 years;
3. If female, must have a negative pregnancy test at the time
of treatment, be actively practicing contraception or abstinence, be
surgically sterilized, or be postmenopausal;
4. Have central LBP aggravated by movement and or postural
changes (standing/sitting);
5. One Grade III or IV (Pfirrmann scale) lumbar disc without
anular rupture;
6. Have tried and failed at least 12 weeks of conservative
management as directed by a licensed physician, chiropractor, and/or
physical therapist. Treatment must include any or a combination of
physical therapy, chiropractic care, or pain management. This may
include, but is not limited to, rest or activating physical therapy, heat,
cold, electrical stimulation, ultrasound, manipulation, acupuncture,
analgesics including narcotics (with no history of abuse), antiinflammatory medication, radiofrequency treatments, and spinal injections,
including epidural steroid and or anesthesia injections;
7. Have been offered and have refused, for the duration of
the clinical trial, the treatment alternatives of systemic steroid use,
epidural and spinal injection of any kind, nerve ablation, and surgical intervention;
8. Have agreed to refuse participation in another clinical trial
for the duration of this study and
9. Score on the NRS of 4–8 and/or ODI ≥ 40%.
Exclusion Criteria
1. More than one Grade III or IV (Pfirrmann Scale) disc in
the lumbar spine;
2. A Grade V (Pfirrmann Scale) disc at any level in the lumbar spine;
3. Current disc extrusion at any level in the lumbar spine;
4. Severe disc narrowing (≥ 50% loss of disc height at the
targeted level);
5. Disc bulges or protrusions at any level in the lumbar spine
resulting in radiculopathy;
6. Type II or III Modic changes at any level;
7. Type I Modic changes at any level other than the targeted
level;
8. Type I Modic changes at the treated level if the maximum
height of the changes is 25% or more of the vertebral body height;
9. Osteoporotic compression fracture at any vertebral level;
10. Lumbar Scheurmann disease or an endplate abnormality at
the targeted level;
11. Anterolisthesis or retrolisthesis ≥ 3 mm at any level;
12. Moderate to severe or worse facet disease at any level of
the lumbar spine;
13. Facet effusion at any level of the lumbar spine;
14. Moderate or severe central canal stenosis, Grade II or III
lateral recess stenosis, or foraminal stenosis at any level;
15. Spondylolysis or instability at any level;
16. Lumbar coronal angulation ≥ 10°;
17. Cauda equina syndrome;
18. Extradiscal extravasation of contrast on discogram;
19. Accepts < 1 ml of contrast on discogram;
20. Previous spine surgery or other invasive treatment of the
study disc, with the exception of previous epidural steroid or anesthesia injection;
21. Currently enrolled or have participated in another clinical
trial for the treatment of intervertebral disc disease, or received a
study drug or investigational biological agent for the treatment of
intervertebral disc disease within the last 6 months;
22. Participating or have participated in any another clinical
study in the last 3 months;
23. Currently experiencing chronic pain generating from any
other source that (in the judgment of the investigator) may interfere
with the evaluation of back pain, and or back pain related disability
and/or physical well being;
24. Radicular pain (as evidenced by nerve root tension signs)
and/or radiculopathy;
J Neurosurg: Spine / November 9, 2012
Prospective study of disc repair
25. Infection at the planned treatment site;
26. Exposure to TISSEEL within the previous 12 months;
27. Exposure to aprotinin (Trasylol) within the previous 12
months;
28. Allergy or hypersensitivity to aprotinin;
29. Allergy or hypersensitivity to radiocontrast medium;
30. BMI ≥ 40;
31. Pregnant or breastfeeding;
32. Currently diagnosed with immunodeficiency of any cause;
33. Receiving any immunosuppressant therapies;
34. History of frequent infections, active infections, or recent
infections (within 1 month prior to anticipated date of dosing);
35. Taking anticoagulants other than low-dose aspirin, or have
other known bleeding diatheses;
36. Diagnosed with any uncontrolled comorbid disease including AIDS, diabetes, hepatic or renal disease, and cardiopulmonary
disorders such as chronic obstructive pulmonary disease, myocardial
infarction, and chronic heart failure;
37. Active malignancy or history of malignancy (except basal
or squamous cell cancer that has been fully excised);
38. Abnormal urinalysis, complete blood count, or serum
chemistry judged to be clinically significant by the investigator and/
or Data Safety Monitoring Board;
39. Significant illness (including metastasis of any type);
40. Substantial risk for need of organ transplantation;
41. Those who are judged by the investigator to have an
exaggerated pain and/or behavioral response during and/or after
discography;
42. Those who use illegal drugs as evidenced on urine drug
screening;
43. History of alcoholism, medication, or drug abuse within the
last 5 years, or presently consuming alcohol in excess of 14 drinks
per week (a drink is defined as 360 ml of beer, 120 ml of wine, or
30 ml of hard liquor);
44. Those with scores in the “Distressed” category on the
Distressed and Risk Assessment Method, has a history of psychosis,
or has any of the following: a personality disorder, poor motivation,
emotional or intellectual issues including exaggerated or unreasonable behavioral response to pain that would likely make the candidate unreliable for the study, or any combination of these variables
in the investigator’s judgment that should exclude a candidate and
45. Those for whom MRI is contraindicated.
Disclosure
Drs. Coric and Pettine were principal investigators for the IND
study and received research funding and travel reimbursement from
the study sponsor ISTO Technologies. Dr. Coric is also a consultant
for Medtronic, Spine Wave, and Pioneer Surgical and owns stock in
Spinal Motion, Spine Wave, and Pioneer Surgical.
Author contributions to the study and manuscript preparation
include the following. Acquisition of data: all authors. Analysis and
interpretation of data: Coric. Drafting the article: Coric. Critically
revising the article: all authors. Reviewed submitted version of
manuscript: all authors. Approved the final version of the manuscript
on behalf of all authors: Coric. Administrative/technical/material
support: Boltes.
Acknowledgments
The authors would like to thank H. Davis Adkisson, Ph.D.,
Nicole Rittenhouse, M.A., Raquel Scharkopf, and Ben Rogers for
their assistance with manuscript preparation.
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Manuscript submitted May 18, 2012.
Accepted October 3, 2012.
Portions of this work were presented as a podium presentation
at the AANS/CNS Joint Section on Spine and Peripheral Nerves,
Orlando, Florida, March 9, 2012.
Please include this information when citing this paper: published
online November 9, 2012; DOI: 10.3171/2012.10.SPINE12512.
Address correspondence to: Domagoj Coric, M.D., Carolina Neurosurgery and Spine Associates, 225 Baldwin Avenue, Charlotte,
North Carolina 28207. email: [email protected].
11