Silence Therapeutics (SLN) F-1Registration statement (foreign)

EXHIBIT 10.1

The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

Subject to Rules 1.5, 1.6, 1.7 and 18.3, the Grantor may from time to time grant Awards to Eligible Employees.

Subject to the Rules, the Grantor will in its absolute discretion decide whether or not any Awards are to be granted at any particular time and, if they are, to whom they are granted and the terms of such Awards. Where Awards are not granted by the Board, the terms must be approved in advance by the Board.

Where the Company has in place a binding Directors’ Remuneration Policy approved by the Company in a general meeting, the terms of an Award to be granted to an Eligible Employee who is a director of the Company must fall within the scope of the Directors’ Remuneration Policy most recently approved by the Company in a general meeting. Such terms may include by way of example but without limitation any relevant individual limit in Rule 3 and any Performance Target set under Rule 5.

An Award shall be granted by the Grantor passing a resolution. The Award Date shall be the date on which the Grantor passes the resolution or any later date specified in the resolution and allowed by Rule 1.5. The grant of an Award shall be evidenced by a deed executed by or on behalf of the person granting the Award.

An Award Certificate or a Restricted Share Agreement (as applicable) shall be issued to each Award Holder as soon as reasonably practicable following the grant of the Award setting out details of the Award determined in accordance with Rule 1.4 and, where applicable, Rule 1.12.

The Grantor shall, at the time of grant, determine:

Subject to Rule 1.6, the Grantor may grant Awards at any time after the date of adoption of the Plan.

Awards may not be granted:

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An Award may only be granted to an individual who is an Eligible Employee at the Award Date. Unless the Board decides otherwise, an Award will not be granted to an Eligible Employee who on or before the Award Date has given or received notice of termination of employment (whether or not lawful).

The Grantor may require an Eligible Employee who is (or is to be) granted an Award to confirm his acceptance of the Rules and the terms of any Award granted to him by a specified date. Such confirmation will be in a form set by the Grantor (which may require the Eligible Employee to execute a document). The Grantor may provide that the Award will lapse (and as a result be treated as never having been granted) if the confirmation of acceptance is not provided by the specified date.

An Award Holder may by notice in writing to the Company within 30 days after the Award Date say he does not want his Award in whole or part. In such a case, the Award shall to that extent be treated as never having been granted.

An Award Holder shall not be required to make payment for the grant of an Award unless the Board determines otherwise. Where an Award Holder refuses his Award pursuant to the terms of Rule 1.9, no payment in connection with the refusal is required from the Award Holder or the Grantor.

An Award shall be personal to the Award Holder and, except in the case of the death of an Award Holder, an Award shall not be capable of being transferred, charged or otherwise alienated and shall lapse immediately if the Award Holder purports to transfer, charge or otherwise alienate the Award.

This Rule 1.12 sets out specific provisions in relation to Restricted Shares.

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Subject to the terms of this Rule 2, Awards may be made under the Plan and the Non-Employee LTIP (taking account of Relevant Awards outstanding as at the Plan Restatement Date, but excluding any Relevant Awards that have been settled by the issuance of Plan Shares prior to the Plan Restatement Date) in an aggregate amount up to 8,700,000 Plan Shares (the Share Reserve). For the avoidance of doubt, the Plan and the Non-Employee LTIP shall be treated as a single equity award grant program for purposes of the Share Reserve, such that a grant under either the Plan or the Non-Employee LTIP shall be made from this single Share Reserve.

In addition, the Share Reserve will automatically increase on January 1st each year from 2021 and ending on (and including) January 1, 2028, in an amount equal to 5% of the total number of ordinary shares outstanding on December 31st of the preceding calendar year. Notwithstanding the foregoing, the Board may act prior to January 1st of a given year to provide that there will be no January 1st increase in the Share Reserve for such year or that the increase in the Share Reserve for such year will be a lesser number of Plan Shares than would otherwise occur pursuant to the preceding sentence.

Any increase to the Share Reserve (other than as set forth in the immediately preceding paragraph) must be approved by the passing of an ordinary resolution of the Company in general meeting, if required by applicable law.

If all or any part of a Relevant Award (whether granted before, on, or after the Plan Restatement Date) expires, lapses or is terminated, exchanged for cash, surrendered, repurchased or cancelled without having been fully exercised, in each case after the Plan Restatement Date, the unused Plan Shares covered by such Relevant Award will return to the Share Reserve and again be available for Awards. The following actions do not result in an issuance of Plan Shares and accordingly do not reduce the number of Plan Shares subject to the Share Reserve and available for issuance under the Plan: (i) the withholding of Plan Shares that would otherwise be issued to satisfy the exercise, strike or purchase price of an Award; or (ii) the withholding of shares that would otherwise be issued to satisfy a tax withholding obligation in connection with an Award.

The Share Reserve shall be subject to such adjustment as the Board may determine to be appropriate upon any Reorganisation.

If the granting of an Award would cause the limits in this Rule 2 to be exceeded, such Award shall take effect as an Award over the maximum number of Plan Shares which does not cause the limit to be exceeded. If more than one Award is granted on the same Award Date, the number of Plan Shares which would otherwise be subject to each Award shall be reduced pro rata.

The terms of Awards which may be made to any one Eligible Employee shall be limited as set out in this Rule 3.

