1 fda oncology drug approval endpoints, effectiveness, and approval gerald h. sokol md, ms, fcp* and...

92
1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products Office of Oncology Drug Products CDER, FDA Not an official FDA policy Asst. Prof Medicine and Clinical Pharmacology Uniformed Services University or the Health Sciences

Upload: brendan-fisher

Post on 15-Jan-2016

250 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

1

FDA Oncology Drug Approval

Endpoints, Effectiveness, and ApprovalGerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP

Division of Drug Oncology ProductsOffice of Oncology Drug Products

CDER, FDANot an official FDA policy

Asst. Prof Medicine and Clinical PharmacologyUniformed Services University or the Health Sciences

Page 2: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

2

The medical reviewer in his natural habitat

Page 3: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

3

Page 4: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

4

The “White Oak” Consolidation

Page 5: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

5

Page 6: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

6

FDA - Oncology Drugs

• Not – Drug imports from Canada

• Not – Vioxx, Celebrex, Plan B

• Not – dietary supplements -Foods

• No stock market tips

Page 7: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

7

FDA Oncology Drug Approval

• FDA – U.S. Food and Drug Administration– In the Dept of HHS – Executive Branch

• Created by Congress because of prior unsafe drugs being marketed

• FDA charged by Congress to evaluate all prescription drugs seeking marketing in the U.S.

• Federal Laws, Regs govern these activities

Page 8: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

8

Communication is the Key

Page 9: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

9

Overview for oncology drug approval

• Evidence for efficacy and safety• Good Evidence = Approval • Endpoints for trial design• Endpoints for FDA approval• Trial design issues for efficacy• Trial results analysis• “Targeted” therapy approval and problems

Interplay of disease state, existing Rx options, endpoint options, strength of evidence

