Adaptimmune Sees Positive Early Results in Cancer Treatment

Shares of Adaptimmune Ltd. surged late Thursday after the company reported it saw three partial responses in three of the four myxoid/ round cell liposarcoma (MRCLS) patients the company dosed with its NY-ESO SPEAR (Specific Peptide Enhanced Affinity Receptor) T-cells.

The news sent company stock up more than 20 percent to $12.41 per share. Since that spike, shares have fallen back some to $10.74 as of 10:51 a.m.

Those positive results are also good news for GlaxoSmithKline, which licensed the NY-ESO SPEAR T-cell therapy program last fall. The two companies initiated their collaboration in 2014 and last year the pharma giant exercised its option to exclusively license Adaptimmune’s NY-ESO SPEAR T-cell therapy program. The transition has not yet been completed.

MRCLS is a type of liposarcoma that is characterized by the proliferation of adipocyte (fat cell) precursors called lipoblasts that have undergone differentiation arrest. MRCLS represents about 30 to 35 percent of liposarcomas and 5 to 10 percent of all adult soft tissue sarcomas. It is estimated that there are approximately 2000 patients in the United States and Europe with MRCLS each year.

Rafael Amado, Adaptimmune’s chief medical officer, said the company is encouraged by the initial responses in the first patients dosed. He said the news validates the potential for its platform to treat a broad range of tumors, including those known to be unresponsive to current immunotherapy treatments.

“Although MRCLS is a soft tissue sarcoma which commonly expresses NY-ESO, there are fundamental differences in its clinical course, natural history, molecular signature, and responsiveness to standard treatments that make it distinct from synovial sarcoma. As we expect data from our other trials with our wholly owned assets throughout 2018, these results in a second solid tumor strengthen our conviction that our pipeline of unique TCRs will be capable of addressing multiple solid tumors,” Amado said in a statement.

So far Adaptimmune has dosed four patients with its treatment. Of the three partial responses the company said two have been confirmed and one has yet to be confirmed. The other patient was classified as having stable disease. Adaptimmune said the doses were well-tolerated. However, the company said it did see cases of cytokine release syndrome (CRS), a systemic inflammatory response that has been a persistent concern in other CAR-T and cell therapy trials. The CRS cases Adaptimmune patients encountered were managed following standard treatment guidelines, the company said.

Two years ago the U.S. Food and Drug Administration placed a partial clinical hold on the NY-ESO SPEAR T-cell study for MRCLS. The hold was lifted after Adaptimmune revised the trial protocol.

In addition to its NY-ESO SPEAR T-cell study, Adaptimmune is using SPEAR T-cells in two clinical trials targeting MAGE-A10, one in non-small cell lung cancer (NSCLC), and a triple tumor study in bladder, melanoma, and head & neck cancers. Both studies are dose escalation trials that evaluate three doses of transduced SPEAR T-cells, administered after a lymphodepleting chemotherapy regimen. In addition to the MAGE-A10 trial, Adaptimmune is also targeting MAGE-A4. The newly manufactured SPEAR T-cell at the Philadelphia site will be used in a multiple tumor study in bladder, melanoma, head & neck, ovarian, non-small cell lung, esophageal, and gastric cancers.