First-in-class immune-stimulating antibody conjugate BDC-4182 Phase 1/2 study ongoing, initial clinical data expected to be released with Bolt's 3Q 2026 results
Cash balance of $18.1 million as of June 30, 2026 anticipated to fund operations into 1Q 2027

REDWOOD CITY, Calif., Aug. 11, 2026 (GLOBE NEWSWIRE) -- Bolt Biotherapeutics (Nasdaq: BOLT), a clinical-stage biopharmaceutical company developing novel immunotherapies for the treatment of cancer, today reported financial results for the second quarter ended June 30, 2026, and provided a business update.

“In the second quarter, we continued to make meaningful progress in the ongoing BDC-4182 Phase 1/2 study in patients with gastric and gastroesophageal cancer. We are currently treating patients in Cohort 4. To date, BDC-4182 has been well tolerated, and we are seeing activity consistent with our immune-stimulating mechanism,” said Willie Quinn, President and Chief Executive Officer. “We expect to report initial clinical data from BDC-4182 with our third quarter 2026 results.”

Recent Highlights and Anticipated Milestones

Initial clinical data from BDC-4182 Phase 1/2 study for patients with gastric and gastroesophageal cancer expected with third quarter 2026 results. BDC-4182 is a next-generation Boltbody™ ISAC targeting claudin 18.2, a clinically validated target with expression in gastric cancer, gastroesophageal junction cancer, pancreatic cancer, and other tumor types. In preclinical models, including cancer models with low claudin 18.2 expression, BDC-4182 demonstrated significant anti-tumor activity, induced immunological memory, and outperformed cytotoxic ADCs. Bolt has implemented step-up dosing, which has been successfully used commercially for T-cell engagers, as a strategy to get to higher doses safely. The clinical trial in gastric and gastroesophageal cancers is progressing well with ongoing treatment of patients in Cohort 4 at the 4.0 mg/kg dose level.
Cash, cash equivalents, and marketable securities were $18.1 million as of June 30, 2026. Cash on hand is expected to fund operations into the quarter 2027.

Second Quarter 2026 Financial Results

Collaboration Revenue – Total collaboration revenue was $5,000 for the quarter ended June 30, 2026, compared to $1.8 million for the same quarter in 2025. Revenue in the comparative periods was generated from services performed under the R&D collaborations as we fulfill our performance obligations.
Research and Development (R&D) Expenses – R&D expenses were $5.1 million for the quarter ended June 30, 2026, compared to $7.5 million for the same quarter in 2025. The decrease between the comparable periods was mainly due to a decrease in salary and related expenses primarily as a result of our restructuring and overall lower research and development activities.
General and Administrative (G&A) Expenses – G&A expenses were $2.4 million for the quarter ended June 30, 2026, compared to $3.5 million for the same quarter in 2025. The decrease between the comparable periods was mainly due to a decrease in salary and related expenses primarily as a result of our restructuring as well as lower consulting expenses.
Loss from Operations – Loss from operations was $8.4 million for the quarter ended June 30, 2026, compared to $9.2 million for the same quarter in 2025.

About the Boltbody™ Immune-Stimulating Antibody Conjugate (ISAC) Platform
Bolt Biotherapeutics’ Boltbody ISAC platform harnesses the precision of antibodies with the power of the innate and adaptive immune system to generate a productive anti-cancer response. Each Boltbody ISAC candidate comprises a tumor-targeting antibody, a non-cleavable linker, and a proprietary immune stimulant. The antibody is designed to target one or more markers on the surface of a tumor cell and the immune stimulant is designed to recruit and activate myeloid cells. Activated myeloid cells initiate a positive feedback loop by releasing cytokines and chemokines, chemical signals that attract other immune cells and lower the activation threshold for an immune response. This increases the population of activated immune system cells in the tumor microenvironment and promotes a robust immune response with the goal of generating durable therapeutic responses for patients with cancer.

About Bolt Biotherapeutics, Inc.
Bolt Biotherapeutics is a clinical-stage biopharmaceutical company developing novel immunotherapies for the treatment of cancer. Bolt Biotherapeutics’ pipeline reflects the Company’s expertise in myeloid biology and cancer drug development. The Company’s lead program is BDC-4182, a next-generation Boltbody™ Immune-Stimulating Antibody Conjugate (ISAC) clinical candidate targeting claudin 18.2. BDC-4182 is currently in a Phase 1/2 trial that includes patients with gastric and gastroesophageal cancer. The Company has strategic collaborations with Genmab and Toray built around the Company’s Boltbody™ ISAC platform technology. The rest of the Company’s pipeline is currently on hold, including BDC-3042, a Dectin-2 agonist that completed a first-in-human Phase 1 dose escalation trial, as well as its preclinical ISAC programs targeting CEA and PD-L1. For more information, please visit https://www.boltbio.com/.