Page 10: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

10

Regulatory Perspective on Drug Development and Approval

Pre IND

1 2 3 4

Non – clinical studies

~~~~FDA Consultation~~~~~~~~~~~~~~~~~~~

IND Filing NDA Filing

Comprehensive multidisciplinary review often with

Advisory Committee discussion

Monitor safety, review new protocols, annual

reports, approve exceptions

Safety and Phase 4 monitoring

Regular Accelerated

NDA Filing

Approval options

Page 11: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

11

Drug Development Focal Points -FDA Meetings

Phase Format Intent (FDA concerns)

Pre-IND / IND

T-con, FTF, none

Ph 1 design – FDA safety -population and dosing

EOP1 Tcon, FTF Ph 2 design – FDA safety - population and dosing

EOP2 FTF Ph 3 design – FDA safety, study design & analysis

Pre-NDA FTF

(face to face)

Results; format & content of reports; time frame of submission; priority?

Page 12: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

12

FDA - Oncology Drugs

• Office of Oncology Drug Products – OODP• Three divisions

DDOP- Chemotherapy drugs for Cancer

DBOP- Biologic oncology therapies BLAs

DMIHP- Medical Imaging and hematology

Page 13: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

13

Requirements for Drug Approval

U.S. Statutes –Congress

Labeling 1906 Pure Food & Drug Act

Safety 1938 Food, Drug, and Cosmetic Act

Efficacy 1962 FDC Amendments Harris-Kefauver

FDAMA Amdnts. 1997

Code of Federal Regulations (CFRs)

Regulations from FDA provide interpretation of the laws

Page 14: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

14

Drug Approval Tracks

• FDA Modernization Act 1997 (FDAMA): CFR 312 subpart E regulations

• To expedite development for life-threatening illnesses

– Fast track • process for meeting FDA -unmet med need

– Priority review • Determined by FDA after NDA submitted• 6 month NDA review time frame for products

addressing unmet medical need

Page 15: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

15

Drug Approval Tracks (2)

• Accelerated approval “CFR 314 subpart H” – 1992

• Special Protocol Assessment – agreement between FDA and sponsor on

clinical protocols for phase 3 studies forming primary basis for demonstrating efficacy for NDA; 45 day clock

Page 16: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

16

FDA Oncology Drug Approval

• How do you achieve approval ?

• Provide substantial evidence of

Efficacy and Safety

• What is substantial evidence for Effectiveness– “A & WC investigations” CFR 314.126

• 2 or more studies

– required by 1962 amend. to FFDCA Source = Controlled clinical trials

Page 17: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

17

Basis for New Drug Approval

• Demonstration of efficacy with acceptable safety in adequate and well-controlled studies CFR 314 - NDA Regulations

• Ability to generate product labeling that– Defines an appropriate patient population for

treatment with the drug– Provides adequate information to enable safe

and effective use – prescribing of the drug

• Analogous rules for Biologics - BLA

Page 18: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

18

FDA Oncology Drug Approval

• Clinical trials:– When we do not know which therapy is better– Patients are fully informed of the uncertainty

about which therapy is better and give consent– We can compare one treatment with another in

a controlled way– Today’s “standard” therapy was last year’s

investigational treatment

Page 19: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

19

FDA Oncology Drug Approval

• Controlled clinical trials:– Can be verified, repeated if necessary– Can allow us to be convinced a new therapy

is effective – or it is not.– Allow us to compare how well tolerated -

(how safe) a new therapy is versus a standard

• Efficacy with Safety => Approval

Page 20: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

20

Some trial considerations

• Usual situation for many FDA drug approvals– Multiple studies– Studies are large 1,000 – 5,000 patients– Placebo control group– Double Blinded or a blinded independent assessment– Highly significant p values (0.001)

• Oncology drug data submitted for approval– One study, 100 – 800 patients– No blinding, no placebo control– Heterogeneous patient group– Statistical evidence ~ 0.03 – 0.05*Concern – how confident can we be that results are real

Page 21: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

21

The FDA mission is not a new idea!

"The aim ... is not simply to accept the statements of others, but to investigate the causes that are at work in nature."

Albertus Magnus, de Mineralibuscirca 1250

Page 22: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

22

FDA Oncology Drug Approval

• Suppose YOU are the FDA –

