What is confirmed, on the record, is the agreement itself: on October 8, 2023, Bristol Myers Squibb and Mirati Therapeutics announced a definitive merger agreement under which the larger company will pay $58.00 per share in cash, an equity value the companies put at $4.8 billion, with a further contingent right worth $12.00 per share bringing the potential consideration up to $5.8 billion. What remains pending, the statement is careful to say, is everything else: the deal still requires Mirati stockholder approval and regulatory clearances, with closing anticipated in the first half of 2024. Both boards approved the terms unanimously. For a measure of the strategic premium: the cash price represents a 52% premium to the 30-day traded average as of the unaffected October 4 close.
The center of the bet is a lung cancer drug. KRAZATI, or adagrasib, holds accelerated U.S. approval for certain patients with advanced forms of non-small cell lung cancer whose tumors harbor a KRAS G12C mutation, after at least one prior systemic treatment; the mutation accounts for roughly 14% of that disease. The statement credits the medicine with a long half-life, early-stage trials that pair it with a PD-1 inhibitor in the first-line setting, penetration into the central nervous system with responses in patients with brain metastases, and data in colorectal and pancreatic cancer settings.
The pipeline behind it is the rest of the case. MRTX1719, a potential first-in-class PRMT5 inhibitor aimed at MTAP-deleted tumors, targets a biology present in about 10% of all cancers, with a Phase 2 start expected in the first half of 2024. Behind it sit MRTX1133, directed at the KRAS G12D mutation implicated in over 30% of pancreatic cancers, and MRTX0902, a SOS1 inhibitor in Phase 1 development.
The account indicates the financial mechanics plainly. The contingent right pays out only if the FDA accepts a new drug application for MRTX1719 within seven years of closing; the purchase dilutes Bristol Myers Squibb’s earnings by about $0.35 per share across the first 12 months after close; financing combines cash and debt. Chief Executive Giovanni Caforio framed the logic: “We are excited to add these assets to our portfolio and to accelerate their development as we seek to deliver more treatments for cancer patients,” adding that “the Mirati transaction is aligned with our business development goals.”
Two claims deserve separation. The companies say the science is strong; the record so far shows an agreement, not a closed deal, and a contingent payout that may never materialize. Mirati founder Charles Baum defended the sale in the plainest terms: “We believe that this transaction is the best way to benefit patients and maximize value for shareholders.” That is a judgment, not a guarantee. The decisive dates, on the timeline, are the stockholder vote and the regulatory decisions to come.
Sources
- Bristol Myers Squibb Completes Acquisition of Mirati to Bolster Oncology Pipeline | PharmExec
- Bristol Myers Squibb concludes Mirati acquisition for $5.8bn
- Bristol Myers Squibb Strengthens and Diversifies Oncology Portfolio With Acquisition of Mirati Therapeutics (BMS official press release)
