MacroGenics Inc (NASDAQ:MGNX) released interim data from the TAMARACK Phase 2 study of vobramitamab duocarmazine (vobra duo).
TAMARACK is being conducted in previously treated patients with metastatic castration-resistant prostate cancer (mCRPC).
MacroGenics reported five deaths (fatal outcome) during the trial. It also reported over 50% rate of grade 3, or worse, adverse events in both dose cohorts (2 mg/kg and 2.7 mg/kg every four weeks).
- B Riley maintains the Buy rating on MacroGenics with a price target of $25.
- BMO Capital Markets downgraded MacroGenics from Outperform to Market Perform with a price target of $8 from $24 on lower conviction on the prostate cancer program.
- JMP writes while maintaining the Outperform rating.
B Riley notes that an unexpected increase in treatment interruptions and discontinuations from week 12 to week 24 could imply a lower likelihood of success in a relatively crowded mCRPC landscape.
The firm notes that >Grade 1 Palmar-plantar erythrodysaesthesia (PPE) cases at wk-24 were just 4.4%/10% in the 2/2.7 mg/kg arms vs. 31% reported in the 3 mg/kg arm, representing a significant improvement in what was the most concerning side-effect.
Strong clinical activity was observed even in the 2 mg/ kg arm.
BMO Capital Markets' analyst previously discussed the competitive landscape in metastatic castration-resistant prostate cancer (mCRPC) and the standards anticipated MacroGenics needed to meet in the recently revealed TAMARACK results. However, the effectiveness and safety updates from the study failed to meet expectations.
JMP Securities writes, "We were surprised by five newly reported deaths in the data, which will likely lead to volatility."
Based on Novartis AG's (NYSE:NVS) PSMAfore and Exelixis Inc's (NASDAQ:EXEL) CONTACT-02, the analyst points out that the death rate in the mCRPC setting is ~2-12%, and the recorded deaths in TAMARACK (2.8% of patients) fall within this range.
JMP says ORR is the highlight of the update. There is a large discrepancy between confirmed and unconfirmed numbers, but 18-25% (confirmed) and 24-44% (total) compare well.
Cabo+Atezo (CONTACT-02 showed a 14% ORR), Pluvicto has a 51% ORR, and emerging bispecifics have an ORR of 41-56%.
"Overall, given several new compounds vying for a place in mCRPC, we need to wait for the 2H24 data to form a full picture of the opportunity," JMP writes.
Price Action: MGNX shares are down 77.7% at $3.27 at last check Friday.
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