• What benefits should a new drug have to allow its marketing approval in the U.S.?

• How “safe” should the drug be?

Page 23: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

23

FDA Oncology Drug Approval

• What benefits should a new drug have for marketing approval in the U.S.?

• LIVE LONGER ---------------------Effective

• LIVE BETTER – QUALITY ------Effective

Page 24: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

24

FDA Oncology Drug Approval

• What benefits should a new drug have for marketing approval in the U.S.?

• LIVE LONGER ---------------------Effective• LIVE BETTER – QUALITY ------Effective• Improved safety - with efficacy• Benefits outweigh Risks (312.84)

• B / R assessment - in disease context

• COST ? Less expensive? / Reimbursement ?– Not purview of FDA

Page 25: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

25

FDA Oncology Drug Approval

• Judgment of Benefits versus Risks

• But - NEVER Have ALL the Data

• Some benefits or adverse effects occur:– Rarely– After long time interval

• How long to study and wait before Approval

• Too slow or too fast to approve?

Page 26: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

26

What Drugs Are Safe ?

Page 27: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

27

What Drugs Are Safe ?

None of them

Page 28: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

28

What Drugs Might Help Someone?

Page 29: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

29

What Drugs Might Help Someone?

All of them

Page 30: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

30

Can we tell in advance who might be helped and

who might be hurt by a drug?

Page 31: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

31

Can we tell in advance who might be helped and

who might be hurt by a drug?

NO

But we hope to be able to soon

Page 32: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

32

Two Types of Drug Approval: Regular or Accelerated

Endpoints Supporting Regular Approval Regular Approval Demonstrate Clinical Benefit– Longer life – Better life (relief of tumor-related Sx) - PRO

• Requires a valid measure of how a patient feels or functions

– Favorable effect on established surrogate

Page 33: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

33

Accelerated Approval (AA)

Only applies in the setting of a new drug for a serious or life-threatening illness:

• Improvement over available therapy

• Study may use a surrogate endpoint, reasonably likely to predict clinical benefit

• Requires confirmation of benefit

Fed Register 1992

Page 34: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

34

Oncology Trial Endpoints (1)

CLINICAL BENEFIT ENDPOINTS• LIVE LONGER – Measure Survival- OS

Efficacy, reassures for safety, unbiased endpt but – subsequent therapy, long time required

• LIVE BETTER – Measure QOL – PROImportant: control group + blinding needed (bias)

hard to measure, scale problems, missing data

Drug Tox. symptoms versus tumor symptoms

=> COMPARISONS ARE NECESSARY

Note – These endpoints do not measure the tumor

Page 35: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

35

Tumor measurement endpoints

Randomize Response Progression Death

or recurrence

I__________I__________I__________ITime to Response Response Duration

Metastatic - Time to Progression (TTP) ---- PFS

Adjuvant - Time to Recurrence ---- DFS

Overall Survival

Page 36: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

36

Oncology Endpoints (2)

• DISEASE-FREE SURVIVAL (DFS)

– Composite of survival and NED – Recurrence is associated with symptoms,

new therapies, cognitive effects

– Adjuvant treatment setting

• Breast cancer

• Colorectal cancer–3 year DFS (p ≤ 0.03) => 5 year OS

• New areas likely – lung, prostate, brain, etc

Page 37: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

37

Endpoints - Regular Approval (3)

• Survival

• QOL – PRO• Safety improved- with efficacy

• DFS – adjuvant and leukemia settings

• Improvements convey/are clinical benefits

• Improvements show effectiveness

Demonstrate these endpoints

= (Full) Regular Approval (RA)

Page 38: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

38

Tumor assessment endpoints (5)

• Response - Response rate (RR) = Drug activity (not the same as efficacy)

anatomic imaging – measure tumor - RECIST criteriaComplete responses (CR) – stronger evidence

• Time to progression (TTP) Progression – anatomic imaging - RECIST based Includes stable disease (natural history)

• Progression-free survival (PFS) – Composite of progression (TTP) and Death– Includes stable disease [ODAC (preliminary) – several months’ difference]

Page 39: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

39

Tumor assessment endpoints (6)

• Biomarkers – many different roles, utilities– Screening; diagnosis; predictive; prognostic

