MPM BIOVENTURES 2018, L.P. purchased 12.2% of their position (1.11M shares) of AKTIS ONCOLOGY, INC. on the open market

Open‑market purchase worth $20.03M — a moderate purchase. The strongest form of insider conviction signal.

P · 1 purchase

MPM BIOVENTURES 2018, L.P.

Filed: 1/14/2026ACC: 0001231919-26-000057

InsiderMPM BIOVENTURES 2018, L.P.CIK 1729505

→

IssuerAKTIS ONCOLOGY, INC.CIK 2035832

10% Owner

Since Jan 2026

-23.58M

Net shares

Net seller

$20.03M

Total acquired

Open market trades

1B · 0S

Total transactions

9.92M acquired · 33.50M disposed

Non-Derivative Transactions4

Common Stock

Indirect

C · Conversion

+1.31M

Price / share

—

Trade value

—

% of position

384.6%

1/12/2026

341.71K→1.66M

Common Stock

Indirect

C · Conversion

+5.91M

Price / share

—

Trade value

—

% of position

357.1%

1/12/2026

1.66M→7.57M

Common Stock

Indirect

C · Conversion

+1.58M

Price / share

—

Trade value

—

% of position

20.8%

1/12/2026

7.57M→9.15M

Common Stock

Indirect

P · Purchase

+1.11M

Price / share

$18.00

Trade value

$20.03M

% of position

12.2%

1/12/2026

9.15M→10.26M

Total

Net shares

+9.92M

Net value

$20.03M

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Common Stock Indirect	1/12/2026	C · Conversion	+1.31M	—	—	384.6%	341.71K	1.66M
Common Stock Indirect	1/12/2026	C · Conversion	+5.91M	—	—	357.1%	1.66M	7.57M
Common Stock Indirect	1/12/2026	C · Conversion	+1.58M	—	—	20.8%	7.57M	9.15M
Common Stock Indirect	1/12/2026	P · Purchase	+1.11M	$18.00	$20.03M	12.2%	9.15M	10.26M
Total			+9.92M		$20.03M

Derivative Transactions3

Series Seed Redeemable Convertible Preferred Stock

Indirect

C · Conversion

Converts to

Common Stock

1.31M shares

−5M

Strike price

Held after

0.00

Exercisable

—

1/12/2026

Series A Redeemable Convertible Preferred Stock

Indirect

C · Conversion

Converts to

Common Stock

5.91M shares

−22.50M

Strike price

Held after

0.00

Exercisable

—

1/12/2026

Series B Redeemable Convertible Preferred Stock

Indirect

C · Conversion

Converts to

Common Stock

1.58M shares

−6M

Strike price

Held after

0.00

Exercisable

—

1/12/2026

Security	Converts To	Date	Type	Shares	Exercisable
Series Seed Redeemable Convertible Preferred Stock Indirect	Common Stock1.31M shares	1/12/2026	C · Conversion	−5M	—
Series A Redeemable Convertible Preferred Stock Indirect	Common Stock5.91M shares	1/12/2026	C · Conversion	−22.50M	—
Series B Redeemable Convertible Preferred Stock Indirect	Common Stock1.58M shares	1/12/2026	C · Conversion	−6M	—