Risk Assessment Best Practice - Development of a Cross

Risk Assessment Best Practice - Development of a Cross Pharma Work-flow for DP Nitrosamine Risk Assessment

Lhasa Brazil Webinar: 14th July 2021

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Mike Urquhart

Today’s Presentation

– Background to nitrosamines

– Development of a cross industry aligned approach to the nitrosamine assessment of drug products

– GSK experiences of using this workflow to perform drug product assessments

– Experiences relating to regulatory submissions

– Forward looking – potential alignment with ICH M7

Background

2017-2018 Valsartans (and Sartans)

– 2018 concerns were raised around the presence of N-nitroso impurities in sartan medications after NMDA and NDEA were detected in

some valsartan products

– Root causes: low level impurities formed during manufacture and not identified as risk during M7 RA

– Contamination traced to recycled solvents

– All sartans to be reviewed as considered high risk due to potential use of nitrosamine-generating chemistry in the synthesis

– EMA published new limits for common nitrosamines in sartans and agencies globally began testing sartan batches and publishing results

2019 General Requests for Nitrosamine Risk Assessments

– Companies to address risks of nitrosamines in all products, via a 3 step process

– Step 1: Risk assessment of all commercial products to define where there is risk

– Step 2: Confirmatory testing of drug products where risk is identified

– Step 3: Remediate (e.g. via controls or product/process changes) where a nitrosamine risk is confirmed

– Initially in EU, Switzerland and HC then requirements mirrored in US, China, S Korea, Brazil, Japan, Turkey……

– Tens of thousands of products (API and finished product) in scope

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Nitrosamines – how they form and areas of focus?

– Reaction of a vulnerable amine (secondary or tertiary) with a nitrosating agent (e.g. nitrous acid, nitrite / H+, alkyl nitrite)

– DS the main focus but there is a risk for the DP and assessment needs to involve both “science” and “quality”:

– Assessment of route and processes required as well as potential for cross contamination

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Drug Substance

Science

Reagent

Impurity / by-product

Part of DS scaffold

Quality

“Cross contamination”

Recycled solvents,

reagents or catalysts

Multipurpose equipment

Quality

“Cross contamination”

Recycled solvents,

reagents or catalysts

Multipurpose equipment

Science

Reagent


Part of DS scaffold

Science

Reagent


– Need to ensure all materials / reagent, impurities, and potential contaminants are included in assessment

– Note, nitrite is a known contaminant of potable water and so use of water can potentially be a source reagent if present with a secondary

amine under acidic conditions (OPRD paper written through pharma IQ consortium describes when further assessment is required)

– If formation is identified then need to consider downstream purge

Nitrosamine potential from nitrite present within water

Manuscript published in 2020 in OPRD

– Org. Process Res. Dev. 2020, 24, 1629−1646

Key messages:

– Levels of nitrite in water used in manufacture of

APIs are typically very low (<0.01 mg/L)

– This level of nitrite will not generally give rise to

significant levels of N-nitrosamines from basic

amines, such as dimethylamine, under typical

processing conditions

– Use of less basic amines, elevated temperature or

low pH conditions with “elevated” levels of nitrite

could lead to higher levels of N-nitrosamines:

– Greater impact if formed close to final API stage

– Tertiary alkyl amines generally not considered

likely to form nitrosamines from trace nitrite

– No identified potential if purified water is used as

nitrite levels are expected to be extremely low

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API Nitrosamine Assessment workflow developed

GSK a major contributor and published on the EFPIA Website as best practice guide.

https://efpia.eu/media/580594/workflows-for-quality-risk-management-of-nitrosamine-risks-in-medicines.pdf

Assessment focusses on:

1. Have any sources of N-nitrosamines or nitrosating agents been identified in the manufacturing processes or the

API itself?

2. Have any sources of secondary or tertiary amines been identified in the manufacturing processes or the API

itself, if they have then describe any accompanying risk of N-nitrosamine formation? (Assessment only required

if a source of nitrosating agent was identified in 1.)

3. Have any recovered / recycled materials or solvents been used during the registered manufacturing process?

4. Do the recovered / recycled materials or solvents that have been used during the registered manufacturing

process pose a cause for concern due to the potential for contamination with N-nitrosamines, nitrosating agents

or secondary / tertiary amines?

Any identified potential for formation leads to testing of API for nitrosamine of concern which could lead to manufacturing

process changes.