• Genomic or proteomic (protein): uses– Eligibility – enrich the study population– Stratification– As study endpoint for efficacy or toxicity - NO

Page 40: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

40

Tumor assessment endpoints (7)

• Biomarkers: not reliable to date as predictive of response outcomes– CEA failure to correlate for colon– CA-125 ovarian ?– PSA response failed to correlate with survival

Tax 327 approval study example

Page 41: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

41

Random

ize

Mitoxantrone 12 mg/m2 Q3 weeksPrednisone 10 mg q dayup to 10 cycles

Docetaxel 75 mg/m2 Q3 weeksPrednisone 10 mg q dayup to 10 cycles

Docetaxel 30 mg/m2 Q 1 wkPrednisone 10 mg q day5 on; 1 off x 6 cycles

N=1006

Biomarker “surrogacy” from TAX 327 study

M Eisenberger, et al. Proc ASCO, 2004. Abs 4.

Page 42: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

42M Eisenberger, et al. Proc ASCO, 2004. Abs 4; D Petrylak, et al. Proc ASCO, 2004. abs 3.

Docetaxel 3-weekly

Docetaxel weekly

M+P

PSA response

45 48* 32

Pain response

35% 31% 22%

Meas. Dis response

12% 8% 7%

Med OSmonths

18.9 17.4 16.5

Logrank p

HR (95% C.I.)

versus M+P

0.009

HR=0.76 (0.62, 0.94)

0.36 *

HR=0.91 (0.75, 1.11)

Docetaxel HRPC TAX 327 Trial- PSA endpoint

Page 43: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

43

Tumor assessment endpoints and approval (7)

• RR / TTP / PFSHope – get results faster from studies

Often used in phase 2 studies with single arm

Hard to judge in single arm - no comparator

• Are these “surrogate” endpoints ?Problem - inconsistent relation to clinical benefit in

phase 3 trials

• Valid surrogates: Blood pressure / Cholesterol

– Strong and consistent relation with outcomes

Page 44: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

44

Approval and tumor assessment endpoints (8)

Regular Approval – RA– If Clinical Benefit shown (live longer, better, safer) - or -– Benefit on Established surrogate - (DFS, Heme CR)

Accelerated Approval - AA For Serious or Life Threatening illnesses• Show meaningful therapeutic benefit over

existing therapy or improved patient response over available therapy

• May be based on a surrogate endpoint which is reasonably likely to predict clinical benefit - or

• a clinical endpoint other than survival or irreversible morbidity

Page 45: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

45

Tumor assessment endpoints: TTP (9)

• Advantages:– Smaller sample size, shorter follow-up– Results sooner than a survival endpoint – Not affected by subsequent Rx– Determined by the entire treated group,

not just responders (= response duration)– May correlate with delay of new or more severe

symptoms or complications of malignancy

Page 46: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

46

Tumor assessment Endpoints: TTP (10)

• Limitations– Most oncology trials unblinded =>

assessments may be subject to bias• Physicians may choose when to assess a particular

symptom or a tumor marker• Missing measurements of target / non-target lesions• Asymmetry of assessment timing

• Need precise prospective definition of TTP• Consistent supportive evidence also

– RR, PRO

Page 47: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

47

TTP in Breast Cancer (11)

• ODAC Meeting 6-99 examined TTP in MBC• MBC using First-line cytotoxic treatment

• TTP not shown to correlate with OS or QOL– May be a problem of TTP magnitude, later Rx

• ODAC advised: TTP not be used alone for RA– Epirubicin: not approved for MBC – study used

primary endpoint TTP

• Potential use as surrogate endpoint for accelerated approval in RCTs with same study continued to survival endpoint

Page 48: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

48

What about Response - CR or PR (12)

• CR = complete response PR = partial response– assessment must be prospectively defined: when, how– published criteria available to define response

• RECIST, NCI-WG, IBMT, etc

– In phase 2, response => ACTIVITY, not benefit– Is it associated with symptom benefit?– Durability of response is important

• MBC with hormone Rx: RR + TTP may => RA• Durable CRs in Hematologic malignancies

– fewer infections, visits, transfusions –

– may => RA

Page 49: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

49

What about Response - CR or PR (13)

• Examples of CR based regular approvals:– Cladribine for hairy cell leukemia (CRs > 8mo)

– Pentostatin for hairy cell leukemia CRs > 24 mo

– Ifosfamide in combination for 3rd-line therapy of germ cell testicular tumors (CRs > 2 years)

– IL-2 for renal cell carcinoma / melanoma – cures ?

– AsO3 and ATRA for APL – RA: small, single arm

Page 50: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

50

