Shares of biotech Summit Therapeutics (SMMT -3.61%) skyrocketed 583.7% in 2024, according to data from S&P Global Market Intelligence.

Summit was an early-stage biotechnology stock heading into the year, but the company graduated to a higher class in 2024 following promising trial results for Ivonescimab, its monoclonal antibody drug for lung cancer.

Ivonescimab to displace Keytruda?

Summit's stock generated all of its gains in two big chunks in 2024, with one in May and another in September, with each move following the disclosure of different phase 3 trial data.

In May, Summit released the data from its HARMONi-A phase 3 trial in partnership with Akeso (AKES.F -1.95%). The trial combined Ivonescimab with chemotherapy in patients with (EGFR)-mutated, locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC), after the disease had progressed following EGFR-TKI treatment. That trial produced a 54% reduction in disease progression or death compared with the placebo group.

Then in September, Summit released results of another phase 3 trial, HARMONi-2, also in conjunction with Akeso. In that trial, Ivonescimab went up against Keytruda, which had been the current standard of care for monoclonal antibody treatments in NSCLC patients whose tumors had positive PD-L1 expression.

In that trial, Ivonescimab bested Keytruda significantly, with a progression-free survival (PFS) rate of 11.14 months versus the 5.82 months for Keytruda. While there were slightly more treatment-related adverse side effects in Ivonescimab, the side effects were relatively close to Keytruda's and within a "manageable safety profile."

Finally, in October, the Food and Drug Administration (FDA) approved Ivonescimab for "fast track" designation, which means a full approval may come sooner than later for this important therapy.

Blockbuster drug in the making?

Ivonescimab has the makings of a potential blockbuster drug, given that the end market for PDL-1 lung cancer drugs is roughly $50 billion, according to analysts. So, it's no wonder Summit's stock more than sextupled during the year.

These full-year gains came in spite of Summit's stock pulling back well off its 52-week high of $33.89 to end the year at $19.51 per share. The stock has continued to sink in the new year, reaching $16.65 as of this writing.

But in early 2025, Wall Street remains bullish, with Truist analyst Asthika Goonewardene recently giving the stock a buy rating and $35 price target, predicting Ivonescimab might become available in the U.S. and Europe in early 2026. Goonewardene thinks Ivonescimab could generate annual sales in the "double-digit billions," which may therefore make Summit an attractive acquisition target for a larger pharmaceutical company.

So despite the massive 2024 gains, there may still be value left in this biotech stock yet.