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Drug Product

Science (DS)

Part of DS scaffold

“Higher Potential”

Science (DP)

Impurity within excipients

“Higher Potential”

Science (DP)

Impurity in API / excipient

Amine excipient(?)

“Lower Potential”

Science (DS)

Impurity in DS

Part of DS scaffold

“Lower Potential”

Science (DS)

Impurity

in DS

Impurity derived from

packaging

– Factors for formation of nitrosamines in the DP are not well understood at this time:

– Excipients may contain nitrite (assume 5 ppm) – unusual for excipients to contain reactive amines

– Formulations range from dry and heterogenous to solution

– Potential formation from formulation, process and stability needs to be assessed as well as packaging (e.g. nitrocellulose)

Benefits of developing an industry aligned DP risk assessment work-flow

– Factors for the potential of nitrosamines within DP were not well understood

– Opportunity to learn from other scientists, company experiences as well as share literature knowledge

– Provide a robust process for risk assessment accessible for everyone

– Builds consistency of assessment across companies which gives assurance that appropriate rigour has been adopted

– The final risk assessment was reviewed across both EFPIA and IQ consortia – each company had a voice / was listened to

– Resulted in “best practice” guidance to DP risk assessment being published for all to use:

– https://efpia.eu/media/580594/workflows-for-quality-risk-management-of-nitrosamine-risks-in-medicines.pdf

What does the DP assessment process look like?

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IQ / EFPIA Drug product (DP) Workflow 1

Critique conditions of formulation for likelihood of nitrosation (e.g. pH, Temp, solution). Is nitrosation expected? (Y/N)

Guidance Note 4

Y

Risk identifiedTest DP for potential nitrosamine of concern

Present at ≥ agreed level (Y/N)Guidance Note 2

Y

Risk ConfirmedDocument / Report findings

Initiate change control (process and processing

materials)Verify change effectiveness

Guidance Note 10

Does the DS, or do the DP excipients, contain tertiary or secondary amines that could react with a nitrosating agent leading to a nitrosamine(s)? (Y/N)

Guidance Note 2

No risk identifiedProceed to packaging assessment

DP workflow 2

Y

N

N

Y

Does the DS, or do the DP excipients, contain a source of nitrosating agent e.g. nitrite? (Y/N)Guidance Note 3

Y

Seek guidance from safety group – extent of risk and levels for controlIs nitrosamine a potential mutagen? (Y/N)

Guidance Note 5

Calculate potential level of nitrosamine which could form. Is nitrosamine level ≥ agreed level? (Y/N)

Guidance Notes 6 and 8

Y

Consider Ames testing nitrosamine of concern. Is nitrosamine mutagenic / assumed to be mutagenic (Y/N)

Guidance Note 7

Y

N

N

N

N

N

Proceed to packaging assessmentDP workflow 2

Is there a risk for the DS or excipients to contain nitrosamines? (Y/N)

Guidance Note 1

Risk Confirmed

Proceed to DP workflow 3

N

Y


Risk identifiedTest DP for potential nitrosamine of concern

Present at ≥ agreed level (Y/N)Guidance Note 8


Initiate change control (process and processing materials)

Verify change effectivenessGuidance Note 10

N

Risk identifiedSeek guidance from safety group – extent of risk and

levels for control

(Is nitrosamine a potential mutagen and predicted to be above level of concern? (Y/N)

Guidance Note 5

Y

N

Y

Does packaging contain materials of concern? Is potential nitrosamine likely to be ≥ agreed levels (Y/N)

Guidance Note 9

N

Y

No risk identified

Document risk assessment output


Risk identifiedTest DS &/or excipients for potential nitrosamine

of concernPresent at ≥ agreed level (Y/N)

Guidance Note 8


Initiate change control (process and processing materials)

Verify change effectivenessGuidance Note 10

No risk identified

Proceed to DP workflow 1

Is there a risk for the DS or excipients to contain nitrosamines? (Y/N)

Guidance Note 1

Risk identifiedSeek guidance from safety group –extent of risk and levels for control

Is nitrosamine a potential mutagen (Y/N)

Guidance Note 5

N

Y

Y

N

N

Y

Proceed to DP workflow 1 box 2 (guidance note 2)