Approval and tumor assessment endpoints (14)

• AA uses tumor assessment endpoints Magnitude and consistency of effect importantRR + TTP may achieve AA TTP alone unlikely to be sufficientRR + TTP with hormone Rx – breast cancer may => RA CRs with Duration – Hematologic cancers may => RA

Endpoints and FDA Oncology Drug ApprovalsJohnson, Williams, PazdurJournal of Clinical Oncology 2003; 21:1404-1411

• Disease - Endpoint – Drug - Approval

Page 51: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

51

Effectiveness: Oncology Trial Design (1)

How to show effectiveness – 1. Choose appropriate endpoint (with FDA)

• Disease, therapy, and regulatory context

2. Choose appropriate study design (with FDA)

– Phase 2 or phase 3 – many phase 2 results not confirmed in phase 3!

– Usually phase 3 with comparator arm of:• Standard of care treatment or Placebo

• Prospective, randomized, blinded * comparison– Blinding or masking: allocation, investigator, patient, sponsor

Page 52: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

52

Effectiveness: Oncology Trial Design (2)

2. Appropriate study design: How to compare?• Type of comparison – Superiority vs. Non-inferiority

– Superiority: • versus placebo or add-on design • “head to head” with an active control Rx (risky)

– Non-inferiority – problems IN ONCOLOGY

• Estimating effect of control treatment• Constancy assumption - historical control• Retention margin• Large sample sizes required

Page 53: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

53

Effectiveness: Oncology Trial Design (3)

3. Appropriate Analysis Plan– Pre-specified - why?

• Control error rate (chance of false positive conclusion)

• Not post-hoc, data-driven– Estimate the difference to be detected

• What can your new drug do?

– Size the study – what power do you want to have to demonstrate the primary endpoint

– ITT population for comparison of arms – Why ?

Page 54: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

54

Effectiveness: Oncology Trial Design (4)

– ITT population for comparison of arms – Reduces Bias

• Cannot define the analysis population AFTER data examined

– ITT to see differences between arms

Page 55: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

55

Effectiveness: Oncology Trial Design (5)

4. Statistical meaning– Null hypothesis = assume no difference between groups– Stat test – How likely is this difference a result of chance?– If unlikely due to chance, maybe due to treatment?– FDA concern - Error of a false positive conclusion (1/20)

• ? Acceptable error rate – pre-specified = Alpha • two-sided 0.05 - generates our P < 0.05

– If there’s no difference found? ≡ Equivalence?

• No! –Only means you cannot reject null hypothesis– Bayesian perspectives

4. Clinical meaning beyond statistical meaning

Page 56: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

56

Oncology Approval Example - Prostate

• 2004 Docetaxel (Taxotere) approval for HRPC

• 2003 - Approved drugs for treatment of HRPC

– Estramustine 1981

– Mitoxantrone 1996 *

– Zoledronic acid 2003 *

* approvals based on QOL-PRO not on survival

Page 57: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

57

Random

ize

Mitoxantrone 12 mg/m2 Q3 weeksPrednisone 10 mg q dayup to 10 cycles

Docetaxel 75 mg/m2 Q3 weeksPrednisone 10 mg q dayup to 10 cycles

Docetaxel 30 mg/m2 Q 1 wkPrednisone 10 mg q day5 on; 1 off x 6 cycles

N=1006

TAX 327

SWOG 9916

Random

ize

Mitoxantrone 12 mg/m2 Q 3 weeksPrednisone 5 mg bid

Docetaxel 60 mg/m2 d 2 Q 3 weeksEstramustine 280 mg d1-5*Dexamethasone 20 mg, tid d 1 & 2

N=770

*Warfarin and aspirin

M Eisenberger, et al. Proc ASCO, 2004. Abs 4; D Petrylak, et al. Proc ASCO, 2004. abs 3.

Page 58: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

58

Docetaxel HRPC TrialsStatistical Designs

TAX 327• Power: 90% to detect a

25% reduction in hazard of death (HR=0.75)

• Accrual - 1006 patients

• Two studies available -

HRPC – hormone-refractory prostate cancer

SWOG 9916• Power: 80% to detect a

33% reduction in hazard of death (HR=0.67)

• Accrual - 770 patients

not just one

Page 59: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

59

Mediansurvival Hazard

(mos) ratio P-value

D Combined: 18.2 0.83 0.03

D 3 wkly: 18.9 0.76 0.009D wkly: 17.3 0.91 0.3Mitoxantrone 16.4 – –

Months

Pro

bab

ilit

y o

f S

urv

ivin

g

0 6 12 18 24 30

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Docetaxel 3 wkly

Docetaxel wkly

Mitoxantrone

M Eisenberger, et al. Proc ASCO, 2004. Abs 4.

Survival (overall survival) -TAX 327

---------------------------------------------------

Page 60: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

60

“Statistically Significant” Results

• Response rates – proportions - Chi square test • Survival curves – KM - time to event (OS, PFS)

