The European Society of Pathology initiative

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Pathology & Medical Biology University Medical Center Groningen

First EQA Results for PD-L1

EQA pilot of the ESP

Nils ‘t Hart

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Pilot scheme for PD-L1

• Technical as well as interpretation EQA

• 1

^ste

round

(March/April 2017)

3 cases, staining+interpretation

• 2

^nd

round

(June/July 2017)

digital cases, interpretation only

• 3

^e

round

(Okt/September 2017)

3 cases, staining+interpretation

• Assessment by al least two trained pathologists for

clone 22c3 and SP142

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N labs % (n=84)

22C3 (Dako) 50 60%

SP263 (Ventana) 9 11%

E1L3N (cell signaling) 9 11%

28-8 (Dako/Abcam) 6 7%

SP142 (Ventana) 3 4%

QR1 (Quartett Biotechnology) 3 4%

CAL10 (Biocare Medical) 3 4%

• 84 labs submitted results

• 27 countries

General Data ESP PD-L1 (pilot)

Table: used antibodies EQA March/April 2017.

In red antibodies that are not discribed for known drugs

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N labs % (n=84)

CC1, basic pH (Ventana) 37 44%

EnVisionFLEX Target Retrieval

Solution, acidic pH (Dako) 24 29%

Other 23 27%

Used Methods

Detection and enhancement

N labs % (n=84) OptiView DAB IHC Detection Kit (Ventana) 30 36%

EnVision flex / EnVision (DAKO) 27 32%

Bond polymer refine detection system (Leica) 10 12%

UltraView Universal DAB Detection kit (Ventana) 8 10%

Other 8 10%

Antigen retrieval

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Which Clone for which Drug?

Pem. Nivo. Atezo. Durv. ? total

22c3 42 13 1 1 8 ₆₇

28-8 1 2 3 ₆

SP142 1 2 1 ₄

SP263 3 6 3 4 2 ₁₈

E1L3N,

CAL10, QR1 11 6 2 1 4 ₂₄

total 57 28 8 6 18

Table: in green PharmDx antibodies that are approved for either NSCLC or urothelial carcinoma. Note: table shows PharmDx as well as LDT tests.

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Preliminary results of first PD-L1 pilot round?

Case 1 Case 2 Case 3 Tonsil Positive 8 (10%) 81 (96%) unknown* unknown*

Negative 76 (90%) 3 (4%) unknown* unknown*

Not contributive 0 (0%) 0 (0%) 3 (4%) unknown*

Table: unknown* marks cases that are not corrected for the used scoring system. Tonsil needs to be scored by assessors.

Case 1 included as clearly negative (no PD-L1 expression) Case 2 included as clearly positive (>90% expression) Case 3 included as an intermediate case

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A few remarks…

(UMCG data instead of ESP EQA data)

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PD-L1 22c3 Dako PD-L1 22c3 Ventana

Tonsil control differs between platforms

and protocols

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>50%+ PD-L1

(UMCG data)

Ventana Ventana Ventana

Ventana

Dako Dako

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>50%+ PD-L1

(UMCG data)

Ventana

Dako Dako

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Focal weak expression of PD-L1

(UMCG data)

Ventana

Dako Dako

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Focal weak expression of PD-L1

(UMCG data)

Ventana

Dako Dako

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PD-L1 issues

(UMCG data)

22c3 PharmDx

Dako Link-48 22c3 LDT

Ventana Ultra

• The tonsil control was approved

• Two cores are clearly discordant, no explanation was found

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Concluding

• EQA pilot showed many different PD-L1 approaches

• EQA providers need to consider that differences in expression are obvious due to differences in used

platforms, interpretation of results are more important

• Differences in platforms might result in discordant results due to a so-called “critical case”

– A critical case is not shown in UMCG-TMA yet

(work in progress)

– EQA providers need to look for “critical cases”

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Pathology & Medical Biology University Medical Center Groningen Technicians:

Tom Artz

Claudia Kempenga Pathologist:

Wim Timens Nils ‘t Hart Leuven team:

Cleo Keppens Kelly Dufraing Veronique Tack Els Dequeker Assessors:

Patrick Pauwels Ales Ryska

Nils ‘t Hart

ESP QA foundation

Raed Al Dieri, scientific director