Accompanying Guidance notes

1. Is there a potential nitrosamine from the API or excipient?

2. Is there a source of amine within the API or excipient?

– Low level impurities are considered low potential for nitrosation

– Not all secondary amines are reactive toward nitrosation

– Tertiary amines are lower reactivity

3. Potential for containing a nitrosating agent?

– Excipients can contain trace nitrite

– Water for formulation generally no potential for formation

4. Could formulation process lead to potential nitrosation?

– Low pH (3 to 4) higher potential, pH > 7 “No potential”

– API aqueous solubility, water content of formulation

5. Understand safety limits for potential nitrosamine

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DP assessment for the potential of nitrosamines is complex

Guidance notes are provided offering cross pharma advice as how to best to move forward and includes both literature and scientific rationale



Accompanying Guidance notes (Continued)

6. Calculation of potential nitrosamine that could form versus provided ADI:

– No further action required if estimated level <ADI

8. Manufacture of a nitrosated marker of DP:

– Inability to manufacture a stable marker can justify no further action

– Use of literature to confirm whether nitrosation is likely / product stable

– Sample can be Ames tested to understand potential mutagenicity (Note 7)

– Testing DP with highest risk of NA formation should be the focus (formulation

and samples from manufacture through to end of shelf life)

9. Consider impact from packaging (nitrocellulose which could react from

amines within printing ink during heating sealing process):

– Generally considered to be very low

– Should consider multiple daily dosing

10. Mitigation to take should a nitrosamine be confirmed through testing:

– Could lead to re-formulation activities

– Any new product would need to be reassessed

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DP assessment for the potential of nitrosamines is complex

Guidance notes are provided offering cross pharma advice as how to best to move forward and includes both literature and scientific rationale



GSK Experiences – Practicalities

– DP workflow is a simple but robust approach to quickly understanding likely potential for nitrosamines

– Identifying presence of amines is key focus:

– Output from API risk assessment highlights potential amines for further assessment

– Understanding likelihood of presence of amines within excipients similarly important

– GSK have reviewed excipients from ~3000 suppliers:

– Created internal Excel database with output information

– Identified a limited number of excipients which have the potential presence of amines

– Reinforced excipient assessment by consideration of relevant monograph in Handbook of Pharmaceutical Excipients

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https://www.medicinescomplete.com/#/browse/excipients

GSK Experiences – Inform the Risk

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Likelihood of nitrosamine

formation in potential formulation

(reaction conditions)

Nitrite source

in formulation

In silico predictions

of toxicity Ames assayMarker synthesis & relevant

chemistry experiments to

understand formation

In vivo studyAnalysis in the

drug product

No risk if not present !

How much ?

Inform the risk

Iterative Process

Could lead to:

Substitution

Reformulation

Additives

Risk assessment

pH of formulation

API aq. solubility

Water content

Calculate potential levels

Versus daily dose

Justification

Expert knowledge

‘Read across’

Justification

Expert assessmentProvides ADI

Ease of synthesis

Reaction conditions used

Link to micro-reaction

conditions in formulation

Stability

Justification

Outcome &context

CoC nitrosamine, ICH M7 mutagen or non mutagenic

Confirm mutagenicity

Potential control limits (e.g. control to

ADI or ICH Q3B)

Method capability

Understanding throughout shelf life

Batch selection

Levels observed

Safety justification

GSK Experiences – Inform the Risk

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Likelihood of nitrosamine

formation in potential formulation

(reaction conditions)

Nitrite source

in formulation

In silico predictions

of toxicity Ames assayMarker synthesis & relevant

chemistry experiments to

understand formation

In vivo studyAnalysis in the

drug product

No risk if not present !

How much ?

Inform the risk

Iterative Process

Could lead to:

Substitution

Reformulation

Additives

Risk assessment

pH of formulation

API aq. solubility

Water content

Calculate potential levels

Versus daily dose

Justification

Expert knowledge

‘Read across’

Justification

Expert assessmentProvides ADI

Ease of synthesis

Reaction conditions used

Link to micro-reaction

conditions in formulation

Stability

Justification

Outcome &context

CoC nitrosamine, ICH M7 mutagen or non mutagenic

Confirm mutagenicity

Potential control limits (e.g. control to

ADI or ICH Q3B)

Method capability

Understanding throughout shelf life

Batch selection

Levels observed

Safety justification

Potential risk identified – estimation of likely levels of nitrite in excipients

– Use excipient specification detail for nitrite levels where available:

– Not generally captured within excipient specification

– Vitic Nitrite in excipients database:

– Provides a range of data for individual excipients

– To ensure a suitably conservative assessment the highest recorded level for nitrite is used for predictive purposes

– Where no excipient data is available a generic 5 ppm figure is used

– Testing of relevant excipient batches where a decision to progress to testing has been made:

– Output results can be used to understand potential factors for formation i.e. available nitrite versus observed nitrosamine (if detected)

– Provide any excipient testing results to Lhasa to build capability of the Vitic Nitrite in excipient database

Nitrites in Excipients Data Sharing Initiative

• Nitrates and nitrites are common nitrosating impurities that can be found in excipients, and therefore the level of risk

posed by these impurities needs to be established.