– Median survival – midpoint on KM curves• Why not 75% or 25% ?• Why not 1 year or 2 year survival (% alive at __)

– P value - logrank test comparing the survival distributions (curves)

– Hazard ratio – Cox model assumptions– Confidence intervals (not overlap 1)

• Clinically significant ?

Page 61: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

61

Statistical / Clinical Significance ?

• Best case – have both

• Can you have stat sig. but not clinical - yes– Approval likely ? No

• Can you have clinical sig. but not stat - yes– Approval likely ? It depends

• Phase 2 results• Statistical design may become inappropriate• Safety advantage, Other• Clinical benefit is the goal!

Page 62: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

62

FDA Oncology Drug Approval

• Regulatory consequences of

Demonstrating Efficacy

• Regular Approval if: clinical benefit endpoint – OS, QOL, DFS, and occasional other

• Accelerated Approval if:• Benefit over existing therapy – if any; and• If a surrogate, then “reasonably likely” to predict, and• Must verify clinical benefit later

• If efficacy uncertain – ODAC likely

Page 63: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

63

Evidence for Accelerated Approval

• Substantial evidence from well controlled clinical trials regarding a surrogate endpoint

• NOT: Borderline evidence regarding a clinical benefit endpoint

Page 64: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

64

FDA Review Times

• Assuming a complete application and no substantive amendments submitted during the review

• Priority review completion: – 6 months– May fulfill an unmet medical need– Substantial improvement

• Standard review completion: – 10 months

Page 65: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

65

Ages of Oncology Drug Approval

• Historical Era– Response rates - approval

• Current Era– Statistical refinements– Clinical Benefit and surrogate endpoints

• Molecular Era

Page 66: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

66

Molecular Era (1)

• Characterizing both Disease and Patient– Individual Patient characteristics

• Individualized dosing – PG profile of each person including CYPs, receptors, transporters

– Individual Tumor characteristics• Receptors, transporters• Targets

– Enriched populations with target– Study designs to assess role of the target

• More selective drug effects

• Individualized therapy

Page 67: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

67

Molecular Era (2)

• Phenotype to Genotype: will redefine the disease, the patient, and the indication

• Phenotype to Genotype - examples– MCL: Cyclin D1 over-expressed or t(11,14) CD20

B cell lymphoma of nodes, spleen and marrow– NSCLC: “Taressa” indicated for EGFR Exon 20 activating

mutation, Bcl-2 overexpressed, cancer in lung or kidney except for CYP2D6 slow metabolizers

• Hope – we no longer have to tell someone –

there’s a chance this therapy may help you – but we can’t predict …

Page 68: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

68

Oncology targeted therapies 2006 (3)

Monoclonal Antibodies: approval target label ?Rituxan (Rituximab) – lymphoma 1997 CD20 yesHerceptin (Trastuzumab) - breast 1998 p185neu yes*Mylotarg (Gemtuzumab) - AML 2000 CD33 yes*Campath (Alemtuzumab) – CLL 2001 CD52 no *Erbitux (Cetuximab) – colon 2004 EGFR yesAvastin (Bevacizumab) – colon 2004 VEGF no

Label ? - Is a test for the target included in the label indication?(May not be exactly the same test as the target assay)

(Radio-immunoconjugates- Zevalin (2002) and Bexxar (2003): anti-CD20)

*AA products - Comparative, randomized trials demonstrating increased survival or clinical benefits such as improvement in disease-related symptoms have not yet been conducted.

Page 69: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

69

Oncology targeted therapies 2006 (4)

• Small molecule inhibitors approval target label ?

– Nolvadex (Tamoxifen)-Breast 1977 ER yes

– Vesanoid (ATRA) ----- APL 1995 RARα yes

– Gleevec (Imatinib) ---- CML 2001 bcr/abl yes

– *Gleevec (Imatinib) -- GIST 2002 c-kit yes

– *Iressa (Gefitinib) ----- Lung 2003 EGFR? no

– Tarceva (Erlotinib) ---- Lung 2004 EGFR? no

Label ? – Is a test for the target included in the label indication?

*AA -comparative, randomized trials demonstrating increased survival or clinical benefits such as improvement in disease-related symptoms have not yet been conducted – AA

Page 70: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

70

Allsubjects

Responders

Drug treatment

Non-responders

Usual target study plan - Retrospective

Target- subjects

Target+ subjects

Target- subjects

Target+ subjects

Problem: retrospective and subgroup analysis- Imbalances

Page 71: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

71