A New Award must not be granted to an Eligible Employee if the result of granting the New Award would be that, at the proposed Award Date, the Market Value of the Plan Shares subject to that Award, when aggregated with the Market Value of the Plan Shares subject to any other New Award granted to him, that Time Vest in each Time Vesting Year in relation to the proposed New Award, would exceed 250% of his Annual Remuneration, subject to the Board determining that exceptional circumstances exist which justify the grant of an Award in excess of such limit in which case the limit shall be extended to not more than 300% of the relevant Eligible Employee’s Annual Remuneration.

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For the purpose of this Rule 3.2:

If the grant of an Award would cause the limit in Rule 3.2 to be exceeded, such Award shall take effect as an Award over the maximum number of Plan Shares which does not cause the limit to be exceeded.

The Award Price (if any) shall be determined by the Grantor and may be any price.

Where the Grantor has determined that an Award will be satisfied by the issue of new shares and the Award Price per Plan Share is less than the nominal value of a Plan Share, the Company will ensure that at the time of the issue of the Plan Shares arrangements are in place to pay up at least the nominal value of the relevant Plan Shares.

The Vesting of an Award and the extent to which it Vests will be subject to the satisfaction of any applicable Performance Target and any other conditions set by the Grantor on or before the Award Date.

Any Performance Target and any other conditions imposed under Rule 5.1 shall be:

If an event occurs which causes the Grantor to consider that any Performance Target and/or any other conditions imposed under Rule 5.1 subject to which an Award has been granted is no longer appropriate, the Grantor may substitute, vary or waive that Performance Target and/or any other conditions in such manner (and make such consequential amendments to the Rules) as:

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The Award shall then take effect subject to the Performance Target and any other conditions as substituted, varied or waived.

The Grantor shall, as soon as practicable, notify each Award Holder concerned of any determination made by it under this Rule 5.

Notwithstanding any other provision of the Rules, the Board may, at (or at any time before) the Vesting of an Award to which the Grantor has specified under Rule 1.4 that this Rule 6 applies, reduce the number of Plan Shares subject to an Award in whole or in part (including, for the avoidance of doubt, to nil) in the following circumstances:

and/or

In determining any reduction which should be applied under this Rule 6, the Board shall act fairly and reasonably but its decision shall be final and binding.

For the avoidance of doubt, any reduction under this Rule 6 may be applied on an individual basis as determined by the Board. Whenever a reduction is made under this Rule 6, the relevant Award shall be treated as having lapsed to that extent.

In this Rule 7, Trigger Events means:

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and/or

Notwithstanding any other provision of the Rules, if at any time during the period of two years (or such longer period as the Board considers is appropriate and has been notified to the Award Holder) following the Vesting of an Award to which the Board has specified under Rule 1.4 that this Rule 7 applies a Trigger Event occurs, then:

Where Rule 7.2 applies, the Board may in its absolute discretion require the relevant Award Holder to:

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less in each case the amount of tax and social security contributions actually paid (or due to be paid) by the Award Holder in respect of the acquisition of the Plan Shares and/or payment of cash in respect of an Award.

In addition to the obligation of the Award Holder as described above, the Award Holder shall use his best endeavours to seek and obtain repayment or credit from HMRC or any relevant overseas tax authority of the tax and social security contributions paid on the Award Holder’s behalf in relation to the Award as soon as reasonably practicable and to notify the Company of such claim and/or receipt of any credit or payment by HMRC (or any relevant overseas tax authority) in this regard. Following such notification the Company will be entitled to require the Award Holder to make a payment to it within 30 days of an amount equivalent to the amount of any payment or credit received from HMRC (or any relevant overseas tax authority).

By accepting the grant of an Award, the Award Holder authorises the Company or such other Group Member as may be the employer of the Award Holder to make deductions from any payment owing to him including but not limited to salary, bonus, holiday pay or otherwise in respect of any sum which would otherwise be payable by the Award Holder under this Rule 7.

Any transfers, payments or repayments to be made by the Award Holder under this Rule 7 shall be made within 30 days of the date the Award Holder is notified in writing of the transfer required or the amount due, as appropriate.

In addition to or in substitution for the actions described above that the Board may take under Rule 7.3 (the Actions), the Board may:

provided that the total amount represented by:

shall not, in the Board’s reasonable opinion, exceed the amount represented by any transfer and any amount or value which would have been due if the Board had only carried out the Actions.

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Where Rule 7.2 applies and the Award takes the form of an Option which the Award Holder has not exercised in full, the Board may in its absolute discretion reduce the number of Plan Shares subject to such Option (including, for the avoidance of doubt, to nil). In addition to or in substitution for reducing such Option, the Board may take any of the actions set out in Rules 7.7.1 to 7.7.4 provided that the total amount represented by reductions under Rules 7.7.1 to 7.7.4 and any reduction of the Option under this Rule 7.8 shall not, in the Board’s reasonable opinion, exceed the amount which would have been represented by the reduction of the Option only.

In carrying out any action under this Rule 7, the Board shall act fairly and reasonably but its decision shall be final and binding.

For the avoidance of doubt, any action carried out under this Rule 7 may be applied on an individual basis as determined by the Board. Whenever a reduction of an award, right to acquire Plan Shares or option is made under this Rule 7, the relevant award, right to acquire Plan Shares or option shall be treated to that extent as having lapsed.

The Board may determine at any time to reduce the number of Plan Shares subject to an Award (including, for the avoidance of doubt, to nil) either:

The value of any reduction under Rule 7.10.1 shall be determined in accordance with the terms of the relevant Clawback Provisions in the relevant Employees’ Share Scheme or bonus plan as interpreted by the Board in its absolute discretion.

