Wyeth Response to July 2008 Pharmaceutical Benefits Advisory Committee (PBAC) Decision on Enbrel (etanercept) for Treatment of Chronic Plaque Psoriasis

Background
Enbrel (etanercept) was recommended for reimbursement for the treatment of chronic plaque psoriasis at the March 2006 PBAC meeting, with listing implemented in August 2006.

Wyeth did not request the current inflexible intermittent drug regimen. The PBAC recommended listing on a cost-minimisation basis, where Enbrel treatment (50 mg per week) has similar effectiveness compared to Raptiva (efalizumab) treatment (1mg/kg per week), and 24 weeks of Enbrel treatment is similar in cost compared to 48 weeks of Raptiva treatment. An Enbrel cyclical (intermittent) regimen was recommended by PBAC, with a minimum 12-week treatment break between 12-week courses of etanercept.

During the review process, Wyeth requested Enbrel to be used in a flexible intermittent manner. This request was based on clinical data (Gordon et al, 2006),¹ which showed on average 50% of patients need to re-start treatment within 12 weeks. For example, some patients would re-start after 3 weeks, some after 4 weeks, some after 20 weeks, etc, based on clinical need. However, the PBAC did not accept Wyeth’s proposed treatment re-start criteria; thus, the current inflexible intermittent regimen was implemented with mandated minimum 12-week treatment breaks.
 
Wyeth did not agree with the inflexible intermittent nature of the original recommendation and re-submitted to PBAC in November 2006 and again in March 2008. Both submissions provided additional data to give greater certainty about the flexible intermittent treatment regimen. Both submissions were rejected.

July 2008 PBAC Meeting
The recent March 2008 submission was reviewed by the PBAC in July 2008. This submission included data from new clinical trial (Ortonne et al, 2008)² that showed that flexible intermittent treatment is efficacious over at least one year. This trial showed that patients took treatment breaks of 10.4 weeks on average (range 1.3 to 37.1 weeks) when re-treatment was based on clinical need, as assessed by the clinician. The submission also proposed that a certain proportion of patients would relapse quickly and thus would not take any breaks in therapy at all.

However, one of the key reasons for the PBAC rejection was uncertainty about whether this clinical trial represented the manner in which Australian clinicians would implement this regimen in a real-life setting.

What Next
Wyeth is committed to ongoing negotiations with the government to implement a quality use of medicines approach by changing the currently mandated inflexible intermittent drug regimen to provide better treatment options for patients.

For further information please contact Dr. Michael Nobes on (02) 8850 8266.

References

1. Gordon KB, Gottlieb AB, Leonardi CL, Elewski BE, Wang A, Jahreis A, Zitnik R, Group EPS. Clinical response in psoriasis patients discontinued from and then reinitiated on etanercept therapy. Journal of Dermatological Treatment 2006;17:9-17.
2. Ortonne, Griffiths, Strohal, Estojak, Robertson, Molta. Efficacy and Safety of Continuous Versus Intermittent Etanercept in Patients with Moderate-to-Severe Psoriasis Over 54 Weeks: Improved Efficacy Demonstrated in the CRYSTEL Study. 2008. 5th European Academy for Dermatology and Venereology  Spring Symposium, 22nd - 25th May 2008 Istanbul, Turkey.