Convertible Loan Notes	6 Months Ended
Jun. 30, 2024
Debt Disclosure [Abstract]
Convertible Loan Notes	10. Convertible loan notes Novartis Loan Note On February 10, 2020, the Company entered into a convertible equity financing with Novartis Pharma (AG) (“Novartis”) under which Novartis purchased a £3.8 million ($5.2 million) convertible loan note (the “Novartis Loan Note”). The Novartis Loan Note is convertible at the discretion of the holder, at a fixed price of £0.265 per ordinary share and originally bore interest at 6% per annum with a maturity date of February 10, 2023. In connection with the Novartis Loan Note, the Company also issued 1,449,614 warrants which are exercisable until February 2025 at an exercise price of £0.265 per ordinary share. These warrants were recognized separately as equity instruments. Effective February 10, 2023, the maturity date of the Novartis Loan Note was extended to February 10, 2025 and the interest rate amended to 9%. Interest accrued to the amendment date of $0.9 million was paid in cash, and additional warrants to purchase 2,000,000 ordinary shares were issued. These warrants were also recognized separately as equity instruments. The amendments to the Novartis Loan Note were an extinguishment of the original instrument and the issuance of a new one. Accordingly, on the extinguishment date, the carrying value of $5.5 million was derecognized. At the same time, a new liability of $3.4 million was recognized, which represents the portion of the consideration of the new arrangement allocated to the liability component of the new Novartis Loan Note on the basis of its relative fair value, net of fees. The remaining amount was allocated between the $0.9 million of interest paid in cash and the residual $1.2 million which was recorded in additional paid-in capital to reflect the relative fair value of the warrants and the conversion option embedded in the new Novartis Loan Note. No extinguishment gain or loss was recognized. The Company recognized interest expense of $0.3 million and $0.6 million in relation to the Novartis Loan Note in the unaudited condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2024, respectively and $0.2 million and $0.5 million in the three and six months ended June 30, 2023 respectively. The effective interest rate applied to the liability portion of the Novartis Loan Note in the three and six months ended June 30, 2024 was 27.8% (2023: 27.8% after the amendments and 37.4% before). As of June 30, 2024 and December 31, 2023, the net carrying amount of the liability component of the convertible debt instrument was $4.9 million and $4.4 million, respectively and the fair value was $3.3 million and $3.1 million, respectively. Private Placement Loan Notes The Private Placement Loan Notes were issued in 2020 as part of a $70.0 million private placement transaction which also included the issuance of ordinary shares and warrants. The Private Placement Loan Notes were originally convertible at a fixed price of £0.174 per ordinary share, bore interest at a rate of 6% per annum and had a maturity date of June 3, 2023. In May 2023, the maturity date of the Private Placement Loan Notes was extended to August 3, 2023, with all other terms remaining unchanged. This extension was a modification and the carrying value of the liability component was adjusted to the present value of the modified cash flows discounted at the original effective interest rate, net of identifiable transaction costs. The carrying value was also reduced by $0.6 million with a corresponding adjustment to additional paid-in capital to reflect the increase in the fair value of the embedded conversion option. In 2023, the Company received conversion notices and subsequently issued and allotted 17,774,895 ordinary shares in the three months ended June 30, 2023 and 9,645,200 ordinary shares in the three months ended September 30, 2023, both at a price of £0.174 per share on non-cash conversion of Private Placement Loan Notes with an aggregate principal amount of $4.6 million. In 2023, the Company also paid $3.2 million to fully settle the outstanding principal and accrued interest balance. The Company recognized $0.7 million and $1.1 million of interest expense in the three and six months ended June 30, 2023 respectively. The effective interest rate applied to the liability portion of the Private Placement Loan Notes in 2023 after the amendments was 27.1% while the effective interest rate applied in 2023 before the amendments was 25.1%.

Convertible Loan Notes

6 Months Ended

Jun. 30, 2024

10. Convertible loan notes

Novartis Loan Note

On February 10, 2020, the Company entered into a convertible equity financing with Novartis Pharma (AG) (“Novartis”) under which Novartis purchased a £3.8 million ($5.2 million) convertible loan note (the “Novartis Loan Note”). The Novartis Loan Note is convertible at the discretion of the holder, at a fixed price of £0.265 per ordinary share and originally bore interest at 6% per annum with a maturity date of February 10, 2023. In connection with the Novartis Loan Note, the Company also issued 1,449,614 warrants which are exercisable until February 2025 at an exercise price of £0.265 per ordinary share. These warrants were recognized separately as equity instruments.

Effective February 10, 2023, the maturity date of the Novartis Loan Note was extended to February 10, 2025 and the interest rate amended to 9%. Interest accrued to the amendment date of $0.9 million was paid in cash, and additional warrants to purchase 2,000,000 ordinary shares were issued. These warrants were also recognized separately as equity instruments.

The amendments to the Novartis Loan Note were an extinguishment of the original instrument and the issuance of a new one. Accordingly, on the extinguishment date, the carrying value of $5.5 million was derecognized. At the same time, a new liability of $3.4 million was recognized, which represents the portion of the consideration of the new arrangement allocated to the liability component of the new Novartis Loan Note on the basis of its relative fair value, net of fees. The remaining amount was allocated between the $0.9 million of interest paid in cash and the residual $1.2 million which was recorded in additional paid-in capital to reflect the relative fair value of the warrants and the conversion option embedded in the new Novartis Loan Note. No extinguishment gain or loss was recognized. The Company recognized interest expense of $0.3 million and $0.6 million in relation to the Novartis Loan Note in the unaudited condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2024, respectively and $0.2 million and $0.5 million in the three and six months ended June 30, 2023 respectively. The effective interest rate applied to the liability portion of the Novartis Loan Note in the three and six months ended June 30, 2024 was 27.8% (2023: 27.8% after the amendments and 37.4% before).

As of June 30, 2024 and December 31, 2023, the net carrying amount of the liability component of the convertible debt instrument was $4.9 million and $4.4 million, respectively and the fair value was $3.3 million and $3.1 million, respectively.

Private Placement Loan Notes

The Private Placement Loan Notes were issued in 2020 as part of a $70.0 million private placement transaction which also included the issuance of ordinary shares and warrants. The Private Placement Loan Notes were originally convertible at a fixed price of £0.174 per ordinary share, bore interest at a rate of 6% per annum and had a maturity date of June 3, 2023.

In May 2023, the maturity date of the Private Placement Loan Notes was extended to August 3, 2023, with all other terms remaining unchanged. This extension was a modification and the carrying value of the liability component was adjusted to the present value of the modified cash flows discounted at the original effective interest rate, net of identifiable transaction costs. The carrying value was also reduced by $0.6 million with a corresponding adjustment to additional paid-in capital to reflect the increase in the fair value of the embedded conversion option.

In 2023, the Company received conversion notices and subsequently issued and allotted 17,774,895 ordinary shares in the three months ended June 30, 2023 and 9,645,200 ordinary shares in the three months ended September 30, 2023, both at a price of £0.174 per share on non-cash conversion of Private Placement Loan Notes with an aggregate principal amount of $4.6 million. In 2023, the Company also paid $3.2 million to fully settle the outstanding principal and accrued interest balance.

The Company recognized $0.7 million and $1.1 million of interest expense in the three and six months ended June 30, 2023 respectively. The effective interest rate applied to the liability portion of the Private Placement Loan Notes in 2023 after the amendments was 27.1% while the effective interest rate applied in 2023 before the amendments was 25.1%.