An Israeli pharmaceutical under development boosts the ability of the body’s natural cancer-fighting cells to overcome malignant invaders.
By David Halevi
Cancer is an extremely wily opponent, using some pretty underhanded tactics to attack the human body and spread its poisonous cells for as long as it can. In order to fight cancer, the body needs to be just as wily to "outsmart" cancerous cells, somehow preventing them from spreading.
While the notion of "fooling" cancer seems a stretch, it’s exactly what Yavne-based CureTech is doing as it develops a novel treatment called CT-011. Preliminary results of a clinical trial involving patients with a particularly aggressive form of lymphoma show CT-011 has a promising future.
Normally, special defense antibodies known as cytotoxic T-cells are activated to battle the foreign invaders, aka cancer cells. The T-cells fight the tumor cells head-to-head in an attempt to defeat them – but recent scientific evidence suggests that many types of cancer can "outwit" the T-cells, rendering them ineffective, says CureTech CEO Dr. Michael Schickler.
"The cancerous cells manage to pull off this trick by utilizing an existing natural ‘break’ of the body’s immune system, producing high levels of a protein called PD-L1, which interacts with a receptor called PD-1, a feature of T-cells," he explains. This interaction essentially results in the issuance of a "self-destruct" signal to the T-cells. Once the body’s best hope of holding off the invasion is neutralized, the cancer cells have a free hand to grow and wreak havoc on the body.
That’s where CT-011 comes in. This advanced antibody runs interference with a cancer’s ability to fool T-cells. "CT-011 links with PD-1 on activated T-cells and blocks its interaction with PD-L1 on the tumor cells, thus preventing the formation of the death signals in the T-cells," Schickler explains. T-cells can then continue their work of fighting the cancer, and the patient has a much better chance of surviving.
In fact, the body learns a few tricks of its own when CT-011 is introduced, based on evidence from CureTech’s studies. "It appears that CT-011 may facilitate the formation of specific anti-tumor memory cells that can become active once cancer cells are detected by the immune system," Schickler says. These unique blood cells help fight off future incidents of cancer.
Saving lives even at testing stage
CureTech, which is privately held, is a portfolio company of Israeli pharmaceutical giant Teva Pharmaceutical Industries. CureTech began working with Teva in 2006, and the company increased its investment in CureTech in 2008 and again in 2011.
CureTech was established in 2001 by Schickler, who had been involved in the biopharmaceutical business for nearly two decades. Today, the company has 20 employees, nearly all of them researchers working on advancing the capabilities of CT-011.
In 2008, CureTech began several Phase II trials on the effectiveness of CT-011, and recently announced preliminary successful results in patients with diffuse large B-cell lymphoma (DLCBL) following stem cell transplantation. After being treated with CT-011, the deterioration of patients with DLBCL (an aggressive type of non-Hodgkin’s lymphoma affecting about 35 percent of lymphoma patients) was halted in 70 percent of participants of the 72-patient study, compared with 57% in a control group.
Even more strikingly, says Schickler, 84% of patients were alive at the end of the follow-up period, compared with 62% in the historical control. Altogether, more than 400 patients have participated in seven studies with CT-011 for different cancers, including colon cancer, multiple myeloma, acute leukemia and pancreatic cancer. CureTech is about to initiate an international Phase II trial on patients suffering from metastatic melanoma, a severe condition with few treatment options.
"We are very pleased to have achieved this major milestone in the clinical development of CT-011" Schickler says, adding that following the final results of the study to be completed by the end of this year, "CureTech will be ready to commence Phase III regulatory studies for the high unmet need in this severe indication," a necessary step for approval by the US Food and Drug Administration.
"It’s an excellent indication of the capabilities of CT-011," says Schickler, "and I have no doubt that our product will make a major contribution to efforts to fight many types of cancer."