• Working closely together, Pharmaceutical industry and Lhasa Limited have established a database to help support

the assessment of the level nitrosamine risk.

• The aim is to develop a comprehensive and robust dataset of the shared analytical data, on level of nitrates and

nitrites in a broad range of excipients.

2020.1 2020.2 2020.1 2020.2N

um

ber

of

stu

die

s

Num

ber

of

excip

ients

Database updates

130

277

440

0

50

100

150

200

250

300

350

400

450

500

2021.1

23

54

64

0

10

20

30

40

50

60

70

2021.1

Database updates

• Vitic is the platform used to host the data

sharing initiative.

• Third database update was 5th March

2021 and data collection is ongoing.

• The database contains 440 studies for

64 excipients.

Potential risk identified – calculation for potential NDMA presence

50 mg tablet for a product with a 300 mg daily dose

50 mg tablets Potential Nitrite

Ingredient mg %ppm

(Lhasa Vitic DB)Wt (mcg) in single dose (50

mg)

API 70.0 23.4 0 0

Lactose monohydrate 70.0 23.4 1.7 0.12

Lactose anhydrous 140 46.7 <0.5 0.07

Microcrystalline Cellulose 15.5 5.2 2.38 0.04

Croscarmellose sodium 3 1.0 <0.5 0.001

Magnesium Stearate 1.5 0.5 4.6 0.01

Total 300 100.00 0.241

Safety limit for nitrosamine of concern (Computational Toxicology) = 96 ng per day

Estimated weight of nitrite in 300 mg daily dose = 0.241 x 6 = 1.45 mcg (0.0315 micromole)

Molecular weight of nitrite = 46

Molecular weight of NDMA = 74

Highest level of nitrosamine which could form from daily dose is 74/46 x 1.45 = 2.33 mcg (100% conversion)

Formulation “conversion factor” could be applied – NDMA level > 10% ADI even assuming only 1% conversion

Identified potential for nitrosamine formation at > ADI therefore testing recommended

– Step 2 confirmatory testing in progress

– Markers of nitrosated API being prepared where RA highlighted potential for nitrosamine formation

– Activated tertiary amine APIs which could potentially release low molecular weight nitrosamine if nitrosated generally

appear low potential for oral solid dose type formulations

– Activated amines include those with proximal aromatic and heteroaromatic rings or other functionality which would

facilitate loss of a nitrosamine if nitrosation was to occur

– Observation aligned with literature1 confirming tertiary amines are at least 1000 fold less reactive than secondary amines

Current status – High Level

1. S.S Mirvish; “Kinetics of dimethylamine nitrosation in relation to nitrosamine carcinogenesis” J. Nat. Cancer Inst.; 1970, 44 (3), 633 to 639

– Quantitative analysis (LC-MS/MS) of nitrosamine capabilities within GSK UK and US:

– Additionally using CROs for trace level analysis

– Ion chromatography systems also being used for nitrite analysis

– GSK experience that it takes typically 6-8 weeks to develop quantitative trace (ng/g) nitrosamine methods, plus validation

and testing

Learning:

– Analysis to such trace levels has significant difficulties with potential false positives:

– Trace DMF can give rise to a false positive for NDMA (use of second derivative to confirm peak):

– Can be other formamides from other dialkylamines

– Co-eluting impurity peaks at such low levels are an observed issue

– Potential for forming nitrosamine during the analytical preparation / on the column in low pH especially in presence of acetonitrile

– Overall analysis at such low levels in complex matrices brings difficulties per product.

– Important to understand analysis prior to reporting (Aligns with Health Canada Q&A)

Confirmatory testing at GSK

Where a potentially reactive amine is present within the formulation then discussion is required to inform the assessment

reviewer of the nature of the potential and provide a science based rationale why a conclusion of “there is, or isn’t” an

identified potential for nitrosamines can be made. The discussion includes:

– Relevance of the amine – likelihood of nitrosation?

