By Maxx Chatsko The lungs have evolved to keep things out. Can these biotech stocks get drugs in? You inhale and exhale over 20,000 times per day. Air, dust, pollen, and millions of bacteria and viruses. Thankfully, 3 billion years of evolution has led to formidable defenses. Our lungs are really, really good at keeping foreign objects out. Our immune system is really good at tackling anything that slips through. That’s great for survival, but not so good for drug developers. Over 23 clinical trials have evaluated genetic medicines for lung diseases and disorders ranging from cystic fibrosis t…