The value of any reduction under Rule 7.10.2 shall be determined as if the terms of the relevant Clawback Provisions in the relevant Employees’ Share Scheme or bonus plan applied as interpreted by the Board in its absolute discretion.

Subject to Rules 5, 10 and 11, an Award will Vest on the later of:

The Grantor may determine that Vesting of the Award shall be delayed until any relevant investigation or other procedure relevant to an event falling within the scope of Rule 6 or Rule 7.10  has been completed.

Subject to the Rules, the effect of an Award Vesting shall be:

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Where the Vesting of an Award is prevented by any Dealing Restriction, the Vesting of that Award shall be delayed until the Dealing Restriction no longer prevents it. Plan Shares may not be issued or transferred to an Award Holder while Dealing Restrictions prevent such issue or transfer.  In the case of an Option, the Option may not be exercised while Dealing Restrictions prevent such exercise.

Subject to Rules 8.3, 8.4 and 15, a Vested Option may be exercised in whole or in part at any time. If exercised in part, the unexercised part of the Option shall not lapse as a result and shall remain exercisable until such time as it lapses in accordance with the Rules.

An Option shall be exercised by the Award Holder giving notice to the Grantor (or any person appointed by the Grantor) in the form from time to time prescribed by the Board, which may include (for the avoidance of doubt) any electronic and/or online notification.  Such notice shall specify the number of Plan Shares in respect of which the Option is being exercised, and be accompanied by either the Award Price (if any) in full or confirmation of arrangements satisfactory to the Grantor for the payment of the Award Price, together with any payment and/or documentation required under Rule 15 and, if required, the Award Certificate.

For the avoidance of doubt, the date of exercise of an Option shall be the later of the date of receipt of a duly completed valid notice of exercise (or any later date as may be specified in that notice of exercise) and the date of compliance with the requirements of the first paragraph of this Rule 8.6.

Subject to Rules 8.3, 8.8 and 15 and to any necessary consents and to compliance by the Award Holder with the Rules, the Grantor shall as soon as reasonably practicable and in any event not later than 30 days after:

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Subject to Rule 15, the Grantor may on exercise of an Option:

Subject to Rule 15, the Grantor may on the Vesting of a Conditional Share Award make a cash payment to the Award Holder equal to the Market Value of the Plan Shares in respect of which the Conditional Share Award has Vested, less the Award Price (if any).

Where the Company settles an Award in the manner described in this Rule 8.8, this shall be in full and final satisfaction of the Award Holder’s rights under the Award.

An Award (except an Award comprising Restricted Shares where the right to dividends has not been waived) may include the right to receive an amount in Plan Shares or cash on or following Vesting equal in value to the dividends which were payable on the number of Plan Shares in respect of which the Award has Vested during the period between the Award Date and the date of Vesting (or in the case of an Option the number of Plan Shares subject to the Option shall be increased as at the date of Vesting by the relevant value in Plan Shares).

The Grantor may determine at its absolute discretion whether or not the method used to calculate the value of dividends shall assume that such dividends have been reinvested into Plan Shares.

The Grantor may decide at any time not to apply this Rule 8.9 to all or any part of a special dividend or dividend in specie.

This Rule 8.10 shall apply to US Taxpayers to the extent necessary to avoid taxation under Section 409A of the US Internal Revenue Code of 1986, as amended, including any applicable regulations and guidance thereunder. Notwithstanding anything to the contrary contained in the Plan, no Option may be exercised later than 2.5 calendar months after the end of the Taxable Year in which the Option first becomes exercisable, provided that the Option shall lapse on the date it would have lapsed had this rule not applied. The Rules shall be interpreted accordingly.

For the purposes of this Rule 8.10, Taxable Year means the 12 month period in respect of which the Award Holder is obliged to pay US Tax or, if it would result in a longer exercise period, the 12 month period in respect of which the Award Holder’s employing company is obliged to pay tax. US Taxpayer means a person who is subject to taxation under the tax rules of the United States of America which does not include an Award Holder who is a non-resident alien throughout the period of participation in the Plan and who has no US workdays during such participation.

In this Rule 9:

Holding Period Holder means a trustee or nominee designated by the Grantor in accordance with this Rule 9; and

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Holding Period Shares means Plan Shares which are or were the subject of an Award to which a Holding Period applies and in respect of which the Holding Period has not ended in accordance with this Rule 9.

This Rule 9 applies to the extent that some or all of the Plan Shares acquired on Vesting of an Award (or exercise of an Option) are subject to a Holding Period.

Instead of arranging for the issue or transfer of the Holding Period Shares to the Award Holder on Vesting of a Conditional Share Award or exercise of an Option under Rule 8.7, the Board may arrange for the Holding Period Shares to be issued or transferred to the Holding Period Holder, as designated by the Board, to be held for the benefit of the Award Holder. Any balance of the Plan Shares in respect of which an Award Vests or is exercised will be issued or transferred as described in Rule 8.7.

If the Award took the form of Restricted Shares, the Holding Period Shares will be transferred to (or continue to be held by) the Holding Period Holder on the terms of this Rule 9.

The Award Holder or Holding Period Holder may not transfer, assign or otherwise dispose of any of the Holding Period Shares or any interest in them (and the Award Holder may not instruct the Holding Period Holder to do so) during the Holding Period except in the following circumstances:

Ceasing Relevant Employment during the Holding Period will have no impact on the provisions of this Rule 9, unless the Board decides otherwise, save where cessation is by reason of death in which case the Holding Period shall immediately be deemed to have ended.