Forward-Looking Statements
This press release contains forward-looking statements about us and our industry that involve substantial risks and uncertainties and are based on our beliefs and assumptions and on information currently available to us. All statements other than statements of historical facts contained in this press release, including statements regarding our ability to partner our CEA ISAC and PD-L1 ISAC, the advancement and success of our BDC-4182 clinical trials, the timing of initial data from our Phase 1 dose-escalation study of BDC-4182, the timing of our ISAC programs, the anti-tumor potency, safety and tolerability, and characteristics of our product candidates, the initiation of future clinical trials, the potential value of collaborations, and the expected duration of our cash runway and ability to fund key milestones into first quarter 2027, are forward-looking statements. In some cases, you can identify forward-looking statements because they contain words such as “anticipate,” “believe,” “could,” “estimate,” “expect,” “intend,” “may,” “on track,” “plan,” “potential,” “predict,” “project,” “should,” “will,” or “would,” or the negative of these words or other similar terms or expressions. Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance, or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Forward-looking statements represent our current beliefs, estimates and assumptions only as of the date of this press release and information contained in this press release should not be relied upon as representing our estimates as of any subsequent date. These statements, and related risks, uncertainties, factors and assumptions, include, but are not limited to: the potential product candidates that we develop may not progress through clinical development or receive required regulatory approvals within expected timelines or at all; clinical trials may not confirm any safety, potency or other product characteristics described or assumed in this press release; such product candidates may not be beneficial to patients or become commercialized; and our ability to maintain our current collaborations and establish further collaborations. These risks are not exhaustive. Except as required by law, we assume no obligation to update these forward-looking statements, or to update the reasons actual results could differ materially from those anticipated in the forward-looking statements, even if new information becomes available in the future. Further information on factors that could cause actual results to differ materially from the results anticipated by our forward-looking statements is included in the reports we have filed or will file with the Securities and Exchange Commission, including our Annual Report on Form 10-K and Quarterly Reports on Form 10-Q. These filings, when available, are available on the investor relations section of our website at investors.boltbio.com and on the SEC’s website at www.sec.gov.

Investor Relations and Media Contact:
Matthew DeYoung
Argot Partners
(212) 600-1902
boltbio@argotpartners.com

BOLT BIOTHERAPEUTICS, INC.
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
(Unaudited, in thousands, except share and per share amounts)

	Three Months Ended June 30,						Six Months Ended June 30,
	2026			2025			2026			2025
Collaboration revenue	$	5		$	1,804		$	31		$	3,026
Operating expenses:
Research and development		5,149			7,498			9,978			17,010
General and administrative		2,422			3,516			5,220			7,341
Impairment charges		808			—			808			—
Total operating expense		8,379			11,014			16,006			24,351
Loss from operations		(8,374	)		(9,210	)		(15,975	)		(21,325	)
Other income (expense), net:
Interest income, net		178			599			454			1,652
Other income, net		476			50			557			72
Total other income (expense), net		654			649			1,011			1,724
Net loss		(7,720	)		(8,561	)		(14,964	)		(19,601	)
Net unrealized loss on marketable securities		(33	)		(46	)		(23	)		(103	)
Comprehensive loss	$	(7,753	)	$	(8,607	)	$	(14,987	)	$	(19,704	)
Net loss per share, basic and diluted	$	(4.57	)	$	(4.46	)	$	(8.88	)	$	(10.22	)
Weighted-average shares outstanding, basic and diluted		1,690,529			1,917,629			1,685,514			1,917,288

BOLT BIOTHERAPEUTICS, INC.
CONDENSED CONSOLIDATED BALANCE SHEETS
(Unaudited, in thousands)

	June 30,			December 31,
	2026			2025
*Assets*
Current assets:
Cash and cash equivalents	$	12,860		$	11,703
Short-term investments		4,738			15,802
Restricted cash		200			200
Prepaid expenses and other current assets		2,766			2,555
Total current assets		20,564			30,260
Property and equipment, net		571			1,245
Operating lease right-of-use assets		17,075			19,230
Restricted cash, non-current		1,538			1,538
Long-term investments		509			4,337
Other assets		87			138
Total assets	$	40,344		$	56,748
*Liabilities and stockholders' equity*
Current liabilities:
Accounts payable	$	868		$	1,443
Accrued expenses and other current liabilities		3,089			3,717
Deferred revenue		819			449
Operating lease liabilities		3,091			2,826
Total current liabilities		7,867			8,435
Operating lease liabilities, net of current portion		18,533			20,132
Deferred revenue, non-current		1,172			1,544
Other long-term liabilities		132			132
Total liabilities		27,704			30,243
Commitments and contingencies
*Stockholders' equity:*
Common stock		—			—
Additional paid-in capital		488,427			487,305
Accumulated other comprehensive loss		(44	)		(21	)
Accumulated deficit		(475,743	)		(460,779	)
Total stockholders' equity		12,640			26,505
Total liabilities and stockholders' equity	$	40,344		$	56,748

BOLT BIOTHERAPEUTICS, INC.
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
(Unaudited, in thousands)

	Six Months Ended June 30,
	2026			2025
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$	(14,964	)	$	(19,601	)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization		374			746
Stock-based compensation expense		1,097			1,334
Accretion of discount on marketable securities		(122	)		(379	)
Gain on sale of property and equipment		(404	)		(288	)
Asset impairment		808			—
Non-cash lease expense		1,347			1,239
Changes in operating assets and liabilities:
Prepaid expenses and other assets		(160	)		(236	)
Accounts payable and accrued expenses		(1,203	)		(3,351	)
Operating lease liabilities		(1,334	)		(1,026	)
Deferred revenue		(2	)		(1,533	)
Other long-term liabilities		—			133
Net cash used in operating activities		(14,563	)		(22,962	)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment		(13	)		—
Proceeds from sales of property and equipment		717			963
Purchases of marketable securities		(1,230	)		(15,457	)
Maturities of marketable securities		16,221			39,838
Net cash provided by investing activities		15,695			25,344
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock		25			14
Net cash provided by financing activities		25			14
NET INCREASE (DECREASE) IN CASH		1,157			2,396
Cash, cash equivalents and restricted cash at beginning of year		13,441			8,970
Cash, cash equivalents and restricted cash at end of period	$	14,598		$	11,366
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	$	12,860		$	9,601
Restricted cash		1,738			1,765
Total cash, cash equivalents and restricted cash	$	14,598		$	11,366

Bolt Biotherapeutics Reports Second Quarter 2026 Financial Results and Provides Business Update