A KalVista Pharmaceuticals eye drug at the center of a research collaboration with Merck has failed a mid-stage clinical trial.
KalVista (NASDAQ: KALV) developed its drug, KVD001, to treat diabetic macular edema (DME), a complication of diabetes that can lead to blindness. On Monday, Cambridge, MA-based KalVista said patients treated with the drug, given as a monthly injection to the eye, did not show enough vision improvement after 16 weeks to distance the experimental therapy from a sham treatment.
Merck signed on as a KalVista partner in 2017 after the biotech reported encouraging Phase 1 data. Under the agreement, Merck gained an option to license KVD001 after the completion of a Phase 2 clinical trial financed by the Kenilworth, NJ-based pharmaceutical giant. Merck paid its partner $37 million up front, and agreed to another $715 million in milestone payments pegged to the progress of the KVD001 and other unspecified KalVista drugs.
DME is caused by a buildup of fluid in the macula, which is the center of the retina. This buildup causes the macula to swell and thicken, distorting vision. KalVista hoped its drug could provide another treatment option for patients who don’t respond to a class of drugs called vascular endothelial growth factor (VEGF) inhibitors.
The KalVista drug was developed to block plasma kallikrein, an enzyme that plays a role in inflammation. Though this approach did not succeed in the DME clinical trial, KalVista might have better luck targeting that enzyme to treat another disorder. The company is developing KVD900 to treat the rare disease hereditary angioedema (HAE). The inherited disorder leads to swelling attacks affecting the limbs, face, airway, and intestines. A Phase 2 study is expected to report data in 2020.
In a note to investors, SVB Leerink’s Dae Gon Ha described KVD900 as KalVista’s “more prized asset.” He added that unlike in DME, blocking plasma kallikrein to address HAE is a less risky bet. The enzyme’s role in HAE has been documented in numerous studies, and injectable plasma kallikrein inhibitors for HAE have already reached the market.
But KalVista’s experimental HAE pill has looming competition. An oral plasma kallikrein inhibitor that BioCryst Pharmaceuticals (NASDAQ: BCRX) developed to prevent and treat HAE attacks is now being prepared for FDA review. In its third quarter financial report, the Durham, NC-based biotech said it expects to file its application with the regulator in the fourth quarter of this year.