For the avoidance of doubt, Rule 7 shall apply to the Holding Period Shares in the same way that it applies to any Plan Shares acquired by an Award Holder following Vesting of an Award or exercise of an Option which are not Holding Period Shares.

Subject to the provisions of this Rule 9, the Holding Period will end on the earliest of the following:

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If an Award Holder dies, a proportion of each Old Award held by him which has not Vested will Vest immediately. The proportion of each Old Award which shall Vest shall be determined by the Board at its absolute discretion taking into account such factors as the Board may consider relevant including, but not limited to, the satisfaction of any Performance Target as at the date of death and any other conditions imposed under Rule 5.1.

Alternatively, the Board may decide that an Old Award held by the Award Holder which has not yet Vested will continue until the normal time of Vesting in which case any Performance Target and/or any other conditions imposed under Rule 5.1 shall be considered at the time of Vesting.

In the case of an Old Option, if an Award Holder dies, his personal representatives (having established title to the satisfaction of the Company) shall be entitled to exercise the Vested proportion of his Option (whether Vested under this Rule or otherwise) at any time during the 12 month period following death, or, if later, following Vesting or, in either case, during such other period as the Board determines. The Option shall lapse at the end of such period.

If an Award Holder ceases to be in Relevant Employment by reason of:

any Old Award held by him which has not Vested will continue until the normal time of Vesting and the Performance Target and/or any other conditions imposed under Rule 5.1 shall be considered at the time of Vesting.

Alternatively, the Board may decide that an Old Award will Vest immediately in which case the proportion of the Award which shall Vest will be determined by the Board in its absolute discretion taking into account such factors as the Board may consider relevant including, but not limited to, the satisfaction of any Performance Target as at the time of cessation and any other conditions imposed under Rule 5.1.

In the case of an Old Option, the Award Holder shall be entitled to exercise the Vested proportion of his Option (whether Vested under this Rule or otherwise) at any time during the period ending 90 days following cessation of Relevant Employment or, if later, following Vesting or, in either case, during such other period as the Board determines. The Option shall lapse at the end of such period.

If it is proposed that an Award Holder, while continuing to be in Relevant Employment, should work in a country other than the country in which he is currently working and, by reason of the change, the Award Holder would:

an Award may, at the absolute discretion of the Board, Vest immediately either in full or to the extent determined by the Board in its absolute discretion and subject to such conditions as it may require taking into account such factors as the Board may consider relevant including, but not limited to, the period of time the relevant Award has been held and the extent to which any Performance Target and any other conditions imposed under Rule 5.1 have been met. Where the Award is an Option and has become Vested pursuant to this

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Rule 10.3, the Award Holder may exercise his Vested Option at any time during the period beginning 3 months before the proposed date of his transfer and ending 3 months after the date of his actual transfer. If not so exercised, the Option shall not lapse but shall cease to be treated as having Vested and shall continue in force in accordance with the Rules.

For the purposes of the Plan, an Award Holder shall not be treated as ceasing to be in Relevant Employment until he no longer holds any office or employment with any Group Member. In addition, unless the Board otherwise decides an Award Holder shall not be treated as so ceasing if within 7 days he recommences employment or becomes an office holder with any Group Member.

The Board may determine that an Award Holder will be treated as ceasing to be in Relevant Employment when he gives or receives notice of termination of his employment (whether or not lawful).

In the case of an Option:

Subject to Rule 12, where a person obtains Control of the Company as a result of making an offer to acquire Plan Shares, Awards shall Vest on the date the person obtains Control as set out below. Should a person (either alone or together with any person acting in concert with him) already have Control of the Company and makes an offer to acquire all of the ordinary shares in the capital of the company (or any shares representing them), other than those which are already owned by him, and such offer becomes wholly unconditional, Awards shall Vest on the date the offer becomes unconditional also as set out below.

The proportion of an Award which shall Vest will be determined by the Board in its absolute discretion taking into account such factors as the Board may consider relevant including, but not limited to, the time the Award has been held by the Award Holder and having regard to any Performance Target and/or any other conditions imposed under Rule 5.1. The proportion of an Award that the Board determines shall not Vest will lapse immediately except in the circumstances set out below.

In the case of an Option, the Vested proportion of the Option (whether Vested under this Rule 11.1 or otherwise) may be exercised at any time during the period of one month (or, if the Board determines a longer period shall apply, that period) beginning with the time when the person making the offer has obtained Control, or if the person already has Control, at the time when the offer to acquire all of the ordinary shares in the capital of the company (or any shares representing them) becomes wholly unconditional. The Option shall lapse at the end of such period unless the Board determines that a longer period for exercise shall apply, in which case the Option shall continue in force until the end of such extended period or until it otherwise lapses in accordance with the Rules.

If the extent of Vesting of an Award which Vests under this Rule 11.1 has been reduced by the Board to reflect the period of time that the Award has been held by the Award Holder, the Board may determine that Rule 12 shall apply to the proportion of the Award reflecting such reduction which has not Vested.

Subject to Rule 12, if a person becomes entitled or bound to acquire shares in the Company under sections 979 to 982 of the Companies Act 2006, Awards shall Vest as set out below.

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The proportion of an Award which shall Vest will be determined by the Board in its absolute discretion taking into account such factors as the Board may consider relevant including, but not limited to, the time the Award has been held by the Award Holder and having regard to any Performance Target and/or any other conditions imposed under Rule 5.1.

