Loxo Oncology’s shares shoot up on early data slated for ASCO presentation

Loxo’s data highlight growing industry interest in so-called “basket” trials and drugs that targeted to genetic markers instead of tumor types.

Shares of Loxo Oncology rose 20 percent by the time markets closed Thursday following the release of an abstract from an early-stage clinical trial the company is expected to present at next month’s annual meeting of the American Society of Clinical Oncology.

Abstracts for the ASCO meeting went up Wednesday night, including the one for Stamford, Connecticut-based Loxo’s early-stage clinical trial of LOXO-292. The Phase I data on 32 patients showed 22 responding to treatment, yielding a 69 percent overall response rate, though 11 of those patients’ responses are not yet confirmed. Loxo closed at $167.53 per share Thursday, from Wednesday’s closing share price of $139.50.

The company is developing LOXO-292 in patients whose cancers exhibit alterations of the gene RET, and is enrolling participants in its Phase I trial based on their expression of the gene rather than a specific tumor type. The data from the ASCO abstract include patients with non-small cell lung cancer, papillary thyroid cancer (PTC), medullary thyroid cancer (MTC) and pancreatic cancer, though the study’s entry in the registry states it enrolls patients with any solid tumor exhibiting a RET alteration. RET mutations occur in 60 percent of MTC, along with 10-20 percent of PTC and 1-2 percent of NSCLC, according to Loxo.

The data posted Wednesday night – for which the company plans to provide an update in an oral presentation at the ASCO meeting – follow data presented at last year’s ASCO meeting on the company’s lead drug candidate, LOXO-101. LOXO-101, whose generic name is larotrectinib, targets fusions of the TRK gene and is currently in a Phase II “basket” study of 151 patients that also enrolls patients based on the presence of the biomarker rather than the tumor type.

The data last year showed confirmed responses among 76 percent of adults and children receiving the drug. Loxo announced in March that it had completed a rolling submission of data for Food and Drug Administration approval of larotrectinib, with plans to file for European Medicines Agency approval this year. In November, Loxo announced a global development and commercialization deal with German drugmaker Bayer worth up to $1.55 billion for larotrectinib and Loxo’s second-generation TRK inhibitor, LOXO-195.

A close competitor to Loxo is Blueprint Medicines, which is developing the RET inhibitor BLU-667, also in MTC, PTC and NSCLC and other RET-altered cancers. Among 40 patients evaluable for efficacy, 45 percent responded to treatment with the drug, according to data presented at the American Association for Cancer Research’s annual meeting on April 15. Blueprint shares were down 10.7 percent at noon Thursday from their $86.38 Wednesday closing price.

Another competitor is Ignyta, which is developing a TRK inhibitor called entrectinib, or RXDX-101. However, unlike larotrectinib, entrectinib also inhibits other kinases, including ROS and ALK. Ignyta will present early clinical data for the drug in children and adolescents at the ASCO meeting. Swiss drugmaker Roche announced in December it would buy Ignyta for $1.7 billion, completing the deal in February.

The data from Loxo, Blueprint and Ignyta highlight a growing industry interest in basket studies and drug treatment that relies on genetic drivers of cancers rather than being tied to tumor types. Last May, Merck & Co.’s immune checkpoint inhibitor Keytruda received FDA approval for use in any solid tumor that has spread or can’t be removed through surgery and exhibits a genetic marker called microsatellite instability-high or mismatch repair deficiency, also known as MSI-H and dMMR. Keytruda’s most direct competitor, Bristol-Myers Squibb’s Opdivo – both drugs work by inhibiting a “brake” on the immune system called PD-1 – is only approved for MSI-H and dMMR colorectal cancer.

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