– Potential pH of the DS / DP

– Solubility of the DS within the formulation

– Levels of water within the formulation (heterogeneity)

– Projection of levels of corresponding nitrosamine of concern from available levels of nitrite (Lhasa Vitic) if applicable

– Assessment conclusion

– Where potential for nitrosamine is identified, the RA would be updated with results from confirmatory testing once available

Assessment conclusions further reinforced by including supporting references to scientific literature

Important that an “unfamiliar” reviewer can follow the science based rationales which lead to the RA conclusion

Where there is no amine or nitrosating agent identified, it is appropriate to conclude no identified potential with

limited discussion

Output science based assessment – potentially reactive amine present

Regulatory activity (Commercial):

– Experience suggests that DP assessment with clear rationale is key

– Important to explain i) why it’s clear there is no risk or ii) if there is a risk then why is this

– Provide assessments for where potential for presence of nitrosamines has been identified

– Likely that stage 2 (Confirmatory testing) will lead to more regulatory interaction (understanding contributing factors)

– Look to provide a root cause when nitrosamines are detected

Regulatory activity (R&D):

– Recent marketing applications have included position for nitrosamine assessment:

– Acceptable to some authorities, others request provision of full assessment

– Assessment reports were requested for two products; and day 180 major objection raised which was later resolved

through provision of the assessment and accompanying discussion.

– Going forward and aligned with industry positioning, summary outcomes will be provided in Module 3, and the

assessment report will be attached to Module 1 for certain markets (e.g., EU, UK)

Experiences related to regulatory interactions

Future State

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CMC and Quality

– Continue to refine the assessment process and share knowledge of what constitutes a risk:

– GSK testing suggests tertiary amine API within an OSD is not generally a concern

– Follow the science – Use of further testing to understand risks associated with future APIs i.e. data on one API and DP should be used to

understand the risk associated with a different API and DP

– Where risks are identified, share outcome from root cause analysis with industry / regulators to better understand risk factors

Safety

– Chemistry: Structural basis of cohort of concern nitrosamines is well established

– Biology: An OECD compliant Ames test (where the experimental design has been tailored according to the chemical class)

is appropriate to understand mutagenicity without in vivo studies:

– Strong correlation of mutagenicity within the Ames test to observed rodent carcinogenicity (supports framework in ICH M7)

– Use of Ames test profile to understand potential mutagenicity i.e. confirmed CoC versus likely ICH M7 standard mutagen

– Thresholds of toxicological concern: Move to a safety and control position aligned with ICH M7:

– Is 18 ng per day an appropriate control for a potential nitrosated API or could a “still conservative” figure of 50 ng be considered?

– Nitrosamines are mutagens therefore use of less than life time approaches should be appropriate

– Follow the science – where an in vivo study is conducted, use of output data to assign an ADI1

1. E. Gocke & L. Muller; “In vivo studies in the mouse to define a threshold for the genotoxicity of EMS and ENU”; Mutat Res.; 2009, 678(2),

101 to 7 (doi: 10.1016/j.mrgentox.2009.04.005)

Conclusions and Acknowledgements

Summary

– Background to nitrosamines ✓

– Development of a cross industry aligned approach to

the nitrosamine assessment of drug products ✓

– GSK experiences of using this workflow to perform drug

product assessments ✓

– Experiences relating to regulatory submissions ✓

– Forward looking – potential alignment with ICH M7 ✓

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Acknowledgements

Andrew Lennard Amgen David Hobbs Lilly

Heather Akehurst AZ Justin Moser MSD

Ian Ashworth AZ Thomas Storm Novartis

Dawn Sievwright AZ Laurence Harris Pfizer

Fiona King GSK Ron Ogilvie Pfizer

Paul Trusty GSK Alain Sirvain Sanofi

Mike O'Sullivan GSK Nigel Hamilton Sanofi

Steve Hermitage GSK Rajesh Kamat Sanofi

Jim Harvey GSK Philip Lienbacher Takeda

Matt Popkin GSK Valeria Coscia Takeda

Mat Whiting GSK Tim Curran Vertex

Andy Whitehead GSK

Many thanks to Lhasa for the invitation and to you for your attention

Questions?

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Documents

Risk Assessment Best Practice - Development of a Cross