In the case of an Option, the Vested proportion of the Option (whether Vested under this Rule 11.2 or otherwise) may be exercised at any time during the period beginning with the date the person serves a notice under section 979 and ending 7 clear days before the date on which the person ceases to be entitled to serve such a notice. The Option shall lapse at the end of the 7 days.

If the extent of Vesting of an Award which Vests under this Rule 11.2 has been reduced by the Board to reflect the period of time that the Award has been held by the Award Holder, the Board may determine that Rule 12 shall apply to the proportion of the Award reflecting such reduction which has not Vested.

Subject to Rule 12, if a person proposes to obtain Control of the Company in pursuance of a compromise or arrangement sanctioned by the court under section 899 of the Companies Act 2006 Awards shall Vest on the date of the court sanction as set out below.

The proportion of an Award which shall Vest will be determined by the Board in its absolute discretion taking into account such factors as the Board may consider relevant including, but not limited to, the time the Award has been held by the Award Holder and having regard to any Performance Target and/or any other conditions imposed under Rule 5.1.

In the case of an Option, the Vested proportion of the Option (whether Vested under this Rule 11.3 or otherwise) may be exercised at any time during the period of one month (or, if the Board determines a longer period shall apply, that period) from the compromise or arrangement being sanctioned by the court. The Option shall lapse at the end of such period.

If the extent of Vesting of an Award which Vests under this Rule 11.3 has been reduced by the Board to reflect the period of time that the Award has been held by the Award Holder, the Board may determine that Rule 12 shall apply to the proportion of the Award reflecting such reduction which has not Vested.

If notice is given of a resolution for the voluntary winding-up of the Company, Awards shall Vest on the date notice is given.

The proportion of an Award which shall Vest will be determined by the Board in its absolute discretion taking into account such factors as the Board may consider relevant including, but not limited to, the time the Award has been held by the Award Holder and having regard to any Performance Target and/or any other conditions imposed under Rule 5.1.

In the case of an Option, the Vested proportion of the Option (whether Vested under this Rule 11.4 or otherwise) may be exercised at any time during the period of 6 months from the date of the notice or, if earlier, on completion of the winding up. The Option shall lapse at the end of such period.

The Board may determine that Awards Vest if it becomes aware that the Company will be affected by a demerger, distribution (which is not an ordinary dividend) or other transaction not otherwise covered by the Rules.

The proportion of an Award which shall Vest will be determined by the Board in its absolute discretion subject to such conditions as it may require taking into account such factors as the Board may consider relevant including, but not limited to, the time the Award has been held by the Award Holder and having regard to any Performance Target and/or any other conditions imposed under Rule 5.1.

In the case of an Option, the Vested proportion of the Option (whether Vested under this Rule 11.5 or otherwise) may be exercised at any time during a period as shall be determined by the Board. The Option shall lapse at the end of such period.

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If the extent of Vesting of an Award which Vests under this Rule 11.5 has been reduced by the Board to reflect the period of time that the Award has been held by the Award Holder, the Board may determine that Rule 12 shall apply to the proportion of the Award reflecting such reduction which has not Vested.

For the purpose of Rule 11 a person shall be deemed to have obtained Control of the Company if he and others Acting In Concert with him have together obtained Control of it.

For the purposes of this Rule 11, any reference to the Board shall be taken to be a reference to those individuals who were members of the Board immediately before the event by virtue of which this Rule 11 applies.

The Grantor shall, as soon as reasonably practicable, notify each Award Holder of the occurrence of any of the events referred to in this Rule 11 and explain how this affects his position under the Plan.

Where the Board is aware that an event is likely to occur under Rule 11:

the Board may, in its absolute discretion and by notice in writing to all Award Holders, declare that all Awards that are expected to Vest as a result of the relevant event shall Vest (and in the case of any such Award which is an Option, shall be exercisable) in accordance with Rule 11 during such period prior to the relevant event as determined by the Board.

An Award will not Vest under Rule 11 but will be exchanged for a new award (New Award) under this Rule to the extent that:

The following applies in respect of the New Award:

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Notwithstanding any other provision of the Rules, an Award shall lapse on the earliest of:

In the event of a Reorganisation, the number of Plan Shares subject to an Award which is an Option or a Conditional Share Award, the description of the Plan Shares, the Award Price or any one or more of these shall be adjusted in such manner as the Grantor, together with the Board where relevant, shall determine.

In the case of Restricted Shares, subject to the relevant Restricted Share Agreement, the Award Holder shall have the same rights as any other shareholder in respect of Restricted Shares in the event of a Reorganisation. Any shares, securities or other rights allotted to an Award Holder for no consideration or with the proceeds of sale of such rights (but not with new consideration provided by the Award Holder) as a result of such Reorganisation shall be treated as if they were awarded to the Award Holder at the same time as the Restricted Shares in respect of which the rights were conferred and subject to the Rules and the terms of the Restricted Share Agreement.

No adjustment shall be made to the Award Price which would result in the Plan Shares subject to an Option or Conditional Share Award being issued at a price per Plan Share lower than the nominal value of a Plan Share except where the Grantor puts in place arrangements to pay up the nominal value at the date of issue of the Plan Shares (or the difference between the adjusted Award Price and the nominal value as the case may be).

The Grantor shall, as soon as reasonably practicable, notify each Award Holder of any adjustment made under this Rule 14 and explain how this affects his position under the Plan.