Allsubjects

Target POS subjects

All Target-tested

Target NEG subjects

Prospective, Stratified: assess effect in Target POS and NEG patients

Control

Drug

Control

Drug

For target assay utility where predictive value unknown or well below 100% – focus is on the target

®

®

® = randomization

Page 72: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

72

Prospective, Stratified Evaluation of Biomarker

All subjects All PG tested

Test is -

Test is +Placebo

Drug

Placebo

Drug

All subjects

All PG tested but not available at randomization Placebo

Drug Analyze PG+ as primary analysis

Analyze toxicity in all

Possible effect in the (-) group and/or toxicity in the (-) group needs to be evaluated because pre-treatment selection is not possible

Page 73: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

73

Targeted Therapy - Problems• Which target(s) is the target?

Herceptin target-gene amplification not protein “expression”

• Can’t measure the target – EGFR, her-2

• Can’t correlate target inhib. with outcome– Wrong target for the disease state– Target may not be in the disease pathway– Variable “expression” “over-expression”– Target present but non-functional or variable f(x)

• Can’t validate target – “Inconclusive” study design

Page 74: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

74

Cell Cycle Regulatory Pathways

Page 75: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

75

FDA Oncology Drug Approval

• Appropriate Endpoint• Appropriate Design• Appropriate Conduct (FDA will verify data)• Appropriate Analysis• Demonstrate Efficacy and Safety

(Benefit - Risk assessment)DDOP - NDA => Marketing Approval

DBOP - BLA => Biologics license

Page 76: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

76

General NDA Review Procedure for a New Drug

• Separate reviews by disciplines – stat, med, pharm-tox, Biopharm, CMC

• All primary data reviewed

• Analysis of Benefit versus Risk in the context of the disease process.

• Applications may be discussed before an advisory committee (ODAC) at an open public meeting

Page 77: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

77

Why Bad Things (non-approval)can happen to Good Drugs

Page 78: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

78

“Tortured Data Will Eventually Confess”

Some Examples of Clinical Trial Conduct “problems”– Inadequate or no controls– Missing or unclear selection/eligibility criteria– Small sample size - underpowered– Randomization process concerns– Lack of objective outcome assessment– Improper handling of dropouts– Inadequate adjustment for prognostic factors– Improper or misleading tables and graphs

Page 79: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

79

“Complementary and Alternative Statistics”

• Some improper statistical methods– Disregard of multiple comparisons– Improper (selective) censoring, exclusions– Post-hoc hypothesis selection (data-dredging) usually

on a subgroup analysis not pre-specified– Claiming subgroup results when the overall study fails

Page 80: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

80

notes• ODAC 1977:

– Approval to be based on survival or, possibly, improved quality of life

• Supreme Court 1979: US vs. Rutherford (Laetrile) – A drug is effective “if it … prolonged life,

improved physical condition, or reduced pain”• ODAC March 24, 1983:

– Reaffirmed above, and added “objective tumor response could also be used if a positive correlation between tumor response and: survival, QOL, or relief of pain could be shown.”

Page 81: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

81

FDA Website for Oncology Endpoints

www.fda.gov/cder/drug/cancer_endpoints/default.htm

FDA Guidances:

www.fda.gov/cder/guidance/index.htm

• Guidance on Effectiveness:http://www.fda.gov/cder/guidance/5506fnl.pdf

• Guidance on Oncology trials endpoints- draft

http://www.fda.gov/cder/guidance/6592dft.htm • Guidance on PRO - draft

http://www.fda.gov/cder/guidance/5460dft.htm

Page 82: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

82

23. This isn't an office. It's Hell with fluorescent lighting.

24. I started out with nothing & still have most of it left.

25. Sarcasm is just one more service we offer.

26. If I throw a stick, will you leave?

27. Errors have been made. Others will be blamed.

28. Whatever kind of look you were going for, you missed.

29. I'm trying to imagine you with a personality.

30. A cubicle is just a padded cell without a door.

31. Can I trade this job for what's behind door #1?

32. Too many freaks, not enough circuses.

33. Nice perfume. Must you marinate in it?

34. Chaos, panic, & disorder-- my work here is done.

35. How do I set a laser printer to stun?

36. I thought I wanted a career; turns out I just wanted a salary.

