Funding round
Kailera Therapeutics Series B
Kailera Therapeutics, which works in biopharmaceutical research and development in Waltham, raised $600M in a Series B round announced on 14 Oct 2025, led by Bain Capital Private Equity. 14 firms took part, 4 of them already investors. It is Kailera Therapeutics' second venture round on record; the one before was a Series A in Oct 2024.
$600M
Amount raised
Not disclosed
Post-money valuation
14
Investors
1 lead
Valuation
What this round says about the price
Kailera Therapeutics did not disclose a valuation in this round; its last disclosed one was $1.50B at the Series A (Oct 2024). It came 12 months after Kailera Therapeutics' Series A. It is 60% of the $1.00B Kailera Therapeutics has raised in the venture rounds on record. No later venture round is on record for Kailera Therapeutics.
Kailera Therapeutics' funding rounds
Kailera Therapeutics has 2 venture rounds on record. This one is highlighted.
- Series A 1 Oct 2024, led by Atlas Venture, Bain Capital Life Sciences and RTW Investments $400M$1.50B post-money
- Series B this round 14 Oct 2025, led by Bain Capital Private Equity $600M
Investors
Who put money in
Bain Capital Private Equity led the round with 13 other firms. Atlas Venture, Bain Capital Life Sciences, RTW Investments and Sirona Capital had backed Kailera Therapeutics before.
Lead investor
- backs 8 venture-backed companies new investor
Also in the round
- Adage Capital Management LP new investor
- Canada Pension Plan Investment Board new investor
- Invus backs 83 venture-backed companies new investor
- Janus Henderson Investors new investor
- Perseverance Capital new investor
- Qatar Investment Authority backs 71 venture-backed companies new investor
- backs 2 venture-backed companies new investor
- backs 26 venture-backed companies new investor
- T. Rowe Price Associates, Inc. new investor
- backs 43 venture-backed companies existing investor
- Bain Capital Life Sciences existing investor
- backs 17 venture-backed companies existing investor
- Sirona Capital existing investor
Joined the board: Andrew Kaplan (Bain Capital Private Equity).
Use of proceeds
What the money is for
According to the announcement, the money goes to product development, scaling operations and working capital.
- Product development
- Scaling operations
- Working capital
Comparable rounds
How it compares
54 Series B rounds in Pharmaceutical Products within a year either side disclosed an amount; the median was $41M, and this round was 14 times the median. The closest in time, other companies' Series B rounds in Pharmaceutical Products:
| Company | Announced | Amount | Post-money | Led by |
|---|---|---|---|---|
| Pharmaceutical Products | 24 Oct 2025 | $42M | not disclosed | LYFE Capital and 高瓴创投 |
| Pharmaceutical Products | 21 Oct 2025 | $36M | not disclosed | Biotech Specialist Funds |
| Pharmaceutical Products | 30 Oct 2025 | $25M | not disclosed | Atomic and Foresite Capital |
| Pharmaceutical Products | 22 Oct 2025 | $22M | not disclosed | Brandon Capital and Uniseed |
| Pharmaceutical Products | 22 Oct 2025 | $17M | not disclosed | Adjuvant Capital and RA Capital |
| Pharmaceutical Products | 24 Sep 2025 | $95M | not disclosed | RA Capital and Forbion |
| Pharmaceutical Products | 2 Sep 2025 | $80M | not disclosed | New Enterprise Associates and SR One |
| Pharmaceutical Products | 8 Sep 2025 | $67M | not disclosed | SV Health Investors |
Sources
Where this comes from
Reported by 4 sources.
Questions
Frequently asked
How much did Kailera Therapeutics raise in its Series B round?
Kailera Therapeutics raised $600M in its Series B round, announced in Oct 2025.
Who led Kailera Therapeutics' Series B round?
Bain Capital Private Equity led it, with Adage Capital Management LP, Canada Pension Plan Investment Board, Invus, Janus Henderson Investors and Perseverance Capital and 8 more.
What was Kailera Therapeutics' valuation at the Series B round?
It was not disclosed; its last disclosed one was $1.50B at the Series A (Oct 2024).
How does it compare with other Series B rounds in Pharmaceutical Products?
54 Series B rounds in Pharmaceutical Products within a year either side disclosed an amount; the median was $41M, and this round was 14 times the median.