Unless the Award Holder discharges any liability that may arise himself, the Grantor, the Company or any Group Member or former Group Member (as the case may be) may withhold such amount, or make such other arrangements as it may determine appropriate, for example to sell or withhold Plan Shares, to meet any liability to taxes or social security contributions in respect of Awards, including, where applicable, Employer’s NIC

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transferred under 15.2. The Award Holder will be responsible for all taxes, social security contributions and other liabilities arising in respect of the Award Holder’s Awards.

The Grantor may, at its discretion and to the extent permitted by law, require the Award Holder to pay all or any part of the Employer’s NIC in relation to an Award.

The Grantor may require an Award Holder to execute a document in order to bind himself contractually to any such arrangement as is referred to in Rules 15.1 and 15.2 and return the executed document to the Company by a specified date. It shall be a condition of Vesting, and where applicable exercise, of the Award that the executed document be returned by the specified date unless the Grantor determines otherwise.

The Board may, at its discretion, determine that an Option may not be exercised and/or the Plan Shares subject to a Conditional Share Award and/or the Plan Shares the subject of an Award comprising Restricted Shares may not be issued or transferred to the Award Holder (or for his benefit) unless the Award Holder has beforehand signed an election under Chapter 2 of Part 7 of ITEPA 2003 and/or section 165 of the Taxation of Chargeable Gains Act 1992 or entered into broadly similar local arrangements.

Except as set out in Rule 1.12 (Restricted Shares), all Plan Shares issued or transferred under the Plan shall, as to voting, dividend, transfer and other rights, including those arising on a liquidation of the Company, rank equally in all respects and as one class with the shares of the same class in issue at the date of issue or transfer save as regards any rights attaching to such Plan Shares by reference to a record date prior to the date of such issue or transfer.

If and so long as Plan Shares are listed on the Official List and traded on the London Stock Exchange, the Company will apply for the listing and admission to trading of any Plan Shares issued under the Plan as soon as reasonably practicable.

Notwithstanding any other provision of the Plan:

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

By accepting the grant of an Award, an Award Holder is deemed to have agreed to the provisions of these Rules, including this Rule 17.

The Board (and the Grantor, where appropriate) shall be responsible for, and shall have the conduct of, the administration of the Plan. The Board may from time to time make, amend or rescind regulations for the administration of the Plan provided that such regulations shall not be inconsistent with the Rules.

The decision of the Board shall be final and binding in all matters relating to the Plan, including but not limited to the resolution of any dispute concerning, or any inconsistency or ambiguity in the Rules or any document used in connection with the Plan.

Where the Grantor is not the Company and has granted, or proposes to grant, an Award, the Grantor shall consult with, and take into account the wishes of, the Board before making any determination or exercising any power or discretion under the Plan.

All Awards shall be granted entirely at the discretion of the Grantor.

An Award Holder and, where the Grantor is not the Company, the Grantor shall provide to the Company or any Group Member as soon as reasonably practicable such information as the Company reasonably requests for the purpose of complying with its obligations under section 421J of ITEPA 2003 or similar requirements of local tax legislation.

The cost of introducing and administering the Plan shall be met by the Company. The Company shall be entitled, if it wishes, to charge an appropriate part of such cost and/or the costs of an Award to a Subsidiary or the Grantor.

The Company and any Group Member will process an Award Holder’s personal data in accordance with the applicable data privacy policy or policies adopted by the Company and any data privacy notice(s) provided to an Award Holder covering the processing of the Award Holder’s data in connection with the Plan.

Nothing in these Rules confers any benefit, right or expectation on a person who is not an Award Holder. No such third party has any rights under the Contracts (Rights of Third Parties) Act 1999 to enforce any terms of these Rules.

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

Subject to Rule 19.2, the Board may from time to time amend the Rules (including, for the purposes of establishing a sub-plan for the benefit of employees located overseas).

An amendment may not materially adversely affect the rights of an existing Award Holder except:

Save as provided for by law, any notice, document or other communication given by, or on behalf of, the Grantor or to any person in connection with the Plan shall be deemed to have been duly given if delivered to him at his place of work, if he is in Relevant Employment, if sent by e-mail to such e-mail address as may be specified by him from time to time or, in the case of an Award Holder who remains in Relevant Employment, to such e-mail address as is allocated to him by any Group Member, or sent through the post in a pre-paid envelope to the postal address last known to the Company to be his address and, if so sent, shall be deemed to have been duly given on the date of posting.

Save as provided for by law, any notice, document or other communication so sent to an Award Holder shall be deemed to have been duly given notwithstanding that such Award Holder is then deceased (and whether or not the Company has notice of his death) except where his personal representatives have established title to the satisfaction of the Company and supplied to the Company an e-mail or postal address to which notices, documents and other communications are to be sent.

Save as provided for by law any notice, document or other communication given to the Grantor (or any relevant person appointed by the Grantor) in connection with the Plan shall be delivered by hand or sent by email, fax or post to the Company Secretary (or any relevant person appointed by the Grantor) at the Company’s registered office (or such other e-mail or postal address as may from time to time be notified to Award Holders) but shall not in any event be duly given unless it is actually received at the registered office or such e-mail or postal address.

The formation, existence, construction, performance, validity and all aspects whatsoever of the Plan, any term of the Plan and any Award granted under it shall be governed by English law.

The English courts shall have jurisdiction to settle any dispute which may arise out of, or in connection with, the Plan.

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

The jurisdiction agreement contained in this Rule 21 is made for the benefit of the Company only, which accordingly retains the right to bring proceedings in any other court of competent jurisdiction.

