process study 24-month results

Process Study24-Month ResultsOctober 1, 2008(abridged)

2 | MDT Confidential

Study Design for Primary Endpoint(≥ 50% Reduction in Leg Pain (VAS) at 6 Months)


PROCESS Study Summary of ITT Results Until 6 Months (Kumar K et al. Pain 2007)

• Patients in the SCS and CMM groups were:– Well matched– Representative of patients with FBSS, suffering from neuropathic pain

predominantly in the legs

• Significantly better outcomes were observed in the SCS group in terms of: – Pain relief (leg and back VAS) – the primary outcome

• 48% patients reaching ≥ 50% leg pain relief vs. 9% in CMM group

• 64% patients reaching ≥ 30% leg pain relief vs. 18% in CMM group

– Disability (Oswestry Disability Index)– Quality of life (SF-36 and EQ-5D)– Patient satisfaction– Occurrence rate of SCS-related events comparable to literature


24-month AnalysisSCS-continue Group

• The 24 month analysis focuses on the SCS+CMM-continue group– i.e. patients randomised to SCS who remained on SCS until 24 months

• The following analyses have been limited to the primary outcome only (vs. CMM):

– Revised ITT (where all patients requesting crossover are considered as having < 50% pain relief at 24 months)

– Per treatment analyses (based on the treatment the patient is receiving at the 24 months visit)


Rationale For Focusing on the SCS Continue Group

High and uneven crossover after 6 months – 4 / 46 (9%) SCS+CMM patients with a 24m visit had crossed to CMM– 30 / 41 (73%) CMM patients with a 24m visit had crossed to SCS+CMM

other analyses no longer relevant

Analyses Reason for non relevance

Per ITT the treatments received were very different from those to which the group was randomized (especially for the CMM group)

Per treatment This analysis would mix patients with 24-months of treatment (i.e. patients who continued on their treatment) with patients with 12–18 months of treatment (i.e. those who switched post 6 months)

SCS vs. CMM continue groups

The small number of CMM-continue patients (n=11) implies that:The CMM-continue group would no longer be representative of the initial group

Even if statistical tests were performed to compare SCS vs. CMM or changes from baseline, it is very unlikely that these would show significance


Patient Flow Through 24 Months


Leg Pain Relief in SCS+CMM-continue Group Over 24 Months

Significant Reduction in Leg Pain VAS Over 24 Months


Primary Outcome: ≥ 50% Leg Pain Relief at 24 MonthsContinued Greater Effect with SCS in the Per Treatment/ITT Analyses Over 24 Months


Leg Pain Relief in SCS+CMM-continue Group at 24 Months ≥ 30% Leg Pain Relief Maintained in the Majority of Patients Over 24 Months


QoL in SCS+CMM-continue Group at 24 MonthsSignificant Improvement in 7/8 Domains of QoL (SF-36) Over 24 Months


Quality of Life in SCS+CMM-continue Group Over 24 MonthsSignificant Increase in QoL (EQ-5D) Over 24 Months


Function in SCS+CMM-continue Group Over 24 Months Significant Improvement in Function (Oswestry Disability Index) Over 24 Months


Satisfaction in SCS+CMM-continue Group Over 24 MonthsHigh Patient Satisfaction Maintained Over 24 Months

“Are you satisfied with the pain relief provided by your treatment?”

“Based on your experience so far, would you have agreed to this treatment?”


SCS-related Complications in SCS-continue Patients: 24 Months19 (45%) Patients Had Total 34 Complications, 13 (31%) Patients Required Surgery

IPG: implantable pulse generator; * 1) Case of suboptimal connection of extension to IPG, leading to intermittent stimulation; 2) Lead implanted anteriorly, leading to patient receiving shocks; 3) lead cut during implant

SCS-related adverse event at 24 monthsNumber of

events

Patients with ≥1 eventPatients requiring

surgery

Number (%) Number (%)

Hardware related 14 10 (24) 8 (19)

Lead migration 9 6 (14) 6 (14)

Lead/extension fracture/ torqued contacts 4 3 (7) 1 (2)

IPG migration 1 1 (2) 1 (2)

Loss of therapeutic effect, lost or unpleasant paresthesia 5 5 (12) 2 (5)

Technique* 3 2 (5) 2 (5)

Biological 12 9 (21) 3 (7)

Infection / wound breakdown 4 4 (10) 2 (5)

Pain at IPG incision site / Pocket inflammation 5 5 (12) 1 (2)

IPG pocket fluid collection 3 2 (5) 0 (0)


PROCESS Study Summary of Results at 24 Months

• In ITT and per treatment analyses, significantly more SCS patients achieved the primary outcome of ≥ 50% leg pain relief.

• Significant difference from baseline achieved in the SCS-continue group in main outcomes:

– Leg pain relief (p < 0.0001)– Quality of life (SF-36 and EQ-5D, p ≤ 0.01)– Disability (ODI, p = 0.0002)

• No significant change in drug and non drug treatments• Complications in line with the literature

– 45% of patients had ≥ 1 complications, 31% of patients required surgery

• High patient satisfaction, increasing number of patients return to work

Sustained effect of SCS over 24 months


Thank You to the Participating Centers!

UC201002470 EN

process study 24-month results

Documents