37. Oh I get it ... like humor ... but different

Page 83: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

83

11. I like you. You remind me of myself . . . when I was young andstupid.

12. You are validating my inherent mistrust of strangers.

13. I have plenty of talent and vision; I just don't give a damn.

14. I'm already visualizing the duct tape over your mouth.

15. I will always cherish the initial misconceptions I had about you.

16. Thank you. We're all refreshed and challenged by your unique pointof view.

17. The fact that no one understands you doesn't mean you're an artist.

18. Any connection between your reality and mine is purely coincidental.

19. What am I? Flypaper for freaks!?

20. I'm not being rude. You're just insignificant.

21. And your crybaby whiny-assed opinion would be...?

22. Do I look like a people person?

Page 84: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

84

Notes:Basis for New Drug Approval - NDA

• Demonstration of efficacy with acceptable safety in adequate and well-controlled studies CFR 314 - NDA Regs

• Ability to generate product labeling that– Defines an appropriate patient population for

treatment with the drug– Provides adequate information to enable safe

and effective use – prescribing of the drug

• Analogous rules for Biologics - BLA

Page 85: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

85

United States versus RutherfordUS Supreme court 442 US 544 (1979)

• A drug is effective “if it fulfills by objective indices, its sponsor’s claims of prolonged life, improved physical condition, or reduced pain,” and safe if the drug’s potential for inflicting death or physical injury is offset by the possibility of therapeutic benefit.

Page 86: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

86

notes• ODAC 1977:

– Approval to be based on survival or, possibly, improved quality of life

• Supreme Court 1979: US vs. Rutherford (Laetrile) – to be effective, a cancer drug must by objective indices,

improve survival, improve the quality of life, or relieve pain• ODAC March 24, 1983:

– Reaffirmed above, and added “objective tumor response could also be used if a positive correlation between tumor response and: survival, QOL, or relief of pain could be shown.”

• ODAC June 28, 1985: – Prolonged disease-free survival is an important goal

of adjuvant studies and is sufficient for approval of a drug for adjuvant therapy of breast cancer

Page 87: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

87

Notes

• FDA Modernization Act 1997: FDAMA– Created CFR 312 subpart E: Procedures to expedite

development for serious and life-threatening disease– Fast track – process for meeting with FDA– Priority review – 6 month NDA review time frame for

products addressing unmet medical need– Endorsed as possible one high quality study

• SPA – clinical protocols for phase 3 studies forming primary basis for efficacy for NDA; 45 d.

Page 88: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

88

FDAMA 1997 – one study for efficacy• 1998 FDA Guidance:

Characteristics of a single study to support effectiveness (with independent substantiation from related study data):a. Large, multicenter study

no single site or investigator disproportionately responsible for resultb. Consistency across study subsets

consistency across key subsets, i.e. severity of disease, stage, age

c. Multiple studies within the study – pairwise comparisons within the study

d. Multiple endpoints involving different eventssomewhat unrelated endpts i.e. MI and death

e. Statistically very persuasive – very low p values (not 0.045!)

Page 89: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

89

U.S. Legal Process

• Regulations: CFRs– Interpretations of laws – by the Executive Branch Departments – FDA Regs: Full power of laws when adopted

• Guidance: Issued by individual agencies (FDA or CDER) to reflect current thinking, not binding.

Page 90: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

90

Chemo-Prevention Endpoints

Current Approvals

Page 91: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

91

Reduction in cancer incidence

• Tamoxifen is approved:– to reduce the incidence of BC in women at

high risk for BC– In women with DCIS, following breast surgery

and RT, to reduce the risk of invasive BC– To reduce contralateral BC in patients

receiving adjuvant tamoxifen therapy for BC• Basis: Reduction in cancer incidence in RCT

Page 92: 1 FDA Oncology Drug Approval Endpoints, Effectiveness, and Approval Gerald H. Sokol MD, MS, FCP* and Robert Kane, MD, FACP Division of Drug Oncology Products

92

Reduction in polyp number

• Celecoxib approved to reduce the number of adenomatous colorectal polyps in FAP as an adjunct to usual care

• Basis:

• Reduction in polyp number

• Accelerated approval - RCT