By accepting the grant of an Award, an Award Holder is deemed to have agreed to submit to such jurisdiction.

In this Plan, unless the context otherwise requires, the following words and expressions have the following meanings:

Acting In Concert has the meaning given to that expression in The City Code on Takeovers and Mergers in its present form or as amended from time to time;

Award means an Option, a Conditional Share Award or Restricted Shares granted under the Plan;

Award Certificate means a statement in a form, which may include an electronic form, determined by the Company setting out details of an Award which is an Option or a Conditional Share Award determined in accordance with Rule 1.4;

Award Date means the date on which an Award is granted in accordance with Rule 1.3;

Award Holder means an individual who holds an Award or, where the context permits, his legal personal representatives. Where relevant, Award Holder(s) shall include reference to former Award Holder(s);

Award Price means the amount (if any), expressed either as an amount per Plan Share or a total amount, payable in respect of the exercise of an Option 0r Vesting of a Conditional Share Award or for the acquisition of Restricted Shares under a Restricted Share Agreement, determined in accordance with Rule 4;

Board means, subject to Rule 11.7, the board of directors of the Company or a duly authorised committee of it or a person duly authorised by the board of directors of the Company or such committee;

Company means Silence Therapeutics plc incorporated in England and Wales under company number 02992058;

Conditional Share Award means a conditional right under the Plan to acquire Plan Shares;

Confidential Information means all information of a confidential nature, whether provided before or after the date of adoption of the Plan, relating to a Group Member, whether in writing, orally communicated, in electronic format or otherwise, and including any such information obtained through discussions with directors, officers, members of management or employees of a Group Member together with any reports, analyses, compilations, studies, copies, databases or other materials or documents prepared by the party receiving such information to the extent incorporating such information (or any part of such confidential information).

Control has the meaning given to it by section 995 of ITA 2007;

Dealing Day means any day on which the London Stock Exchange is open for the transaction of business;

Dealing Restrictions means any restrictions imposed by legislation, regulation or any other code or guidance on share dealing with which the Company seeks to comply;

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

Directors’ Remuneration Policy has the meaning given to it by section 422A(6) of the Companies Act 2006;

Eligible Employee means an individual who at the Award Date is an employee of a Group Member;

Employees’ Share Scheme has the meaning set out in section 1166 of the Companies Act 2006;

Employer’s NIC means employer’s secondary class 1 National Insurance contributions liability or any local equivalent;

Exercise Period means the period set by the Board on the Award Date during which an Option may be exercised, ending no later than the 10th anniversary of the Award Date;

Financial Conduct Authority means the “competent authority” as that expression is defined in Part VI of the Financial Services and Markets Act 2000;

Gain means the difference between (i) the Market Value of a Plan Share on the date of exercise of an Option and (ii) the Award Price, multiplied by the number of Plan Shares in respect of which the Option is being exercised;

Grantor means:

Group means the Company and its Subsidiaries from time to time and Group Member shall be interpreted accordingly;

HMRC means Her Majesty’s Revenue & Customs;

Holding Period means the period (if any) specified under paragraph 9 of Rule 1.4 (commencing from the Vesting Date of the relevant Award) during which the restrictions contained in Rule 9 apply;

ITA 2007 means the Income Tax Act 2007;

ITEPA 2003 means the Income Tax (Earnings and Pensions) Act 2003;

London Stock Exchange means the London Stock Exchange plc or any successor body;

Market Value on any day means:

New Award means an Award granted on or after 1 October 2019;

New Option means an Option granted on or after 1 October 2019;

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

Non-Employee LTIP means the Silence Therapeutics plc 2018 Non-Employee Long Term Incentive Plan and the US Sub-Plan thereto;

Official List means the list maintained by the Financial Conduct Authority in accordance with section 74(1) of the Financial Services and Markets Act 2000 for the purposes of Part VI of the Act;

Old Award means an Award granted before 1 October 2019;

Old Option means an Option granted before 1 October 2019;

Option means a right to acquire Plan Shares granted under the Plan;

Performance Target means a performance target imposed as a condition of the Vesting of an Award under Rule 5.1 and as substituted or varied in accordance with Rule 5.3;

Plan means the Silence Therapeutics plc 2018 Long Term Incentive Plan as amended from time to time;

Plan Restatement Date means 23 July 2020;

Plan Shares means ordinary shares in the capital of the Company (or any shares representing them);

Regulatory Information Service means a service that is approved by the Financial Conduct Authority on meeting the Primary Information Provider criteria and is on the list of Regulatory Information Services maintained by the Financial Conduct Authority (or any overseas equivalent);

Relevant Employment means employment with any Group Member;

Relevant Award means (i) an Award granted under the Plan, the Schedule, and the US Sub-Plan to the Plan; and/or (ii) an Award granted under the Non-Employee LTIP;

Reorganisation means any variation in the share capital of the Company, including but without limitation a capitalisation issue, rights issue, demerger or other distribution, a special dividend or distribution, rights offer or bonus issue and a sub-division, consolidation or reduction in the capital of the Company;

Restricted Shares means Shares where the Award Holder is the beneficial owner of the Plan Shares from the Award Date subject to the Restricted Share Agreement;

Restricted Share Agreement means the agreement referred to in Rule 1.12;

Rules mean the rules of the Plan;

Share Reserve has the meaning given to it in Rule 2.1;

Subsidiary has the meaning set out in section 1159 of the Companies Act 2006;

Trustees means the trustees of any trust created by a Group Member which, when taken together with the Plan, constitutes an Employees’ Share Scheme;

Vest means:

Vesting Period means the period from the Award Date to the normal date of Vesting.

