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Purpose of the Meeting. To determine if, under the 505(b)(2) pathway, an efficacy trial in the adjuvant treatment of node-positive breast cancer is required to approve Abraxane in this setting. . 505(b)(2) Regulatory Pathway. 505(b)(1):
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1. Abraxane®for the adjuvant treatment of node-positive breast cancer Oncologic Drugs Advisory Committee Meeting
September 7, 2006
2. Purpose of the Meeting To determine if, under the 505(b)(2) pathway, an efficacy trial in the adjuvant treatment of node-positive breast cancer is required to approve Abraxane in this setting
3. 505(b)(2) Regulatory Pathway 505(b)(1): ‘Typical’ way most new drugs are approved; all investigations from sponsor
505(b)(2): Used for new formulations of existing drugs; applicant may rely on investigations to which it does not own or have the right of reference (e.g. information in the published literature or in approved NDAs for the RLD)
505(j): For generic drugs that are the same as the established drug (the ‘Reference Listed Drug’ [RLD])
4. FDA Position Regarding 505(b)(2) “FDA’s longstanding interpretation of section 505(b)(2) ……… the Agency’s approach is to use the 505(b)(2) drug approval pathway to avoid requiring drug sponsors to conduct and submit studies that are not scientifically necessary.”
“The conduct and review of duplicative studies would …. slow the process for drug approval with no corresponding benefit to the public health.”
5. 505(b)(2) Avoids Significant Delays inDrug Approval ‘FDA has approved more than 80 section 505(b)(2) applications for drugs for indications ranging from cancer pain to attention deficit disorder. Many of these drugs would never have reached the market, or would have been significantly delayed, without the 505(b)(2) pathway.’
6. Unique Set of Circumstances for Abraxane Active ingredient, paclitaxel, is identical
Paclitaxel already approved as Adjuvant Rx(Taxol 175 mg/m2)
Abraxane delivers a higher dose of paclitaxel(260 mg/m2)
Superior anti-tumor activity demonstrated in metastatic breast cancer
Tolerability of higher Abraxane dose comparable to lower Taxol dose
Abraxane was approved in metastatic breast cancer under 505(b)(2)
FDA approach is to use 505(b)(2) “to avoid…. studies that are not scientifically necessary”
7. Position of Abraxis BioScience
Abraxis believes that an efficacy trial in the adjuvant treatment of breast cancer is ‘not scientifically necessary’ and ‘would significantly delay’ the approval of a Cremophor-free paclitaxel alternative
Abraxis is committed to conduct a comparative safety trial of Abraxane vs Taxol for women with node-positive breast cancer
8. Reasons that an Efficacy Adjuvant Trial Should not be Required for Approval of Abraxane
9. Reasons that an Efficacy Adjuvant Trial Should not be Required for Approval of Abraxane
William J. Gradishar, MD
10. Development of Paclitaxel Formulations:Historical Background Paclitaxel, one of the most active cytotoxic agents
Cremophor® required at high concentrations (Taxol® and generic equivalents)
In the 1990’s, Abraxis developed a paclitaxel formulation that replaced Cremophor with Albumin (Abraxane®)
Preclinical studies subsequently demonstrated that Abraxane significantly improved the therapeutic index of paclitaxel with
Less toxicity due to removal of Cremophor
Higher paclitaxel dose
Higher intra-tumoral paclitaxel concentration
Higher efficacy in multiple tumor types
11. 2001: FDA agreed that Abraxane could receive approval in MBC (same indication as Taxol) provided two issues were satisfied:
That replacement of Cremophor with albumin did not result in a decrease in efficacy of paclitaxel
That the higher dose 260 mg/m2 of Abraxane could be administered with comparable tolerability to Taxol at175 mg/m2
2004: Randomized Phase 3 Trial proved superior anti-tumor activity of Abraxane with comparable tolerability at higherdose than Taxol
2005: FDA granted approval for metastatic breast cancerunder the 505(b)(2) regulatory pathway for new formulationsof existing drugs Basis of FDA Approval of Abraxane for Metastatic Breast Cancer
12. Reasons that an Efficacy Adjuvant Trial Should not be Required for Approval of Abraxane
13. Abraxane is Albumin-bound Cremophor-free Paclitaxel
14. The Active Ingredient in Abraxane and Taxol is Identical
15. Abraxane was Developed to Eliminate Cremophor-induced Hypersensitivity Reactions Hyperglycemia
Glucose intolerance in diabetics
Mood changes
Insomnia
16. Abraxane was Developed to Eliminate Cremophor-induced Hypersensitivity Reactions
17. Removal of Cremophor Results in Different PK for Taxol and Abraxane PK linearity
Alterations in distribution phase
18. Cremophor Entraps Paclitaxel in Micelles in the Plasma Compartment
19. Paclitaxel PK for Abraxane are Linear
21. Reasons that an Efficacy Adjuvant Trial Should not be Required for Approval of Abraxane
22. Reasons that an Efficacy Adjuvant Trial Should not be Required for Approval of Abraxane
23. Abraxane can Deliver Higher Paclitaxel Dosewith Comparable Tolerability to Taxol
24. Abraxane and Taxol have Comparable Overall Toxicity Profiles
25. Tolerable GI Toxicities for Abraxane and Taxol
26. Taxane and Cremophor Related Toxicities
27. Improvement from Grade 3 Sensory Neuropathy and Resumption of Treatment with Abraxane (n = 24)
28. Reasons that an Efficacy Adjuvant Trial Should not be Required for Approval of Abraxane
29. Results of a Pilot Adjuvant Trial of Dose Dense Abraxane CA030: U.S. Oncology (P.I. Nicholas Robert)
Dose Dense AC x 4 ? Abraxane x 4 (all cycles q2w)
Abraxane dose 260 mg/m2
30 received AC; 29 received Abraxane
27/29 (93%) received all 4 Abraxane cycles
Comparable to Taxol q 3 weeks
Mean cumulative dose 962 mg/m2
Well tolerated without unexpected toxicity
Peripheral neuropathy prospectively monitored and followed to resolution
28/29 (97%) patients asymptomatic 8 months following treatment
30. 28/29 (97%) Patients were Asymptomatic* fromPeripheral Neuropathy within 8 Months Following Dose Dense Abraxane at 260 mg/m2
31. Ongoing Adjuvant Safety Trials
32. Design of Proposed Comparative Safety Study using the Approved Dosing Schedules of Abraxane and Taxol
33. How Similar or Dissimilar are Taxol and Abraxane? The active ingredient in both formulations is paclitaxel
Administration Differences
Cremophor-related HSRs are eliminated with Abraxane
No steroid premedication required with Abraxane
Standard IV tubing with shorter infusion time
Differences in PK due to paclitaxel sequestration by Cremophor
The removal of Cremophor permits delivery of a 50% higher dose of paclitaxel than that of Taxol
Despite higher dose the tolerability of Abraxane is comparable to that of Taxol
Abraxane demonstrated higher anti-tumor activity than Taxol in metastatic breast cancer
34. Reasons that an Efficacy Adjuvant Trial Should not be Required for Approval of Abraxane