The Boston biotech IPO train may be starting up again. After a couple of slow months, obesity drugmaker Zafgen has brought in $96 million in its Nasdaq debut and saw its stock price rise more than 20 percent. And Syndax Pharmaceuticals has been preparing to go public this week; the Waltham company is working on an experimental drug for breast cancer. Meanwhile, Cambridge-based Sage Therapeutics has filed its paperwork for an IPO down the road. Sage is working on a number of new drug candidates that target neurological disorders. So, that’s three interesting companies to watch this summer.

In other innovation news:

— Local venture-capital firms are on the move. Boston’s Polaris Partners is raising $400 million in a new fund, according to a report in Fortune. And Bain Capital Partners has reportedly raised at least double that across two funds.

— Our startup of the week is Navitor Pharmaceuticals. The Cambridge startup has raised $23.5 million from Boston VCs and big pharma companies, to tackle autoimmune and metabolic disorders.

— And lastly, will 2015 be the year of wireless power? MIT spinout WiTricity thinks so, and it’s targeting consumer electronics, cars, and healthcare. The idea of charging batteries wirelessly has been around for a while, but new CEO Alex Gruzen thinks partnerships with Intel and automotive companies give his startup a leg up in what could become a very interesting market.