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

In the Plan, unless otherwise specified:

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

SCHEDULE

CSOP Options

The purpose of this Schedule is to provide, in accordance with Schedule 4, benefits for employees in the form of CSOP Options. The Board may, when granting an Option to a CSOP Employee, designate it as a CSOP Option. If they do so, the provisions of the Silence Therapeutics plc 2018 Long Term Incentive Plan (the “Plan”) will apply to it, as amended by this Schedule.

Words used in this Schedule have the same meaning as in the Plan unless amended as stated below:

Award Date has the meaning given in paragraph 3.2 of this Schedule;

Control has the meaning given in s995 Income Tax Act 2007 of the United Kingdom;

CSOP Employee means an employee of a Participating Company but does not include anyone who is:

CSOP Market Value in relation to a Share on a particular day means:

and any restriction referred to in paragraph 4(c) will be ignored when determining CSOP Market Value;

CSOP Option means an Option to which this Schedule applies;

HMRC means Her Majesty’s Revenue and Customs of the United Kingdom;

ordinary share capital has the meaning given in s989 Income Tax Act of the United Kingdom;

Participating Company means:

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

Recognised Stock Exchange has the meaning given in s1005 of the Income Tax Act 2007 of the United Kingdom¹;

Schedule 4 means Schedule 4 to the Income Tax (Earnings and Pensions) Act 2003 of the United Kingdom;

Schedule 4 Plan means a plan in relation to which the requirements of Parts 2 to 6 of Schedule 4 are (and are being) met;

Shares means, subject to paragraph 2, ordinary shares in the capital of the Company which satisfy paragraphs 16 to 20 of Schedule 4;

Subsidiary means a company which is a subsidiary of the Company within the meaning of s1159 Companies Act 2006 of the United Kingdom which is under the Control of the Company; and

Takeover Offer means either:

and for these purposes the reference to the "whole of the issued ordinary share capital" and "all the Shares" shall not be taken to include any capital or Shares held by the person making the offer or a person connected with that person (within the meaning of s718 Income Tax (Earnings and Pensions) Act 2003 of the United Kingdom), and it does not matter whether the offer is made to different shareholders by different means.

If any Shares which are subject to a CSOP Option cease to satisfy paragraphs 16 to 20 of Schedule 4 and this Schedule is to cease to be a Schedule 4 Plan, or the CSOP Options become exercisable pursuant to paragraph 10.5, the definition of “Shares” above is changed automatically to “ordinary shares in the capital of the Company”.  A CSOP Option may not otherwise be exercised after the Shares to which it is subject cease to satisfy paragraphs 16 to 20 of Schedule 4.

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

The Company will ensure that the Participant is notified of the following as soon as practicable after grant of a CSOP Option:

The notification may be given wholly or partly through the Award Certificate relating to the CSOP Option.

The Award Price of a CSOP Option will not be less than CSOP Market Value of a Share on the date of grant.

The aggregate CSOP Market Value of:

Adjustments may be made to CSOP Options under Rule 14 (Adjustment of Awards on Reorganisation) only where there is a variation of the share capital of which Shares form part and:

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

An annual return relating to the Plan (as amended by this Schedule) submitted to HMRC following any such adjustment must include a declaration that the Plan (as amended by this Schedule) continues to comply with Schedule 4.

A Participant may not exercise a CSOP Option while he is excluded from participation in a Schedule 4 Plan under paragraph 9 of Schedule 4 (material interest provisions).

The provisions of this paragraph 10 have effect in addition to any provisions in Rule 11 (Takeover and other corporate events). Notwithstanding the foregoing, no such provision provided in Rule 11 shall have effect if it would affect the status of the Plan as amended by this Schedule as a Schedule 4 Plan unless it is determined that the Plan as amended by this Schedule should cease to be a Schedule 4 Plan.

If any person obtains Control of the Company as a result of making a Takeover Offer the Vested proportion of any CSOP Options (whether Vested under Rule 11.1 (Takeover) or otherwise) may, subject to paragraph 10.4, be exercised within one month (or, if the Board determines a longer period not exceeding six months shall apply, that period) after the time when the person making the offer has obtained Control of the Company and any conditions subject to which the Takeover Offer is made have been satisfied.

If the court sanctions under s899 Companies Act 2006 a compromise or arrangement applicable to or affecting:

the Vested proportion of any CSOP Options (whether Vested under Rule 11.3 (Scheme of arrangement) or otherwise) may, subject to paragraph 10.4, be exercised within one month (or, if the Board determines a longer period not exceeding six months shall apply, that period) after the date of that court sanction.

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The Silence Therapeutics plc 2018 Employee Long Term Incentive Plan

If paragraph 10.2 or 10.3 applies and, as a result of the event by virtue of which that paragraph applies, Shares in the Company would no longer meet the requirements of Part 4 of Schedule 4, the Board, acting fairly and reasonably, may decide that the CSOP Options may be exercised under that paragraph only within a 20 day period after the relevant event.

Where a CSOP Option becomes exercisable pursuant to this paragraph 10, if it is not exercised by the end of the period specified for exercise it shall then lapse (save where paragraph 9.2 applies).

The Board’s powers under the Plan are further restricted in relation to CSOP Options as described in this paragraph.

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